Introduction

Summary of Issues with the "Evidence-Based Osteokinematic Analysis"

Evidence-based Muscular Approach

Short and Overactive

Long and Overactive

Long and Underactive

Muscle Dysfunction: Summary of Research

Introduction of Fascia into a Predictive Model of Movement Impairment

Crural Fascia

Plantar Fascia and Achilles Tendon

Iliotibial Band

Osteokinematic Dysfunction

Fascial Dysfunction: Summary of Research

Myofascial Synergy a.k.a. Subsystems

Posterior Oblique Subsystem

Anterior Oblique Subsystem

Deep Longitudinal Subsystem

Myofascial Subsystems: Summary of Research

Arthrokinematic Dysfunction

Ankle Joint

Knee Joint

Muscular Dysfunction

Hip Joint

Arthorkinematic Dysfunction: Summary of Research

Symptoms, injuries and diagnoses associated with Lower Extremity Dysfunction LED

Thank You

Fascial Dysfunction

Myofascial Synergies

Considering the Traditional Model of Lower Extremity Dysfunction

Signs of Lower Extremity Dysfunction

Lower Extremity Dysfunction (LED): Predictive Model of Lower Extremity Movement Impairment

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Lower Extremity Dysfunction (LED)

Lower Extremity Dysfunction

Course Description: Lower Extremity Dysfunction (LED)

For an introduction to <a id="posture" data-tip="1659" target="_blank" href="/glossary-term/posture" class="glossary">Postural</a> Dysfunction and <a id="movement-impairment" data-tip="1575" target="_blank" href="/glossary-term/movement-impairment" class="glossary">Movement Impairment</a> please refer to:
<span style="background-color: transparent; font-family: inherit; font-size: inherit; font-style: inherit; font-variant-ligatures: inherit; font-variant-caps: inherit; font-weight: inherit; letter-spacing: 0px;"><a href="https://brookbushinstitute.com/article/introduction-to-postural-dysfunction-and-movement-impairment" style="letter-spacing: 0px;" target="_blank" rel="noopener">Introduction to </a><a id="posture" data-tip="1659" target="_blank" href="/glossary-term/posture" class="glossary">Postural</a> Dysfunction and Movement Impairment
&#x201C;Lower Extremity Dysfunction (LED)&quot; is a purposely chosen title for the impairment discussed in this article. By naming this <a id="model" data-tip="1469" target="_blank" href="/glossary-term/model" class="glossary">model</a> after body segment the risk is reduced that the title itself will imply a certain set of altered <a id="osteokinematic-motion" data-tip="1881" target="_blank" href="/glossary-term/osteokinematic-motion" class="glossary">osteokinematic</a> and <a id="arthrokinematics" data-tip="1702" target="_blank" href="/glossary-term/arthrokinematics" class="glossary">arthrokinematic motions</a>, changes in <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> activity, fascial dysfunction/loss of <a id="extensibility-2" data-tip="1308" target="_blank" href="/glossary-term/extensibility-2" class="glossary">extensibility</a>, and/or changes in sensation, perception, organization, and <a id="motor-unit" data-tip="1303" target="_blank" href="/glossary-term/motor-unit" class="glossary">motor unit</a> recruitment via the central <a id="nervous-system" data-tip="1690" target="_blank" href="/glossary-term/nervous-system" class="glossary">nervous system</a>. Common compensation patterns leading to LED have been previously described as &#x201C;pronation&quot; or &quot;pronation dysfunction&quot; (1-6). It is my opinion, these labels may be misleading because they imply a poorly defined set of joint motions. For example, pronation has been used to describe the motion of the ankle, the motion of the forefoot, or haphazardly as a synonym for excessive eversion. The most common use of the term &quot;pronation&quot; implies a combination of joint actions that occur around the oblique axis of the <a href="https://brookbushinstitute.com/article/ankle-joint-talocrural-subtalor-tibiofibular-joints" target="_blank" rel="noopener">tibiotalar joint</a> - dorsiflexion, abduction, and eversion.
However, excessive eversion and a lack of dorsiflexion are common findings in those exhibiting lower extremity impairment. If we continue to use a title for this <a id="model" data-tip="1469" target="_blank" href="/glossary-term/model" class="glossary">model</a> that implies a <a id="specificity" data-tip="1224" target="_blank" href="/glossary-term/specificity" class="glossary">specific</a> set of motions (e.g. &quot;pronation&quot; or &quot;pronation dysfunction&quot;), does it describe motions that are excessive, restricted, both, and if both, how is the human movement professional expected to differentiate? Now, consider a <a id="model" data-tip="1469" target="_blank" href="/glossary-term/model" class="glossary">model</a> described by body segment. The <a id="model" data-tip="1469" target="_blank" href="/glossary-term/model" class="glossary">model</a> may evolve without influence from the label used to describe it. The <a id="model" data-tip="1469" target="_blank" href="/glossary-term/model" class="glossary">model</a> may continue to evolve with ever-increasing detail and <a id="accuracy" data-tip="1218" target="_blank" href="/glossary-term/accuracy" class="glossary">accuracy</a> as new theoretical constructs, research, techniques, and outcome measures increase our knowledge of impairment for that segment.
LED is limited to common impairments of the <a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">hip</a>, <a href="https://brookbushinstitute.com/article/knee" target="_blank" rel="noopener">knee</a>, and <a href="https://brookbushinstitute.com/article/ankle-joint-talocrural-subtalor-tibiofibular-joints" target="_blank" rel="noopener">ankle (and </a><a id="proximal" data-tip="1564" target="_blank" href="/glossary-term/proximal" class="glossary">proximal</a> and <a id="distal" data-tip="1563" target="_blank" href="/glossary-term/distal" class="glossary">distal</a> tibiofibular joints respectively). It should be noted that this <a id="model" data-tip="1469" target="_blank" href="/glossary-term/model" class="glossary">model</a> purposely excludes the foot, despite evidence that LED may result in, or result from altered motion of the foot. The foot will be covered in a separate article for reasons related to education and practice. First, with respect to education, it is easier to retain, comprehend, and practice this information if the lower extremity and foot are initially treated as separate segments. Second, whereas LED may be successfully, and nearly comprehensively addressed using self-administered techniques, comprehensive intervention for foot dysfunction seems to necessitate certain manual techniques. This implies that all human movement professionals may have success addressing LED, whereas foot dysfunction should likely be addressed by licensed professionals whose scope includes joint mobilizations. The line separating the two <a id="movement-impairment" data-tip="1579" target="_blank" href="/glossary-term/movement-impairment" class="glossary">dysfunctions</a> is the transverse tarsal joint. That is to say that this <a id="model" data-tip="1469" target="_blank" href="/glossary-term/model" class="glossary">model</a> does not describe dysfunctional joint motion more <a id="distal" data-tip="1563" target="_blank" href="/glossary-term/distal" class="glossary">distal</a> than the talus and calcaneus.
<img src="https://www.datocms-assets.com/25800/1641826258-overhead-squat-assessment-17-sig-1-1.jpg"> OHSA with Modification (Heel Rise)

Summary of Model

<table border="1" height="350" style="border-collapse: collapse;">
 <tbody>
 <tr>
 <td>Commonly observed/studied impairments:
 <ul>
 <li><a href="https://brookbushinstitute.com/video/dorsiflexion-goniometry" target="_blank" rel="noopener">Loss of dorsiflexion</a> (inadequate forward translation of the knee, i.e. tibia on foot dorsiflexion)</li>
 <li><a href="https://brookbushinstitute.com/video/overhead-squat-assessment-4-feet-flat-breakdown" target="_blank" rel="noopener">Feet Flatten</a> (a.k.a. functional pes planus, pronation, eversion, calcaneus valgus, positive navicular drop <a id="assessment" data-tip="1482" target="_blank" href="/glossary-term/assessment" class="glossary">test</a>, etc.)</li>
 <li><a href="https://brookbushinstitute.com/video/feet-turn-out-breakdown" target="_blank" rel="noopener">Feet turn out</a> (a.k.a. turn-out, heel flare, heel whip, etc.)</li>
 <li><a href="https://brookbushinstitute.com/video/overhead-squat-assessment-6-knees-bow-in-breakdown" target="_blank" rel="noopener">Knees Bow In</a> (a.k.a. functional knee valgus, <a id="medial" data-tip="1568" target="_blank" href="/glossary-term/medial" class="glossary">medial</a> knee displacement, hip adduction, etc.)</li>
 <li><a href="https://brookbushinstitute.com/video/overhead-squat-assessment-8-excessive-forward-lean" target="_blank" rel="noopener">Excessive Forward Lean</a> (excessive hip flexion, forward trunk position, tibia/torso angle)</li>
 </ul>
 </td>
 <td>Recommended Assessment:
 <ul>
 <li><a href="https://brookbushinstitute.com/article/sign-clusters-compensation-patterns-overhead-squat-assessment" target="_blank" rel="noopener">Overhead Squat Assessment:</a>
 <ul>
 <li><a href="https://brookbushinstitute.com/video/overhead-squat-assessment-4-feet-flat-breakdown" target="_blank" rel="noopener">Feet flatten</a></li>
 <li><a href="https://brookbushinstitute.com/video/feet-turn-out-breakdown" target="_blank" rel="noopener">Feet turn-out</a></li>
 <li><a href="https://brookbushinstitute.com/video/overhead-squat-assessment-6-knees-bow-in-breakdown" target="_blank" rel="noopener">Knees bow-in</a></li>
 <li><a href="https://brookbushinstitute.com/video/overhead-squat-assessment-7-knees-bow-out" target="_blank" rel="noopener">Knees bow-out</a></li>
 <li><a href="https://brookbushinstitute.com/video/overhead-squat-assessment-9-anterior-pelvic-tilt-excessive-lordosis" target="_blank" rel="noopener">Excessive lordosis (</a><a id="anterior" data-tip="1566" target="_blank" href="/glossary-term/anterior" class="glossary">Anterior</a> pelvic tilt)</li>
 <li><a href="https://brookbushinstitute.com/video/overhead-squat-assessment-8-excessive-forward-lean" target="_blank" rel="noopener">Excessive forward lean</a></li>
 <li><a href="https://brookbushinstitute.com/video/overhead-squat-assessment-15-sign-clusters-asymmetrical-weight-shift" target="_blank" rel="noopener">Asymmetrical Weight Shift</a></li>
 </ul>
 </li>
 </ul>
 </td>
 </tr>
 </tbody>
</table>

<table border="1" height="702" style="border-collapse: collapse;">
 <tbody>
 <tr>
 <td>Short/Over-active
 <ul>
 <li>Plantar Flexors
 <ul>
 <li><a href="https://brookbushinstitute.com/article/gastrocnemius-plantaris" target="_blank" rel="noopener">Gastrocnemius</a></li>
 <li><a href="https://brookbushinstitute.com/article/soleus" target="_blank" rel="noopener">Soleus</a></li>
 <li><a href="https://brookbushinstitute.com/article/fibularis-muscles" target="_blank" rel="noopener">Fibularis Muscles</a></li>
 <li><a href="https://brookbushinstitute.com/article/flexor-hallucis-longus-and-flexor-digitorum-longus" target="_blank" rel="noopener">Flexor Hallucis Longus and Flexor Digitorum Longus</a></li>
 </ul>
 </li>
 <li>Tibia External Rotators
 <ul>
 <li><a href="https://brookbushinstitute.com/article/tensor-fascia-latae-tfl" target="_blank" rel="noopener">Tensor Fasciae Latae (TFL)</a></li>
 <li><a href="https://brookbushinstitute.com/article/quadriceps-vastus-muscles" target="_blank" rel="noopener">Vastus Lateralis</a></li>
 <li>Short head of <a href="https://brookbushinstitute.com/article/biceps-femoris" target="_blank" rel="noopener">Biceps Femoris</a></li>
 </ul>
 </li>
 <li>Hip Internal Rotators
 <ul>
 <li><a href="https://brookbushinstitute.com/article/gluteus-minimus" target="_blank" rel="noopener">Gluteus Minimus</a> (and<a href="https://brookbushinstitute.com/article/gluteus-minimus" target="_blank" rel="noopener"> TFL</a>)</li>
 <li><a href="https://brookbushinstitute.com/article/adductors" target="_blank" rel="noopener">Anterior Adductors</a></li>
 </ul>
 </li>
 <li><a href="https://brookbushinstitute.com/article/rectus-femoris" target="_blank" rel="noopener">Rectus Femoris</a></li>
 </ul>
 </td>
 <td>Recommended Assessments:
 <ul>
 <li><a href="https://brookbushinstitute.com/article/lower-body-goniometry" target="_blank" rel="noopener">Goniometry: Lower Body</a></li>
 <li><a href="https://brookbushinstitute.com/article/muscle-length-tests" target="_blank" rel="noopener">Muscles Length Tests</a></li>
 </ul>
 <h4>Recommended Techniques:</h4>
 <ul>
 <li><a href="https://brookbushinstitute.com/article/hip-internal-rotator-release-and-lengthening-tfl-gluteus-minimus-adductors" target="_blank" rel="noopener">Hip Internal Rotator: </a><a id="release" data-tip="1249" target="_blank" href="/glossary-term/release" class="glossary">Release</a> and Lengthening</li>
 <li><a href="https://brookbushinstitute.com/article/hip-flexor-flexibility" target="_blank" rel="noopener">Hip Flexor: </a><a id="release" data-tip="1249" target="_blank" href="/glossary-term/release" class="glossary">Release</a> and Lengthening</li>
 <li><a href="https://brookbushinstitute.com/article/lateral-thigh-flexibility" target="_blank" rel="noopener">Tibial External Rotator: </a><a id="release" data-tip="1249" target="_blank" href="/glossary-term/release" class="glossary">Release</a> and Lengthening</li>
 <li><a href="https://brookbushinstitute.com/article/lower-leg-flexibility" target="_blank" rel="noopener">Plantar Flexor and Evertor: </a><a id="release" data-tip="1249" target="_blank" href="/glossary-term/release" class="glossary">Release</a> and Lengthening</li>
 </ul>
 </td>
 </tr>
 <tr>
 <td>Long/Under-active
 <ul>
 <li>Invertors
 <ul>
 <li><a href="https://brookbushinstitute.com/article/tibialis-anterior" target="_blank" rel="noopener">Tibialis Anterior</a></li>
 <li><a href="https://brookbushinstitute.com/article/tibialis-posterior" target="_blank" rel="noopener">Tibialis Posterior</a></li>
 </ul>
 </li>
 <li>Tibial Internal Rotators
 <ul>
 <li><a href="https://brookbushinstitute.com/article/adductors" target="_blank" rel="noopener">Gracilis</a></li>
 <li><a href="https://brookbushinstitute.com/article/popliteus" target="_blank" rel="noopener">Popliteus</a></li>
 <li><a href="https://brookbushinstitute.com/article/semitendinosus-and-semimembranosus" target="_blank" rel="noopener">Semitendinosus and Semimembranosus</a></li>
 <li><a href="https://brookbushinstitute.com/article/quadriceps-vastus-muscles" target="_blank" rel="noopener">Vastus Medialis Obliquus</a></li>
 </ul>
 </li>
 <li>Hip External Rotators
 <ul>
 <li><a href="https://brookbushinstitute.com/article/gluteus-medius" target="_blank" rel="noopener">Gluteus Medius</a></li>
 <li><a href="https://brookbushinstitute.com/article/piriformis" target="_blank" rel="noopener">Gluteus Maximus</a></li>
 </ul>
 </li>
 </ul>
 </td>
 <td>Recommended Assessments
 <ul>
 <li><a href="https://brookbushinstitute.com/article/lower-body-manual-muscle-testing" target="_blank" rel="noopener">Manual </a><a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">Muscle</a> Testing: Lower Body</li>
 </ul>
 <h4>Recommended Techniques</h4>
 <ul>
 <li><a href="https://brookbushinstitute.com/article/gluteus-medius-activation-progression" target="_blank" rel="noopener">Gluteus Medius Activation</a></li>
 <li><a href="https://brookbushinstitute.com/article/gluteus-maximus-activation" target="_blank" rel="noopener">Gluteus Maximus Activation</a></li>
 <li><a href="https://brookbushinstitute.com/article/tibial-internal-rotator-activation" target="_blank" rel="noopener">Tibial Internal Rotator Activation</a></li>
 <li><a href="https://brookbushinstitute.com/article/vmo-activation" target="_blank" rel="noopener">VMO Activation</a></li>
 <li><a href="https://brookbushinstitute.com/article/posterior-tibialis-activation" target="_blank" rel="noopener">Tibialis </a><a id="posterior" data-tip="1565" target="_blank" href="/glossary-term/posterior" class="glossary">Posterior</a> Activation</li>
 <li><a href="https://brookbushinstitute.com/article/tibialis-anterior-activation" target="_blank" rel="noopener">Tibialis </a><a id="anterior" data-tip="1566" target="_blank" href="/glossary-term/anterior" class="glossary">Anterior</a> Activation</li>
 </ul>
 </td>
 </tr>
 <tr>
 <td>Long/Over-active (Synergistically Dominant &#x2013; <a href="https://brookbushinstitute.com/articles?category=flexibility" target="_blank" rel="noopener">Release Only</a>)
 <ul>
 <li><a id="synergists" data-tip="1650" target="_blank" href="/glossary-term/synergists" class="glossary">Synergists</a> of Dorsiflexion
 <ul>
 <li><a href="https://brookbushinstitute.com/article/extensor-hallucis-longus-and-extensor-digitorum-longus-fibularis-tertius" target="_blank" rel="noopener">Extensor Hallucis Longus and Extensor Digitorum Longus</a></li>
 </ul>
 </li>
 <li><a id="synergists" data-tip="1650" target="_blank" href="/glossary-term/synergists" class="glossary">Synergists</a> of hip External Rotation
 <ul>
 <li><a href="https://brookbushinstitute.com/article/piriformis" target="_blank" rel="noopener">Piriformis</a> and <a href="https://brookbushinstitute.com/article/deep-rotators-of-the-hip" target="_blank" rel="noopener">Deep Rotators</a></li>
 <li><a href="https://brookbushinstitute.com/article/adductors" target="_blank" rel="noopener">Adductor Magnus</a></li>
 <li><a href="https://brookbushinstitute.com/article/biceps-femoris" target="_blank" rel="noopener">Biceps Femoris</a></li>
 <li><a href="https://brookbushinstitute.com/article/sartorius" target="_blank" rel="noopener">Sartorius</a></li>
 </ul>
 </li>
 </ul>
 </td>
 <td></td>
 </tr>
 </tbody>
</table>
<img src="https://www.datocms-assets.com/25800/1649100996-muscle-tissue.jpg" title="Muscle tissue" alt="Muscle tissue">

<table border="1" height="259" style="border-collapse: collapse;">
 <tbody>
 <tr>
 <td>Restricted Mobility (Thickening, histochemical changes, decrease in tensile strength, addition of disordered collagen fibers)
 <ul>
 <li>Sacrotuberous ligament</li>
 <li>Iliotibial Band</li>
 <li>Crural Fascia</li>
 <li>Achilles Tendon</li>
 <li>Plantar Fascia</li>
 </ul>
 </td>
 <td>Recommended Techniques
 <ul>
 <li><a href="https://brookbushinstitute.com/video/vastus-lateralis-self-administered-dynamic-release-a-k-a-pin-stretch" target="_blank" rel="noopener">Vastus Lateralis (ITB) Dynamic Release</a></li>
 <li><a href="https://brookbushinstitute.com/video/gastrocnemius-and-soleus-self-administered-dynamic-release-a-k-a-pin-stretch" target="_blank" rel="noopener">Calf (Crural Fascia) Dynamic Release</a></li>
 </ul>
 <h4>Additional manual techniques:</h4>
 <ul>
 <li>Instrument Assisted Soft Tissue Mobilization</li>
 <li>Pin and Stretch</li>
 </ul>
 </td>
 </tr>
 </tbody>
</table>
<img src="https://www.datocms-assets.com/25800/1649100927-fascia-web-in-body.jpg" title="Fascia" alt="Fascial web ">

<table border="1" height="365" style="border-collapse: collapse;">
 <tbody>
 <tr>
 <td>Under-active (Integrate)
 <ul>
 <li><a href="https://brookbushinstitute.com/article/posterior-oblique-subsystem-pos" target="_blank" rel="noopener">Posterior Oblique Subsystem</a></li>
 </ul>
 <h4>Over-active (Release and Avoid)</h4>
 <ul>
 <li><a href="https://brookbushinstitute.com/article/anterior-oblique-subsystem-aos" target="_blank" rel="noopener">Anterior Oblique Subsystem</a></li>
 <li><a href="https://brookbushinstitute.com/article/deep-longitudinal-subsystem" target="_blank" rel="noopener">Deep Longitudinal Subsystem</a></li>
 </ul>
 </td>
 <td>Integration
 <ul>
 <li><a href="https://brookbushinstitute.com/article/bridge-progression" target="_blank" rel="noopener">Bridges</a></li>
 <li><a href="https://brookbushinstitute.com/article/axe-chop-progression" target="_blank" rel="noopener">Chops</a></li>
 <li><a href="https://brookbushinstitute.com/article/stability-progression-for-integrated-exercise" target="_blank" rel="noopener">Legs with Pull</a></li>
 </ul>
 <h4>Release</h4>
 <ul>
 <li><a href="https://brookbushinstitute.com/article/hip-external-rotator-flexibility" target="_blank" rel="noopener">Hip External Rotator: </a><a id="release" data-tip="1249" target="_blank" href="/glossary-term/release" class="glossary">Release</a> and Lengthening</li>
 </ul>
 <h4>Avoid</h4>
 <ul>
 <li><a href="https://brookbushinstitute.com/article/plank-progression" target="_blank" rel="noopener">Planks</a></li>
 <li><a href="https://brookbushinstitute.com/article/crunch-progression" target="_blank" rel="noopener">Crunches</a></li>
 <li>Leg Raises</li>
 <li>Hamstring Curls</li>
 </ul>
 </td>
 </tr>
 </tbody>
</table>

Myofascial Synergies (Subsystems)

<table border="1" height="358" style="border-collapse: collapse;">
 <tbody>
 <tr>
 <td>Mobility Restriction (Stiffness)
 <ul>
 <li><a href="https://brookbushinstitute.com/article/ankle-joint-talocrural-subtalor-tibiofibular-joints" target="_blank" rel="noopener">Ankle</a>: Inadequate <a id="posterior" data-tip="1565" target="_blank" href="/glossary-term/posterior" class="glossary">posterior</a> <a href="https://brookbushinstitute.com/glossary/glide/" target="_blank" rel="noopener">glide</a> of the talus on the tibia</li>
 <li><a href="https://brookbushinstitute.com/article/ankle-joint-talocrural-subtalor-tibiofibular-joints" target="_blank" rel="noopener">Ankle</a>: Inadequate <a id="posterior" data-tip="1565" target="_blank" href="/glossary-term/posterior" class="glossary">posterior</a> <a href="https://brookbushinstitute.com/glossary/glide/" target="_blank" rel="noopener">glide</a> of the <a href="https://brookbushinstitute.com/glossary/lateral/" target="_blank" rel="noopener">lateral</a> malleolus on the tibia</li>
 <li><a href="https://brookbushinstitute.com/article/ankle-joint-talocrural-subtalor-tibiofibular-joints" target="_blank" rel="noopener">Ankle</a>/<a href="https://brookbushinstitute.com/article/knee" target="_blank" rel="noopener">Knee</a>: Inadequate <a id="anterior" data-tip="1566" target="_blank" href="/glossary-term/anterior" class="glossary">anterior</a> <a href="https://brookbushinstitute.com/glossary/glide/" target="_blank" rel="noopener">glide</a> of the fibular head on the tibia</li>
 <li><a href="https://brookbushinstitute.com/article/knee" target="_blank" rel="noopener">Knee</a>: Inadequate <a id="anterior" data-tip="1566" target="_blank" href="/glossary-term/anterior" class="glossary">anterior</a> <a id="glide" data-tip="1598" target="_blank" href="/glossary-term/glide" class="glossary">glide</a> of the tibia on the femur (the <a id="lateral" data-tip="1567" target="_blank" href="/glossary-term/lateral" class="glossary">lateral</a> compartment may be more restricted)</li>
 <li><a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">Hip</a>: Inadequate posterior/inferior <a id="glide" data-tip="1598" target="_blank" href="/glossary-term/glide" class="glossary">glide</a> of the femur in the acetabulum</li>
 </ul>
 </td>
 <td>Recommended Assessments:
 <ul>
 <li>Passive <a id="arthrokinematics" data-tip="1860" target="_blank" href="/glossary-term/arthrokinematics" class="glossary">Accessory Motion</a> Assessment</li>
 </ul>
 <h4>Recommended Techniques:</h4>
 <ul>
 <li><a href="https://brookbushinstitute.com/article/joint-mobilization-lower-body-self-administered" target="_blank" rel="noopener">Self-administered Joint Mobilization: Lower Body</a></li>
 </ul>
 </td>
 </tr>
 </tbody>
</table>
<img src="https://www.datocms-assets.com/25800/1649099275-glute-max-reactive-activation.png">

Arthrokinematic Dysfunctions

The first issue with this <a id="model" data-tip="1469" target="_blank" href="/glossary-term/model" class="glossary">model</a> is attempting to identify how pronation and supination would affect <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> length and activity. There are very few &#x201C;true pronators&#x201D; and &#x201C;true supinators&#x201D; of the ankle. If we used these joint actions alone, our analysis would exclude the gross majority of structures crossing the ankle. For this reason, we have broken down the complex actions of pronation and supination into their component joint actions. Pronation is comprised of plantar flexion, eversion, and abduction; however, abduction has been removed from the graph below, as the muscles that contribute to abduction would also be evertors. Supination is comprised of dorsiflexion, inversion, and adduction; however, adduction has been removed from the graph below, as the <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> that contributes to adduction would also be invertors.
<table>
 <tbody>
 <tr>
 <td colspan="4" width="779">
 <h3>Pronation Dysfunction</h3>
 </td>
 </tr>
 <tr>
 <td colspan="2" width="390">Short</td>
 <td colspan="2" width="390">Long</td>
 </tr>
 <tr>
 <td width="195">Ankle Plantar Flexion</td>
 <td width="195">
 <ul>
 <li><a href="https://brookbushinstitute.com/article/gastrocnemius-plantaris" target="_blank" rel="noopener">Gastrocnemius and Plantaris</a></li>
 <li><a href="https://brookbushinstitute.com/article/soleus" target="_blank" rel="noopener">Soleus</a></li>
 <li><a href="https://brookbushinstitute.com/article/tibialis-posterior" target="_blank" rel="noopener">Tibialis Posterior</a></li>
 <li><a href="https://brookbushinstitute.com/article/fibularis-muscles" target="_blank" rel="noopener">Fibularis Longus and Fibularis Brevis</a>,</li>
 <li><a href="https://brookbushinstitute.com/article/flexor-hallucis-longus-and-flexor-digitorum-longus" target="_blank" rel="noopener">Flexor Hallucis Longus and Flexor Digitorum Longus</a></li>
 </ul>
 </td>
 <td width="195">Ankle Dorsiflexion</td>
 <td width="195">
 <ul>
 <li><a href="https://brookbushinstitute.com/article/tibialis-anterior" target="_blank" rel="noopener">Tibialis Anterior</a>,</li>
 <li><a href="https://brookbushinstitute.com/article/extensor-hallucis-longus-and-extensor-digitorum-longus-fibularis-tertius" target="_blank" rel="noopener">Extensor Hallucis Longus, Extensor Digitorum Longus and Fibularis Tertius</a></li>
 </ul>
 </td>
 </tr>
 <tr>
 <td width="195">Ankle Eversion</td>
 <td width="195">
 <ul>
 <li><a href="https://brookbushinstitute.com/article/fibularis-muscles" target="_blank" rel="noopener">Fibularis Longus and Fibularis Brevis</a></li>
 <li><a href="https://brookbushinstitute.com/article/gastrocnemius-plantaris" target="_blank" rel="noopener">Lateral Gastrocnemius</a></li>
 <li><a href="https://brookbushinstitute.com/article/soleus" target="_blank" rel="noopener">Soleus</a></li>
 <li><a href="https://brookbushinstitute.com/article/flexor-hallucis-longus-and-flexor-digitorum-longus" target="_blank" rel="noopener">Flexor Digitorum Longus</a></li>
 </ul>
 </td>
 <td width="195">Ankle Inversion</td>
 <td width="195">
 <ul>
 <li><a href="https://brookbushinstitute.com/article/tibialis-anterior" target="_blank" rel="noopener">Tibialis Anterior</a></li>
 <li><a href="https://brookbushinstitute.com/article/tibialis-posterior" target="_blank" rel="noopener">Tibialis Posterior</a></li>
 <li><a href="https://brookbushinstitute.com/article/gastrocnemius-plantaris" target="_blank" rel="noopener">Medial Gastrocnemius</a></li>
 <li><a href="https://brookbushinstitute.com/article/flexor-hallucis-longus-and-flexor-digitorum-longus" target="_blank" rel="noopener">Flexor Hallucis Longus</a></li>
 </ul>
 </td>
 </tr>
 </tbody>
</table>
The second issue with this <a id="model" data-tip="1469" target="_blank" href="/glossary-term/model" class="glossary">model</a> is the number of muscles that have been listed on both the short and long sides of the graph (in bold). Since a <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> cannot be both shortened and lengthened around the same joint this represents an incongruity; at the very least it represents a point of confusion and possibly conflicting ideas about <a id="optimal" data-tip="1571" target="_blank" href="/glossary-term/optimal" class="glossary">optimal</a> intervention. If a graph exhibits only a few muscles that appear on both sides we may be able to &#x201C;label&quot; the muscles as &#x201C;long/over-active&#x201D; - a common state of muscles acting as <a href="https://brookbushinstitute.com/article/overactive-synergists-cheat-sheet" target="_blank" rel="noopener">over-active synergists</a>, or &#x201C;short/under-active&#x201D; a common state of &quot;inhibited <a id="prime-mover" data-tip="1663" target="_blank" href="/glossary-term/prime-mover" class="glossary">prime movers</a>.&quot; Although both of these scenarios are legitimate possibilities, they are also relatively rare; only accounting for a small portion of muscles in each of the predictive <a id="model" data-tip="1471" target="_blank" href="/glossary-term/model" class="glossary">models</a> of dysfunction. Using these rationales in abundance can only lead to ineloquent analyses, like the table above. Further, this leads to fairly crude practice, as a <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> appearing on both sides of the table may be a rationale to use both <a id="mobility" data-tip="1455" target="_blank" href="/glossary-term/mobility" class="glossary">mobility</a> and <a id="activation-technique" data-tip="1531" target="_blank" href="/glossary-term/activation-technique" class="glossary">activation techniques</a> on the same <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a>. In my humble opinion, a table with so many muscles on &quot;both sides,&quot; should be an indication that further thought should be given to the joint actions that represent the <a id="movement-impairment" data-tip="1575" target="_blank" href="/glossary-term/movement-impairment" class="glossary">movement impairment</a> noted.
Third, the table above does not allow for a detailed analysis of changes in <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> activity (<a id="tone" data-tip="1639" target="_blank" href="/glossary-term/tone" class="glossary">tone</a>). Initially, it is possible to reason that short muscles are over-active, citing that over-activity may be a reason for the adaptively shortened position, or for creating the noted excessive motion, and the inverse can be said of long muscles, stating that under-activity allows for muscles to be &quot;pulled&quot; into a lengthened position, and reduces their ability to eccentrically decelerate the dysfunctional motion. However, this simple categorization of short muscles as over-active, and long muscles as under-active does not explain &quot;synergistic dominance,&quot; &quot;prime mover inhibition,&quot; &quot;pattern overload,&quot; and other maladaptive changes in <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> activity and recruitment.
The fourth issue with the <a id="model" data-tip="1469" target="_blank" href="/glossary-term/model" class="glossary">model</a> above is the omission of several joints. For example, a sign commonly noted in those exhibiting LED is &#x201C;<a href="https://brookbushinstitute.com/video/overhead-squat-assessment-5-feet-turn-out-breakdown" target="_blank" rel="noopener">feet turn out</a>.&#x201D; The amount of &quot;turn-out&quot; observed in those with significant dysfunction (often 20-45&#xB0;) cannot be achieved via subtalar abduction alone (15). As this often occurs during sitting, sit-to-stand transfers, and at the bottom squat, lunge, and <a id="bilateral" data-tip="1552" target="_blank" href="/glossary-term/bilateral" class="glossary">bilateral</a> jumping patterns, the turn-out cannot be credited to femoral external rotation either - femoral external rotation at the bottom of a squat would bring the feet together as if to assume the &quot;lotus position&quot; in yoga. <a href="https://brookbushinstitute.com/video/overhead-squat-assessment-5-feet-turn-out-breakdown" target="_blank" rel="noopener">Feet turn out</a>, must be a function of tibial external rotation at the <a href="https://brookbushinstitute.com/article/knee" target="_blank" rel="noopener">knee</a> (<a id="optimal" data-tip="1571" target="_blank" href="/glossary-term/optimal" class="glossary">optimal</a> available range for tibial external rotation = 45&#xB0;(15)). This implies that the <a href="https://brookbushinstitute.com/article/knee" target="_blank" rel="noopener">knee</a> should be included in a <a id="model" data-tip="1469" target="_blank" href="/glossary-term/model" class="glossary">model</a> of LED. As many of the rotators of the <a href="https://brookbushinstitute.com/article/knee" target="_blank" rel="noopener">knee</a> also cross the hip; this implies that <a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">hip</a> mechanics may also be affected. We can make further biomechanical inferences regarding the relationship between the <a href="https://brookbushinstitute.com/article/knee" target="_blank" rel="noopener">knee</a> and <a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">hip</a>, considering that tibia external rotation is relative to femoral internal rotation. Later in this article, research will be discussed that demonstrates a relationship between <a href="https://brookbushinstitute.com/article/ankle-joint-talocrural-subtalor-tibiofibular-joints" target="_blank" rel="noopener">ankle</a> and <a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">hip</a> motion. Even the <a id="proximal" data-tip="1564" target="_blank" href="/glossary-term/proximal" class="glossary">proximal</a> and <a id="distal" data-tip="1563" target="_blank" href="/glossary-term/distal" class="glossary">distal</a> tibiofibular joints play a role, but as their motions are best described as <a id="glide" data-tip="1815" target="_blank" href="/glossary-term/glide" class="glossary">slide</a> and <a id="roll" data-tip="1602" target="_blank" href="/glossary-term/roll" class="glossary">roll</a> their inclusion in the LED <a id="model" data-tip="1469" target="_blank" href="/glossary-term/model" class="glossary">model</a> will be limited to <a id="arthrokinematics" data-tip="1863" target="_blank" href="/glossary-term/arthrokinematics" class="glossary">arthrokinematic</a> analysis.
Fifth, this <a id="model" data-tip="1469" target="_blank" href="/glossary-term/model" class="glossary">model</a> misses analysis that would infer the use of effective techniques intended to alleviate <a id="arthrokinematics" data-tip="1863" target="_blank" href="/glossary-term/arthrokinematics" class="glossary">arthrokinematic</a> dysfunction (mobilizations, manipulations, <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> energy techniques) and fascial dysfunction (pin and stretch, myofascial <a id="release" data-tip="1249" target="_blank" href="/glossary-term/release" class="glossary">release</a>, IASTM, etc). That is to say that the traditional <a id="model" data-tip="1469" target="_blank" href="/glossary-term/model" class="glossary">model</a> of &quot;Pronation Dysfunction&quot; does not consider <a id="arthrokinematics" data-tip="1859" target="_blank" href="/glossary-term/arthrokinematics" class="glossary">arthrokinematics</a> or fascial <a id="dyskinesis" data-tip="1693" target="_blank" href="/glossary-term/dyskinesis" class="glossary">dyskinesis</a>. If the body is an adaptable, <a id="integration" data-tip="1473" target="_blank" href="/glossary-term/integration" class="glossary">integrated</a> system then all tissue systems should be accounted for. Further, an <a id="integration" data-tip="1473" target="_blank" href="/glossary-term/integration" class="glossary">integrated</a> <a id="model" data-tip="1469" target="_blank" href="/glossary-term/model" class="glossary">model</a> of practice would include a rationale for the effectiveness of all evidence-supported techniques. Additional analysis and consideration of research regarding <a id="arthrokinematics" data-tip="1859" target="_blank" href="/glossary-term/arthrokinematics" class="glossary">arthrokinematics</a> and fascia will be needed if the LED <a id="model" data-tip="1469" target="_blank" href="/glossary-term/model" class="glossary">model</a> is to be a comprehensive <a id="model" data-tip="1469" target="_blank" href="/glossary-term/model" class="glossary">model</a> of lower extremity impairments.
Last, despite considerable research correlating pain and altered movement, the analysis above does not attempt to identify related diagnoses and pathologies.
<h4>Summary of Issues with the &quot;Traditional&quot; Model:</h4>
<ul>
 <li>Pronation is a term that is used differently by different professions to describe various aspects of foot/ankle motion, and therefore, is poorly defined.</li>
 <li>Several joints that are likely related to these impairments have been omitted; this is discussed in detail under an &quot;Evidence-based <a id="osteokinematic-motion" data-tip="1881" target="_blank" href="/glossary-term/osteokinematic-motion" class="glossary">Osteokinematic</a> Analysis&quot;</li>
 <li>Muscles appear on both long and short sides of the table without a clear reason (muscles cannot be long and short at the same time).</li>
 <li>Description of this <a id="model" data-tip="1469" target="_blank" href="/glossary-term/model" class="glossary">model</a> does not allow for analysis of <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> activity of all muscles crossing the ankle.</li>
 <li>Fascial structures have been excluded from this analysis.</li>
 <li>Arthorkinematic dysfunction has been excluded from this analysis.</li>
 <li>No attempt is made in this analysis to identify diagnoses and pathologies related to LED.</li>
</ul>
<img src="https://www.datocms-assets.com/25800/1649099326-genu-valgum-angle.png">
Donald A. Neumann, &#x201C;Kinesiology of the Musculoskeletal System: Foundations of Rehabilitation &#x2013; 2nd Edition&#x201D; &#xA9; 2012 Mosby, Inc.

As mentioned above, the LED <a id="model" data-tip="1469" target="_blank" href="/glossary-term/model" class="glossary">model</a> could be defined by those impairments that appear in the body of research, as well as the synonyms used and/or similar impairments. This includes:
<ul>
 <li><a href="https://brookbushinstitute.com/video/dorsiflexion-goniometry" target="_blank" rel="noopener">Loss of dorsiflexion</a> (inadequate forward translation of the knee, i.e. tibia on foot dorsiflexion)</li>
 <li><a href="https://brookbushinstitute.com/video/overhead-squat-assessment-4-feet-flat-breakdown" target="_blank" rel="noopener">Feet Flatten</a> (a.k.a. functional pes planus, pronation, eversion, calcaneus valgus, positive navicular drop <a id="assessment" data-tip="1482" target="_blank" href="/glossary-term/assessment" class="glossary">test</a>, etc.)</li>
 <li><a href="https://brookbushinstitute.com/video/overhead-squat-assessment-6-knees-bow-in-breakdown" target="_blank" rel="noopener">Knees Bow In</a> (a.k.a. functional knee valgus, <a id="medial" data-tip="1568" target="_blank" href="/glossary-term/medial" class="glossary">medial</a> knee displacement, hip adduction, etc.)</li>
 <li><a href="https://brookbushinstitute.com/video/feet-turn-out-breakdown" target="_blank" rel="noopener">Feet turn out</a> (a.k.a. turn-out, heel flare, heel whip, etc.)</li>
 <li><a href="https://brookbushinstitute.com/video/overhead-squat-assessment-8-excessive-forward-lean" target="_blank" rel="noopener">Excessive Forward Lean</a> (excessive hip flexion, forward trunk position, tibia/torso angle)</li>
</ul>
Note: in this case, &quot;functional&quot; is used as an adjective describing altered motion that is not caused by structural change or congenital abnormalities.

<ul>
 <li><a href="https://brookbushinstitute.com/video/dorsiflexion-goniometry" target="_blank" rel="noopener">Loss of Dorsiflexion</a>: Decreased dorsiflexion may be the most common &quot;driver&quot; of compensation in the lower extremity. Several studies have noted a link between decreased dorsiflexion, alterations in lower extremity alignment, and altered <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> recruitment during functional tasks (18-20, 23-28). That is, a decrease in dorsiflexion has been identified in studies investigating <a href="https://brookbushinstitute.com/video/overhead-squat-assessment-8-excessive-forward-lean" target="_blank" rel="noopener">excessive forward lean</a>, <a href="https://brookbushinstitute.com/video/overhead-squat-assessment-6-knees-bow-in-breakdown" target="_blank" rel="noopener">functional knee valgus</a>, <a href="https://brookbushinstitute.com/video/feet-turn-out-breakdown" target="_blank" rel="noopener">feet turn out</a>, and a <a href="https://brookbushinstitute.com/video/overhead-squat-assessment-4-feet-flat-breakdown" target="_blank" rel="noopener">functional pes planus</a>. Further, many of these studies correlated these patterns with commonly noted ankle and knee pathologies (<a id="medial" data-tip="1568" target="_blank" href="/glossary-term/medial" class="glossary">medial</a> knee pain, Achilles tendonitis, etc.). Although not commonly correlated with dysfunction unto itself, one study did show that <a href="https://brookbushinstitute.com/article/lower-leg-flexibility" target="_blank" rel="noopener">self-administered </a><a id="release" data-tip="1249" target="_blank" href="/glossary-term/release" class="glossary">release</a> and stretching of the calf complex was effective for the treatment of plantar heel pain, with dorsiflexion being an outcome measure (43).</li>
 <li><a href="https://brookbushinstitute.com/video/overhead-squat-assessment-4-feet-flat-breakdown" target="_blank" rel="noopener">Feet Flatten</a> (Functional Pes Planus) - Increased pronation has been associated with injuries ranging from <a id="medial" data-tip="1568" target="_blank" href="/glossary-term/medial" class="glossary">medial</a> tibial stress syndrome (shin splints) to tibialis <a id="posterior" data-tip="1565" target="_blank" href="/glossary-term/posterior" class="glossary">posterior</a> tendonitis, Achilles bursitis or tendinitis, patellofemoral disorders, iliotibial friction syndrome, and lower extremity stress fractures (29 - 39, 44, 48). It has been suggested that a combination of excessive pronation and internal tibial rotation (at the ankle) is a better predictor of the development of overuse injuries than either alone, especially of the <a href="https://brookbushinstitute.com/article/knee" target="_blank" rel="noopener">knee</a> joint (40-42). This combination of <a href="https://brookbushinstitute.com/article/ankle-joint-talocrural-subtalor-tibiofibular-joints" target="_blank" rel="noopener">ankle</a>, tibia, and <a href="https://brookbushinstitute.com/article/knee" target="_blank" rel="noopener">knee</a> motions infers a connection with this sign/impairment <a href="https://brookbushinstitute.com/video/feet-turn-out-breakdown" target="_blank" rel="noopener">feet turn out</a> discussed below. In a study by Trimble et al., the sign was assessed with a lower extremity <a href="https://brookbushinstitute.com/glossary/posture/" target="_blank" rel="noopener">posture</a> <a href="https://brookbushinstitute.com/glossary/assessment/" target="_blank" rel="noopener">test</a> and was found to be a more <a id="reliability" data-tip="1795" target="_blank" href="/glossary-term/reliability" class="glossary">reliable</a> indicator of tibial translation than recurvatum or thigh/foot angle (20). Further, excessive eversion has been linked to excessive <a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">hip</a> internal rotation during gait (25).</li>
 <li><a href="https://brookbushinstitute.com/video/overhead-squat-assessment-5-feet-turn-out-breakdown" target="_blank" rel="noopener">Feet Turn Out</a> &#x2013; Only two studies have correlated feet turn-out with dysfunction. In a study by Winslow et al., <a href="https://brookbushinstitute.com/video/feet-turn-out-breakdown" target="_blank" rel="noopener">feet turn out</a> was correlated with a positive &#x201C;<a href="https://brookbushinstitute.com/video/obers-test-tfl-flexibility-assessment" target="_blank" rel="noopener">Ober&#x2019;s Test</a>&#x201D; (<a href="https://brookbushinstitute.com/article/tensor-fascia-latae-tfl" target="_blank" rel="noopener">tensor fascia latae</a> restriction/over-active) and <a href="https://brookbushinstitute.com/article/knee" target="_blank" rel="noopener">knee</a> pain (46), and in a study by Andrew et al., feet turn out was correlated with a functional varus and linked to <a href="https://brookbushinstitute.com/article/knee" target="_blank" rel="noopener">knee</a> osteoarthritis (47). Another potential example of this dysfunction may be &quot;medial heel whip&quot;; a sign studied in runners in which the heel tracks <a id="medial" data-tip="1568" target="_blank" href="/glossary-term/medial" class="glossary">medial</a> during early swing. In a study by Souza et al., a <a id="medial" data-tip="1568" target="_blank" href="/glossary-term/medial" class="glossary">medial</a> heel whip of greater than 5&#xB0; was noted in approximately 27% of individuals (45), although further study is needed to correlate this sign with pathology and recruitment. It is worth noting that tibial external rotation may also be a component of &#x201C;<a href="https://brookbushinstitute.com/video/overhead-squat-assessment-6-knees-bow-in-breakdown" target="_blank" rel="noopener">Knees Bow In</a>&#x201D; (functional valgus), as femoral internal rotation can be viewed as relative tibial external rotation during closed chain activities.</li>
 <li><a href="https://brookbushinstitute.com/video/overhead-squat-assessment-6-knees-bow-in-breakdown" target="_blank" rel="noopener">Knees Bow In</a> (functional valgus) &#x2013; Research has correlated a functional valgus with a decrease in <a href="https://brookbushinstitute.com/article/gluteus-maximus" target="_blank" rel="noopener">gluteus maximus</a> and <a href="https://brookbushinstitute.com/article/gluteus-medius" target="_blank" rel="noopener">medius</a> activity, sacroiliac joint dysfunction, excessive <a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">hip</a> internal rotation and adduction, a loss of dorsiflexion, and excessive pronation (16, 23, 44 - 60). Studies have also correlated this sign of dysfunction with increased risk of <a href="https://brookbushinstitute.com/glossary/anterior/" target="_blank" rel="noopener">anterior</a> cruciate ligament (ACL) injury and patellofemoral pain (ACL) (16, 50, 51). Several studies have also noted the effectiveness of <a id="specificity" data-tip="1224" target="_blank" href="/glossary-term/specificity" class="glossary">specific</a> exercise interventions for correcting this dysfunction (23, 56 - 57).</li>
 <li><a href="https://brookbushinstitute.com/video/overhead-squat-assessment-8-excessive-forward-lean" target="_blank" rel="noopener">Excessive Forward Lean</a> &#x2013; Two studies have shown a relationship between dorsiflexion restriction and excessive hip flexion during squatting (in conjunction with other changes in lower extremity kinematics) (55, 61). Two additional studies have demonstrated a decrease in <a href="https://brookbushinstitute.com/article/gluteus-maximus" target="_blank" rel="noopener">gluteus maximus</a> strength and activity related to ankle dysfunction (42, 62), which may partially explain the inability to maintain an upright <a href="https://brookbushinstitute.com/glossary/posture/" target="_blank" rel="noopener">posture</a>.</li>
</ul>
Based on this research, external rotation of the tibia, hip flexion, and hip internal rotation should be added to the analysis of LED (again, muscles in red appear on both sides of the graph).
<table>
 <tbody>
 <tr>
 <td colspan="4" width="779">
 <h3>Lower Extremity Dysfunction based on Research of Impairments</h3>
 </td>
 </tr>
 <tr>
 <td colspan="2" width="390">Short</td>
 <td colspan="2" width="390">Long</td>
 </tr>
 <tr>
 <td width="195">Ankle Plantar Flexion (Loss of Dorsiflexion)</td>
 <td width="195">
 <ul>
 <li><a href="https://brookbushinstitute.com/article/gastrocnemius-plantaris" target="_blank" rel="noopener">Gastrocnemius and Plantaris</a></li>
 <li><a href="https://brookbushinstitute.com/article/soleus" target="_blank" rel="noopener">Soleus</a></li>
 <li><a href="https://brookbushinstitute.com/article/tibialis-posterior" target="_blank" rel="noopener">Tibialis Posterior</a></li>
 <li><a href="https://brookbushinstitute.com/article/fibularis-muscles" target="_blank" rel="noopener">Fibularis Longus and Fibularis Brevis</a>,</li>
 <li><a href="https://brookbushinstitute.com/article/flexor-hallucis-longus-and-flexor-digitorum-longus" target="_blank" rel="noopener">Flexor Hallucis Longus and Flexor Digitorum Longus</a></li>
 </ul>
 </td>
 <td width="195">Ankle Dorsiflexion</td>
 <td width="195">
 <ul>
 <li><a href="https://brookbushinstitute.com/article/tibialis-anterior" target="_blank" rel="noopener">Tibialis Anterior</a>,</li>
 <li><a href="https://brookbushinstitute.com/article/extensor-hallucis-longus-and-extensor-digitorum-longus-fibularis-tertius" target="_blank" rel="noopener">Extensor Hallucis Longus, Extensor Digitorum Longus and Fibularis Tertius</a></li>
 </ul>
 </td>
 </tr>
 <tr>
 <td width="195">Ankle Eversion</td>
 <td width="195">
 <ul>
 <li><a href="https://brookbushinstitute.com/article/fibularis-muscles" target="_blank" rel="noopener">Fibularis Longus and Fibularis Brevis</a></li>
 <li><a href="https://brookbushinstitute.com/article/gastrocnemius-plantaris" target="_blank" rel="noopener">Lateral Gastrocnemius</a></li>
 <li><a href="https://brookbushinstitute.com/article/soleus" target="_blank" rel="noopener">Soleus</a></li>
 <li><a href="https://brookbushinstitute.com/article/flexor-hallucis-longus-and-flexor-digitorum-longus" target="_blank" rel="noopener">Flexor Digitorum Longus</a></li>
 </ul>
 </td>
 <td width="195">Ankle Inversion</td>
 <td width="195">
 <ul>
 <li><a href="https://brookbushinstitute.com/article/tibialis-anterior" target="_blank" rel="noopener">Tibialis Anterior</a></li>
 <li><a href="https://brookbushinstitute.com/article/tibialis-posterior" target="_blank" rel="noopener">Tibialis Posterior</a></li>
 <li><a href="https://brookbushinstitute.com/article/gastrocnemius-plantaris" target="_blank" rel="noopener">Medial Gastrocnemius</a></li>
 <li><a href="https://brookbushinstitute.com/article/flexor-hallucis-longus-and-flexor-digitorum-longus" target="_blank" rel="noopener">Flexor Hallucis Longus</a></li>
 </ul>
 </td>
 </tr>
 <tr>
 <td width="195">Tibia External Rotation</td>
 <td width="195">
 <ul>
 <li><a href="https://brookbushinstitute.com/article/biceps-femoris" target="_blank" rel="noopener">Biceps Femoris</a></li>
 <li><a href="https://brookbushinstitute.com/article/tensor-fascia-latae-tfl" target="_blank" rel="noopener">Tensor Fascia Latae</a></li>
 <li><a href="https://brookbushinstitute.com/article/gastrocnemius-plantaris" target="_blank" rel="noopener">Lateral Gastrocnemius</a></li>
 </ul>
 </td>
 <td width="195">Tibia Internal Rotation</td>
 <td width="195">
 <ul>
 <li><a href="https://brookbushinstitute.com/article/adductors" target="_blank" rel="noopener">Gracilis</a></li>
 <li><a href="https://brookbushinstitute.com/article/semitendinosus-and-semimembranosus" target="_blank" rel="noopener">Semitendinosus &amp; Semimembranosus</a></li>
 <li><a href="https://brookbushinstitute.com/article/sartorius" target="_blank" rel="noopener">Sartorius</a></li>
 <li><a href="https://brookbushinstitute.com/article/anatomy-articles/muscular-anatomy/popliteus/" target="_blank" rel="noopener">Popliteus</a></li>
 <li><a href="https://brookbushinstitute.com/article/gastrocnemius-plantaris" target="_blank" rel="noopener">Medial Gastrocnemius</a>
 
 </li>
 <li><a href="https://brookbushinstitute.com/article/quadriceps-vastus-muscles" target="_blank" rel="noopener">Vastus Medialis Obliquus</a></li>
 </ul>
 </td>
 </tr>
 <tr>
 <td width="195">Hip Internal Rotation</td>
 <td width="195">
 <ul>
 <li><a href="https://brookbushinstitute.com/article/tensor-fascia-latae-tfl" target="_blank" rel="noopener">Tensor Fascia Latae</a></li>
 <li><a href="https://brookbushinstitute.com/article/adductors" target="_blank" rel="noopener">Anterior Adductors</a></li>
 <li><a href="https://brookbushinstitute.com/article/gluteus-minimus" target="_blank" rel="noopener">Gluteus Minimus</a></li>
 </ul>
 </td>
 <td width="195">Hip External Rotation</td>
 <td width="195">
 <ul>
 <li><a href="https://brookbushinstitute.com/article/gluteus-medius" target="_blank" rel="noopener">Gluteus Medius</a>,</li>
 <li><a href="https://brookbushinstitute.com/article/gluteus-maximus" target="_blank" rel="noopener">Gluteus Maximus</a></li>
 <li><a href="https://brookbushinstitute.com/article/piriformis" target="_blank" rel="noopener">Piriformis</a></li>
 <li><a href="https://brookbushinstitute.com/article/deep-rotators-of-the-hip" target="_blank" rel="noopener">Deep Rotators of the Hip</a></li>
 <li><a href="https://brookbushinstitute.com/article/biceps-femoris" target="_blank" rel="noopener">Biceps Femoris</a></li>
 </ul>
 </td>
 </tr>
 <tr>
 <td width="195">Hip Flexion</td>
 <td width="195">
 <ul>
 <li><a href="https://brookbushinstitute.com/article/tensor-fascia-latae-tfl" target="_blank" rel="noopener">Tensor Fascia Latae</a></li>
 <li><a href="https://brookbushinstitute.com/article/adductors" target="_blank" rel="noopener">Anterior Adductors</a></li>
 <li><a href="https://brookbushinstitute.com/article/gluteus-minimus" target="_blank" rel="noopener">Gluteus Minimus</a></li>
 <li><a href="https://brookbushinstitute.com/article/psoas" target="_blank" rel="noopener">Psoas</a></li>
 <li><a href="https://brookbushinstitute.com/article/iliacus" target="_blank" rel="noopener">Iliacus</a></li>
 <li><a href="https://brookbushinstitute.com/article/rectus-femoris" target="_blank" rel="noopener">Rectus Femoris</a></li>
 </ul>
 </td>
 <td width="195">Hip Extension</td>
 <td width="195">
 <ul>
 <li><a href="https://brookbushinstitute.com/article/gluteus-medius" target="_blank" rel="noopener">Gluteus Medius</a></li>
 <li><a href="https://brookbushinstitute.com/article/gluteus-maximus" target="_blank" rel="noopener">Gluteus Maximus</a></li>
 <li><a href="https://brookbushinstitute.com/article/semitendinosus-and-semimembranosus" target="_blank" rel="noopener">Semitendinosus &amp; Semimembranosus</a></li>
 <li><a href="https://brookbushinstitute.com/article/biceps-femoris" target="_blank" rel="noopener">Biceps Femoris</a></li>
 <li><a href="https://brookbushinstitute.com/article/adductors" target="_blank" rel="noopener">Adductor Magnus</a></li>
 </ul>
 </td>
 </tr>
 </tbody>
</table>

The <a id="evidence-based-practice" data-tip="1538" target="_blank" href="/glossary-term/evidence-based-practice" class="glossary">evidence-based</a> <a id="osteokinematic-motion" data-tip="1881" target="_blank" href="/glossary-term/osteokinematic-motion" class="glossary">osteokinematic</a> analysis solves many of the issues that exist in the &quot;traditional <a id="model" data-tip="1469" target="_blank" href="/glossary-term/model" class="glossary">model</a>.&quot; This includes a more accurate account of excessive joint motions, and which joints should be included in the <a id="model" data-tip="1469" target="_blank" href="/glossary-term/model" class="glossary">model</a>. Further, using just the research cited in the development of this analysis more could be said about the altered activity of certain muscles (although we will discuss this in the next section), and the relationship between LED and some diagnoses, pathologies, and symptoms.
Remaining issues:
<ul>
 <li>Muscles appear on both long and short sides of the table without a clear reason (muscles cannot be long and short at the same time).</li>
 <li>Analysis of altered <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> activity is incomplete.</li>
 <li>Fascial structures have been excluded from this analysis.</li>
 <li>Arthorkinematic dysfunction has been excluded from this analysis.</li>
 <li>A list of diagnoses and pathologies related to LED is incomplete.</li>
</ul>
<img src="https://www.datocms-assets.com/25800/1649099391-robert-griffin.jpg" alt="Robert Griffin III functional valgus.">
Robert Griffin III during a vertical jump <a id="assessment" data-tip="1482" target="_blank" href="/glossary-term/assessment" class="glossary">test</a> his rookie year. Note his knees bow in, a.k.a. functional valgus.

To create a detailed <a id="model" data-tip="1469" target="_blank" href="/glossary-term/model" class="glossary">model</a> of practice, a <a id="model" data-tip="1469" target="_blank" href="/glossary-term/model" class="glossary">model</a> that will help to refine exercise selection, further analysis is required to determine the relative changes in activity of all muscles included in LED. In this &quot;level of analysis,&quot; an attempt is made to aggregate all <a id="relevance" data-tip="1505" target="_blank" href="/glossary-term/relevance" class="glossary">relevant</a> research on all muscles included in the <a id="model" data-tip="1469" target="_blank" href="/glossary-term/model" class="glossary">model</a>.
<img src="https://www.datocms-assets.com/25800/1649100835-length-tension.jpeg" title="Length Tension Relationship" alt="Length Tension Relationship (shortened muscles and lengthened muscles produce lower potential force)">

Evidence-Based Muscular Approach

Short/Over-active

<a href="https://brookbushinstitute.com/article/biceps-femoris" target="_blank" rel="noopener">Biceps Femoris</a>, <a href="https://brookbushinstitute.com/article/piriformis" target="_blank" rel="noopener">Piriformis</a>, <a href="https://brookbushinstitute.com/article/deep-rotators-of-the-hip" target="_blank" rel="noopener">Deep Rotators</a>, and <a href="https://brookbushinstitute.com/article/biceps-femoris" target="_blank" rel="noopener">Adductor Magnus</a> - Four studies have demonstrated an increase in <a href="https://brookbushinstitute.com/article/biceps-femoris" target="_blank" rel="noopener">biceps femoris</a> activity relative to <a href="https://brookbushinstitute.com/article/gluteus-maximus" target="_blank" rel="noopener">gluteus maximus</a> activity. In these studies, the changes were noted in those exhibiting an <a href="https://brookbushinstitute.com/glossary/anterior/" target="_blank" rel="noopener">anterior</a> pelvic tilt, lumbar spine <a id="stability" data-tip="1193" target="_blank" href="/glossary-term/stability" class="glossary">instability</a>, sacroiliac joint dysfunction, and knee valgus (28, 76-78). Further, stretching the <a href="https://brookbushinstitute.com/article/biceps-femoris" target="_blank" rel="noopener">biceps femoris</a> has been shown to result in a relative increase in <a href="https://brookbushinstitute.com/article/quadriceps-vastus-muscles" target="_blank" rel="noopener">vastus medialis obliquus (VMO)</a> activity (79), which begs consideration of potential over-activity resulting in altered <a id="reciprocal-inhibition" data-tip="1655" target="_blank" href="/glossary-term/reciprocal-inhibition" class="glossary">reciprocal inhibition</a>. A potentially important note is the relative increase in length the <a href="https://brookbushinstitute.com/article/biceps-femoris" target="_blank" rel="noopener">biceps femoris</a> would have to adopt if excessive hip internal rotation is noted, as seen in a <a href="https://brookbushinstitute.com/video/overhead-squat-assessment-6-knees-bow-in-breakdown" target="_blank" rel="noopener">functional knee valgus</a> and by definition in this analysis of LED. Studies have shown foam rolling of the hamstrings to be an effective strategy for increasing flexibility without decreasing performance (80); however, based on the relative increase in length due to internal rotation of the femur, the Brookbush Institute (BI) does not recommend stretching this <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a>. Very few studies have examined the activity of the <a href="https://brookbushinstitute.com/article/piriformis" target="_blank" rel="noopener">piriformis</a> (and none have investigated the <a href="https://brookbushinstitute.com/article/deep-rotators-of-the-hip" target="_blank" rel="noopener">deep rotators</a> to our knowledge); this is likely due to inaccessibility via surface EMG. The <a href="https://brookbushinstitute.com/article/piriformis" target="_blank" rel="noopener">piriformis</a> has been shown to be more active during external rotation, abduction, and extension of the femur, and when &quot;on stretch&quot; contributes to stiffness (<a id="compression" data-tip="1595" target="_blank" href="/glossary-term/compression" class="glossary">compression</a>) of the sacroiliac joint (SIJ) (81-83). This may imply a key role in the <a id="compensation-pattern" data-tip="1696" target="_blank" href="/glossary-term/compensation-pattern" class="glossary">compensation pattern</a> <a href="https://brookbushinstitute.com/video/overhead-squat-assessment-7-knees-bow-out" target="_blank" rel="noopener">Knees Bow Out</a> (Functional Varus); however, as most dysfunction of the lower extremity results in excessive hip internal rotation during functional tasks, it may be correct to assume an increase in length, which may increase SIJ stiffness. Clinically, palpation of the <a href="https://brookbushinstitute.com/article/piriformis" target="_blank" rel="noopener">piriformis</a> would imply this <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> is commonly over-active. There is some research to <a id="base-of-support" data-tip="1197" target="_blank" href="/glossary-term/base-of-support" class="glossary">support</a> piriformis <a id="trigger-point" data-tip="1634" target="_blank" href="/glossary-term/trigger-point" class="glossary">trigger points</a> being common, occurring in 25 - 50% of the population (14, 84), and <a id="release" data-tip="1249" target="_blank" href="/glossary-term/release" class="glossary">release</a> has proven to be good practice clinically. Again as this <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> is commonly lengthened by dysfunction, stretching is not recommended. Due to similar anatomic functions, the <a href="https://brookbushinstitute.com/article/deep-rotators-of-the-hip" target="_blank" rel="noopener">deep rotators</a> are treated like the <a href="https://brookbushinstitute.com/article/piriformis" target="_blank" rel="noopener">piriformis</a>.
Our knowledge of <a href="https://brookbushinstitute.com/article/adductors" target="_blank" rel="noopener">adductor magnus</a> activity is hampered by a void in the research. Three older publications suggest that despite the <a href="https://brookbushinstitute.com/article/adductors" target="_blank" rel="noopener">adductors</a> being active throughout gait, the <a id="posterior" data-tip="1565" target="_blank" href="/glossary-term/posterior" class="glossary">posterior</a> or &quot;ischiocondylar&quot; head of the <a href="https://brookbushinstitute.com/article/adductors" target="_blank" rel="noopener">adductor magnus</a> has a recruitment pattern that is similar to the hamstrings (14, 85, 86). That is, the <a id="posterior" data-tip="1565" target="_blank" href="/glossary-term/posterior" class="glossary">posterior</a> head of the <a href="https://brookbushinstitute.com/article/adductors" target="_blank" rel="noopener">adductor magnus</a> is an extensor, an external rotator, and is active during mid stance, push-off, and late swing of gait. Anatomically, this <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> does share an origin with the <a href="https://brookbushinstitute.com/article/biceps-femoris" target="_blank" rel="noopener">biceps femoris</a> on the sacrotuberous ligament and has neural innervation from the sciatic <a id="nerve-cell" data-tip="1361" target="_blank" href="/glossary-term/nerve-cell" class="glossary">nerve</a> via the tibial <a id="nerve-cell" data-tip="1361" target="_blank" href="/glossary-term/nerve-cell" class="glossary">nerve</a> (much like the hamstrings). Throughout the Brookbush Institute content, the term &quot;<a href="https://brookbushinstitute.com/article/adductors" target="_blank" rel="noopener">adductor magnus</a>&quot; is used to reference the <a id="posterior" data-tip="1565" target="_blank" href="/glossary-term/posterior" class="glossary">posterior</a> head of the <a href="https://brookbushinstitute.com/article/adductors" target="_blank" rel="noopener">adductor magnus</a>, and this <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> is addressed in the same manner as the <a href="https://brookbushinstitute.com/article/biceps-femoris" target="_blank" rel="noopener">biceps femoris</a>. The <a id="anterior" data-tip="1566" target="_blank" href="/glossary-term/anterior" class="glossary">anterior</a> head of the <a href="https://brookbushinstitute.com/article/adductors" target="_blank" rel="noopener">adductor magnus</a> is considered with the group that entails all other adductors, referred to as the &quot;anterior <a href="https://brookbushinstitute.com/article/adductors" target="_blank" rel="noopener">adductors</a>.&quot;
<a href="https://brookbushinstitute.com/article/extensor-hallucis-longus-and-extensor-digitorum-longus-fibularis-tertius" target="_blank" rel="noopener">Extensor Hallucis Longus (EHL)</a>, <a href="https://brookbushinstitute.com/article/extensor-hallucis-longus-and-extensor-digitorum-longus-fibularis-tertius" target="_blank" rel="noopener">Extensor Digitorum Longus (EDL)</a>, <a href="https://brookbushinstitute.com/article/flexor-hallucis-longus-and-flexor-digitorum-longus" target="_blank" rel="noopener">Flexor Hallucis Longus (FHL)</a>, and <a href="https://brookbushinstitute.com/article/flexor-hallucis-longus-and-flexor-digitorum-longus" target="_blank" rel="noopener">Flexor Digitorum Longus (FDL)</a> - The EHL and EDL assist the <a href="https://brookbushinstitute.com/article/tibialis-anterior" target="_blank" rel="noopener">tibialis anterior</a> with dorsiflexion during the swing phase of gait and aid in eccentric deceleration of plantarflexion during heel strike (107). The EHL, FHL, and FDL assist in the stabilization of the <a id="medial" data-tip="1568" target="_blank" href="/glossary-term/medial" class="glossary">medial</a> longitudinal arch (along with <a href="https://brookbushinstitute.com/article/tibialis-anterior" target="_blank" rel="noopener">tibialis anterior</a> and <a href="https://brookbushinstitute.com/article/tibialis-posterior" target="_blank" rel="noopener">tibialis posterior</a>) during mid-stance and in the maintenance of medial-lateral <a id="balance" data-tip="1190" target="_blank" href="/glossary-term/balance" class="glossary">balance</a> during gait. The EDL may assist in eversion/pronation, likely acting as a <a id="synergists" data-tip="1854" target="_blank" href="/glossary-term/synergists" class="glossary">synergist</a> to the <a href="https://brookbushinstitute.com/article/fibularis-muscles" target="_blank" rel="noopener">Fibularis Muscles</a> (106). Although these muscles are synergistic to muscles that play an important role in opposing <a href="https://brookbushinstitute.com/video/overhead-squat-assessment-4-feet-flat-breakdown" target="_blank" rel="noopener">feet flatten</a>, research related to &quot;hammertoes&quot; and &quot;claw toes&quot; suggests a propensity toward over-activity (108). It is our <a id="hypothesis" data-tip="1446" target="_blank" href="/glossary-term/hypothesis" class="glossary">hypothesis</a> that these muscles act as <a id="synergistic-dominance" data-tip="1647" target="_blank" href="/glossary-term/synergistic-dominance" class="glossary">over-active synergists</a> for inhibited invertors (lengthened by eversion and excessive plantar flexion). That is, in attempting to <a id="compensation-pattern" data-tip="1697" target="_blank" href="/glossary-term/compensation-pattern" class="glossary">compensate</a> for much larger muscles in the movement of the ankle, over-activity, excessive force production, and toe dysfunction results. <a id="synergistic-dominance" data-tip="1647" target="_blank" href="/glossary-term/synergistic-dominance" class="glossary">over-active synergists</a> should likely be <a id="release" data-tip="1253" target="_blank" href="/glossary-term/release" class="glossary">released</a>, but not stretched or activated.

Long/Over-active (Over-active Synergists)

Long/Under-active

<ul>
 <li>It is likely that the <a href="https://brookbushinstitute.com/article/fibularis-muscles" target="_blank" rel="noopener">fibularis longus, fibularis brevis,</a> <a href="https://brookbushinstitute.com/article/flexor-hallucis-longus-and-flexor-digitorum-longus" target="_blank" rel="noopener">flexor hallucis longus, flexor digitorum longus</a>, <a href="https://brookbushinstitute.com/article/flexor-hallucis-longus-and-flexor-digitorum-longus" target="_blank" rel="noopener">extensor hallucis longus, extensor digitorum longus</a>, and the <a href="https://brookbushinstitute.com/article/tibialis-posterior" target="_blank" rel="noopener">tibialis posterior</a> can/should be assessed based on their frontal plane contributions, and their contribution to sagittal plane motion should be ignored at this time. This is due to their relatively small contribution to plantarflexion/dorsiflexion force, the low correlation between <a href="https://brookbushinstitute.com/video/overhead-squat-assessment-4-feet-flat-breakdown" target="_blank" rel="noopener">feet flatten</a> and calcaneus valgus, and the research on these muscles being biased toward the investigation of pronation. Further research is needed examining the impact of restricted dorsiflexion on <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> activity; however, it is our <a id="hypothesis" data-tip="1446" target="_blank" href="/glossary-term/hypothesis" class="glossary">hypothesis</a> that this will not change the categorization of these muscles below.</li>
 <li>Both heads of the <a href="https://brookbushinstitute.com/article/gastrocnemius-plantaris" target="_blank" rel="noopener">gastrocnemius</a> likely contribute to eversion.</li>
 <li>The <a href="https://brookbushinstitute.com/article/tensor-fascia-latae-tfl" target="_blank" rel="noopener">tensor fascia latae</a>, <a href="https://brookbushinstitute.com/article/sartorius" target="_blank" rel="noopener">sartorius</a>, <a href="https://brookbushinstitute.com/article/quadriceps-vastus-muscles" target="_blank" rel="noopener">vastus lateralis</a>, and <a href="https://brookbushinstitute.com/article/rectus-femoris" target="_blank" rel="noopener">rectus femoris</a> appear to behave similarly. Although <a href="https://brookbushinstitute.com/article/sartorius" target="_blank" rel="noopener">sartorius</a> and <a href="https://brookbushinstitute.com/article/rectus-femoris" target="_blank" rel="noopener">rectus femoris</a> activity in those exhibiting dysfunction should be researched further, an argument can be established with research to show similar changes in activity to the <a href="https://brookbushinstitute.com/article/tensor-fascia-latae-tfl" target="_blank" rel="noopener">tensor fascia latae</a> and <a href="https://brookbushinstitute.com/article/quadriceps-vastus-muscles" target="_blank" rel="noopener">vastus lateralis</a>.</li>
 <li>The <a href="https://brookbushinstitute.com/article/biceps-femoris" target="_blank" rel="noopener">biceps femoris</a>, <a href="https://brookbushinstitute.com/article/piriformis" target="_blank" rel="noopener">piriformis</a>, <a href="https://brookbushinstitute.com/article/deep-rotators-of-the-hip" target="_blank" rel="noopener">deep rotators of the hip (and adductor magnus</a>), despite being lengthened by internal rotation of the hip/femur, has a propensity toward over-activity.</li>
</ul>
In this graph &quot;red muscles&quot; are over-active, note that muscles no longer appear on both sides of the table.
<table>
 <tbody>
 <tr>
 <td colspan="4" width="779">
 <h3>Lower Extremity Dysfunction based on Myofascial Research</h3>
 </td>
 </tr>
 <tr>
 <td colspan="2" width="390">Short</td>
 <td colspan="2" width="390">Long</td>
 </tr>
 <tr>
 <td width="195">Ankle Plantar Flexion (Loss of Dorsiflexion)</td>
 <td width="195">
 <ul>
 <li><a href="https://brookbushinstitute.com/article/gastrocnemius-plantaris" target="_blank" rel="noopener">Gastrocnemius and Plantaris</a></li>
 <li><a href="https://brookbushinstitute.com/article/soleus" target="_blank" rel="noopener">Soleus</a></li>
 </ul>
 </td>
 <td width="195">Ankle Dorsiflexion</td>
 <td width="195">
 <ul>
 <li><a href="https://brookbushinstitute.com/article/tibialis-anterior" target="_blank" rel="noopener">Tibialis Anterior</a></li>
 </ul>
 </td>
 </tr>
 <tr>
 <td width="195">Ankle Eversion</td>
 <td width="195">
 <ul>
 <li><a href="https://brookbushinstitute.com/article/fibularis-muscles" target="_blank" rel="noopener">Fibularis Longus and Fibularis Brevis</a></li>
 <li><a href="https://brookbushinstitute.com/article/gastrocnemius-plantaris" target="_blank" rel="noopener">Gastrocnemius</a></li>
 <li><a href="https://brookbushinstitute.com/article/extensor-hallucis-longus-and-extensor-digitorum-longus-fibularis-tertius" target="_blank" rel="noopener">Extensor Digitorum Longus</a></li>
 </ul>
 </td>
 <td width="195">Ankle Inversion</td>
 <td width="195">
 <ul>
 <li><a href="https://brookbushinstitute.com/article/tibialis-anterior" target="_blank" rel="noopener">Tibialis Anterior</a></li>
 <li><a href="https://brookbushinstitute.com/article/tibialis-posterior" target="_blank" rel="noopener">Tibialis Posterior</a></li>
 <li><a href="https://brookbushinstitute.com/article/flexor-hallucis-longus-and-flexor-digitorum-longus" target="_blank" rel="noopener">Flexor Hallucis Longus and Flexor Digitorum Longus</a></li>
 </ul>
 </td>
 </tr>
 <tr>
 <td width="195">Tibia External Rotation</td>
 <td width="195">
 <ul>
 <li><a href="https://brookbushinstitute.com/article/biceps-femoris" target="_blank" rel="noopener">Biceps Femoris</a></li>
 <li><a href="https://brookbushinstitute.com/article/tensor-fascia-latae-tfl" target="_blank" rel="noopener">Tensor Fascia Latae</a></li>
 <li><a href="https://brookbushinstitute.com/article/quadriceps-vastus-muscles" target="_blank" rel="noopener">Vastus Lateralis</a></li>
 <li><a href="https://brookbushinstitute.com/article/rectus-femoris" target="_blank" rel="noopener">Rectus Femoris</a></li>
 <li><a href="https://brookbushinstitute.com/article/sartorius" target="_blank" rel="noopener">Sartorius</a></li>
 </ul>
 </td>
 <td width="195">Tibia Internal Rotation</td>
 <td width="195">
 <ul>
 <li><a href="https://brookbushinstitute.com/article/adductors" target="_blank" rel="noopener">Gracilis</a></li>
 <li><a href="https://brookbushinstitute.com/article/semitendinosus-and-semimembranosus" target="_blank" rel="noopener">Semitendinosus &amp; Semimembranosus</a></li>
 <li><a href="https://brookbushinstitute.com/article/anatomy-articles/muscular-anatomy/popliteus/" target="_blank" rel="noopener">Popliteus</a>
 
 </li>
 <li><a href="https://brookbushinstitute.com/article/quadriceps-vastus-muscles" target="_blank" rel="noopener">Vastus Medialis Obliquus</a></li>
 </ul>
 </td>
 </tr>
 <tr>
 <td width="195">Hip Internal Rotation</td>
 <td width="195">
 <ul>
 <li><a href="https://brookbushinstitute.com/article/tensor-fascia-latae-tfl" target="_blank" rel="noopener">Tensor Fascia Latae</a></li>
 <li><a href="https://brookbushinstitute.com/article/gluteus-minimus" target="_blank" rel="noopener">Gluteus Minimus</a></li>
 <li><a href="https://brookbushinstitute.com/article/adductors" target="_blank" rel="noopener">Anterior Adductors</a></li>
 </ul>
 </td>
 <td width="195">Hip External Rotation</td>
 <td width="195">
 <ul>
 <li><a href="https://brookbushinstitute.com/article/gluteus-medius" target="_blank" rel="noopener">Gluteus Medius</a>,</li>
 <li><a href="https://brookbushinstitute.com/article/gluteus-maximus" target="_blank" rel="noopener">Gluteus Maximus</a></li>
 <li><a href="https://brookbushinstitute.com/article/piriformis" target="_blank" rel="noopener">Piriformis</a></li>
 <li><a href="https://brookbushinstitute.com/article/deep-rotators-of-the-hip" target="_blank" rel="noopener">Deep Rotators of the Hip</a></li>
 <li><a href="https://brookbushinstitute.com/article/biceps-femoris" target="_blank" rel="noopener">Biceps Femoris</a></li>
 <li><a href="https://brookbushinstitute.com/article/adductors" target="_blank" rel="noopener">Adductor Magnus</a></li>
 </ul>
 </td>
 </tr>
 <tr>
 <td width="195">Hip Flexion</td>
 <td width="195">
 <ul>
 <li><a href="https://brookbushinstitute.com/article/tensor-fascia-latae-tfl" target="_blank" rel="noopener">Tensor Fascia Latae</a></li>
 <li><a href="https://brookbushinstitute.com/article/adductors" target="_blank" rel="noopener">Anterior Adductors</a></li>
 <li><a href="https://brookbushinstitute.com/article/gluteus-minimus" target="_blank" rel="noopener">Gluteus Minimus</a></li>
 <li><a href="https://brookbushinstitute.com/article/psoas" target="_blank" rel="noopener">Psoas</a></li>
 <li><a href="https://brookbushinstitute.com/article/iliacus" target="_blank" rel="noopener">Iliacus</a></li>
 <li><a href="https://brookbushinstitute.com/article/rectus-femoris" target="_blank" rel="noopener">Rectus Femoris</a></li>
 </ul>
 </td>
 <td width="195">Hip Extension</td>
 <td width="195">
 <ul>
 <li><a href="https://brookbushinstitute.com/article/gluteus-medius" target="_blank" rel="noopener">Gluteus Medius</a></li>
 <li><a href="https://brookbushinstitute.com/article/gluteus-maximus" target="_blank" rel="noopener">Gluteus Maximus</a></li>
 <li><a href="https://brookbushinstitute.com/article/semitendinosus-and-semimembranosus" target="_blank" rel="noopener">Semitendinosus &amp; Semimembranosus</a></li>
 <li><a href="https://brookbushinstitute.com/article/biceps-femoris" target="_blank" rel="noopener">Biceps Femoris</a></li>
 <li><a href="https://brookbushinstitute.com/article/adductors" target="_blank" rel="noopener">Adductor Magnus</a></li>
 </ul>
 </td>
 </tr>
 </tbody>
</table>
Summary of Issues with the &quot;Evidence-based Muscular Analysis&quot;:
The research used to construct an &quot;evidence-based muscular analysis,&quot; when used to refine the <a id="evidence-based-practice" data-tip="1538" target="_blank" href="/glossary-term/evidence-based-practice" class="glossary">evidence-based</a> <a id="osteokinematic-motion" data-tip="1881" target="_blank" href="/glossary-term/osteokinematic-motion" class="glossary">osteokinematic</a> analysis, offers a more refined account of changes in <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> activity. This offers several advantages when creating a corrective intervention; however, more research and further analysis is needed.
Remaining issues:
<ul>
 <li>Several muscles are treated like muscles with similar functions because no research exists that specifically investigates their activity relative to <a id="movement-impairment" data-tip="1575" target="_blank" href="/glossary-term/movement-impairment" class="glossary">movement impairment</a> (<a href="https://brookbushinstitute.com/article/gluteus-minimus" target="_blank" rel="noopener">gluteus minimus</a>, <a href="https://brookbushinstitute.com/article/rectus-femoris" target="_blank" rel="noopener">rectus femoris</a>, <a href="https://brookbushinstitute.com/article/sartorius" target="_blank" rel="noopener">sartorius</a>, <a href="https://brookbushinstitute.com/article/adductors" target="_blank" rel="noopener">gracilis</a>, <a href="https://brookbushinstitute.com/article/semitendinosus-and-semimembranosus" target="_blank" rel="noopener">semitendinosus &amp; semimembranosus</a>).</li>
 <li>EMG research is needed comparing the relative activity of all muscles in the lower leg (muscles crossing the ankle); maladaptive changes in relative activity may be hidden by a gross increase in activity of all lower leg muscles in those exhibiting dysfunction. (Palmieri et al. - ankle <a id="effusion" data-tip="1459" target="_blank" href="/glossary-term/effusion" class="glossary">effusion</a> increases ankle <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> activity (244))
 <ul>
 <li>The reason the <a href="https://brookbushinstitute.com/article/tibialis-anterior" target="_blank" rel="noopener">tibialis anterior</a> and <a href="https://brookbushinstitute.com/article/tibialis-posterior" target="_blank" rel="noopener">tibialis posterior</a> remain &quot;under-active&quot; in this table, despite research showing an increase in activity in those exhibiting dysfunction, is the additional research showing that activation/strengthening techniques for these muscles are effective in reducing dysfunction. Described later, <a id="activation-technique" data-tip="1531" target="_blank" href="/glossary-term/activation-technique" class="glossary">activation techniques</a> are specifically designed techniques to increase the activity of under-active muscles.</li>
 </ul>
 </li>
 <li>Based on the activity of the lower leg muscles (muscles crossing the ankle) it appears that a 3rd categorization (perhaps based on the timing of recruitment) may be necessary. Further, consideration must be given to the establishment of techniques designed to treat dysfunction related to this category (reactive activation).</li>
 <li>Fascial structures have been excluded from this analysis.</li>
 <li>Arthorkinematic dysfunction has been excluded from this analysis.</li>
 <li>The list of diagnoses and pathologies related to LED is incomplete.</li>
</ul>
<a href="https://brookbush.s3.us-east-2.amazonaws.com/wordpress/wp-content/uploads/2016/07/body_worlds_knee.bmp" target="_blank" rel="noopener"><img src="https://brookbush.s3.us-east-2.amazonaws.com/wordpress/wp-content/uploads/2016/07/body_worlds_knee.bmp" alt="Bodies World Exhibit - Iliotibial Band invest into the knee and anterior crural fascia"></a>
Bodies World Exhibit - Iliotibial Band invest into the knee and <a id="anterior" data-tip="1566" target="_blank" href="/glossary-term/anterior" class="glossary">anterior</a> crural fascia

Our understanding of fascia has benefited from an exponential increase in research over the past two decades. This includes research on its traditional functions as a passive medium that supports, protects, and encapsulates tissues (145), as well as being a tissue that stores energy for explosive activity via elastic deformation (146, 147). However, the most interesting new research implicates fascia as a medium of communication. Levangin hypothesized that this may occur via electrical, cellular, and/or mechanical signals (148). Histological studies have shown this tissue to be densely innervated by free <a id="nerve-cell" data-tip="1361" target="_blank" href="/glossary-term/nerve-cell" class="glossary">nerve</a> endings, as well as by Pacinian corpuscles and Ruffini endings (145, 146). These findings have inspired my analogy of fascia as &quot;nature&apos;s keyboard.&quot; Stecco et al. has demonstrated that deep fascia is arranged in layers that may <a id="glide" data-tip="1815" target="_blank" href="/glossary-term/glide" class="glossary">slide</a> over one another (147). This finding is likely most responsible for inspiring various fascia-specific interventions, and most often referred to when describing fascia&apos;s role in &quot;interrupting&quot; <a id="optimal" data-tip="1571" target="_blank" href="/glossary-term/optimal" class="glossary">optimal</a> motion. Carvalhais et al. demonstrated that <a id="tension" data-tip="1229" target="_blank" href="/glossary-term/tension" class="glossary">tension</a> may be transmitted through fascial sheaths to investing musculature, and Vleeming et al. has demonstrated the ability of fascia to transmit the force of multiple muscles to aid in joint stabilization (149, 173, 175).
Research also suggests the existence of myofibroblasts within the fascia, which may give the fascia the ability to contract. This ability is limited when compared to skeletal <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> tissue; however, the force generated was found to be significant enough to alter mechanics (in the lumbar spine) (150). It should also be noted that contraction in this study was very slow and in response to the antihistaminic substance, mepyramine (similar to smooth <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a>), and these cells do not respond to electricity, <a id="tension" data-tip="1229" target="_blank" href="/glossary-term/tension" class="glossary">tension</a>, or sympathetic <a id="hormone" data-tip="1268" target="_blank" href="/glossary-term/hormone" class="glossary">hormones</a>. Although these findings do not lend themselves to practical application, they do inspire more <a id="hypothesis" data-tip="1447" target="_blank" href="/glossary-term/hypothesis" class="glossary">hypotheses</a> regarding the importance and function of this previously ignored tissue.
<h4>Fascia as a Passive Tissue (Traditional Functions):</h4>
<ul>
 <li>Support</li>
 <li>Protect</li>
 <li>Store elastic energy</li>
 <li>Transmit force from <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> to bone</li>
</ul>
<h4>Fascia as an Active Medium of Communication</h4>
<ul>
 <li>Innervated with free <a id="nerve-cell" data-tip="1361" target="_blank" href="/glossary-term/nerve-cell" class="glossary">nerve</a> endings, Pacinian corpuscles, and Ruffini endings</li>
 <li>Arranged in layers that <a id="glide" data-tip="1815" target="_blank" href="/glossary-term/glide" class="glossary">slide</a> over one another</li>
 <li>May transmit <a id="tension" data-tip="1229" target="_blank" href="/glossary-term/tension" class="glossary">tension</a> between invested musculature</li>
 <li>May transmit the force of multiple muscles to aid in joint stabilization</li>
 <li>Fibroblasts may play a role in increasing <a id="tension" data-tip="1229" target="_blank" href="/glossary-term/tension" class="glossary">tension</a> in the fascia and altering mechanics.</li>
</ul>
A growing body of research has started to investigate the effect <a id="movement-impairment" data-tip="1575" target="_blank" href="/glossary-term/movement-impairment" class="glossary">movement impairment</a> has on fascial tissue, and what role fascial dysfunction may play in contributing to <a id="movement-impairment" data-tip="1575" target="_blank" href="/glossary-term/movement-impairment" class="glossary">movement impairment</a>. This statement by Schleip is a great example of the beginnings of an <a id="integration" data-tip="1472" target="_blank" href="/glossary-term/integration" class="glossary">integration</a> of these two fields, &quot;tonic muscles contain more perimysium and are therefore stiffer than phasic muscles&quot; (151). The terms, tonic and phasic refer to a categorization of muscles based on their roles in maintaining <a id="posture" data-tip="1658" target="_blank" href="/glossary-term/posture" class="glossary">posture</a> and/or contributing to <a id="posture" data-tip="1659" target="_blank" href="/glossary-term/posture" class="glossary">postural</a> dysfunction (1).
Fascia does seem to follow a predictable set of responses to excessive stress. This includes thickening, histochemical changes, decrease in tensile strength (increased risk of rupture), and the addition of disordered collagen fibers (156, 157, 161 - 165, 169 - 172). These consistent changes may have important implications for how these tissues should be addressed.

The crural (lower leg) fascia presents with a mean thickness of 924 &#x3BC;m (&#x3BC;m = micrometer = 1/1000 mm), and is composed of two or three layers of collagen fiber bundles with a mean thickness of 277.6 &#x3BC;m. A thin layer of loose <a id="connective-tissue-cell" data-tip="1368" target="_blank" href="/glossary-term/connective-tissue-cell" class="glossary">connective tissue</a>, with a mean thickness of 43 &#x3BC;m, usually separates the different layers. In each layer, a prevalent direction of the fibers is recognizable, forming angles of 80&#x2013;90&#xB0; to those in adjacent layers (146, 147). Surprisingly, elastin only exists at the borders of the crural fascia and in loose <a id="connective-tissue-cell" data-tip="1368" target="_blank" href="/glossary-term/connective-tissue-cell" class="glossary">connective tissue</a> and is nearly absent in the layers of overlapping deep fascia (146). This may imply that restrictions are not due to a loss of &quot;elasticity,&quot; but rather a movement between layers, or binding between layers that do not allow for the &quot;uncrimping&quot; of the wavy fascial sheaths. Although more research is needed, this <a id="hypothesis" data-tip="1446" target="_blank" href="/glossary-term/hypothesis" class="glossary">hypothesis</a> does seem to favor instrument-assisted soft tissue mobilization (IASTM), pin and stretch, and other myofascial techniques that create <a id="glide" data-tip="1817" target="_blank" href="/glossary-term/glide" class="glossary">shear</a> forces between layers of tissue. Treatment of the crural fascia with IASTM and Pin-and-Stretch techniques has proven effective in practice, especially relative to enhancing the carry-over of <a id="mobility" data-tip="1455" target="_blank" href="/glossary-term/mobility" class="glossary">mobility</a> gains.

<h4>Plantar Fascia</h4>
The plantar fascia is an important fascial structure, aiding in stabilization of the <a id="medial" data-tip="1568" target="_blank" href="/glossary-term/medial" class="glossary">medial</a> longitudinal arch of the foot, resisting pronation, and increasing the rigidity necessary for push-off during gait (via the &quot;windlass mechanism&quot;). The importance of this structure can be seen in the effect rupture/release of the plantar fascia has on the mechanics of the foot, generally resulting in pes planus (<a href="https://brookbushinstitute.com/video/overhead-squat-assessment-4-feet-flat-breakdown" target="_blank" rel="noopener">feet flatten</a>) (152, 153). The plantar fascia has been implicated as a source of injury/dysfunction, commonly resulting in complaints of pain around the <a id="medial" data-tip="1568" target="_blank" href="/glossary-term/medial" class="glossary">medial</a> tubercle of the calcaneus, generally worst with the first few steps upon waking, and commonly diagnosed as plantar fasciitis (154). This set of symptoms and diagnosis has been shown to be linked to altered biomechanics, including <a href="https://brookbushinstitute.com/video/overhead-squat-assessment-4-feet-flat-breakdown" target="_blank" rel="noopener">feet flatten</a> and a <a href="https://brookbushinstitute.com/video/dorsiflexion-goniometry" target="_blank" rel="noopener">loss of dorsiflexion</a> (admittedly, an assumption is being made that the <a href="https://brookbushinstitute.com/video/dorsiflexion-goniometry" target="_blank" rel="noopener">loss of dorsiflexion</a> is correlated with the increase in forefoot pressure in the studies cited) (155, 156). As mentioned above this dysfunction results in a thickening of the plantar fascia, a loss of <a id="extensibility-2" data-tip="1308" target="_blank" href="/glossary-term/extensibility-2" class="glossary">extensibility</a>, and perhaps an increased risk of rupture (weakening) (157, 158). It is important that these changes are carefully considered before interventions are selected. If a loss of <a id="extensibility-2" data-tip="1308" target="_blank" href="/glossary-term/extensibility-2" class="glossary">extensibility</a> is due to inflammation and being &quot;stuck&quot; in a lengthened position due to <a href="https://brookbushinstitute.com/video/overhead-squat-assessment-4-feet-flat-breakdown" target="_blank" rel="noopener">feet flatten</a> and a <a href="https://brookbushinstitute.com/video/dorsiflexion-goniometry" target="_blank" rel="noopener">loss of dorsiflexion</a>, rolling the bottom of the foot on a ball cannot be expected to have any long-term positive effect. Correction of biomechanics, reducing stress on the plantar fascia, and methods of reducing inflammation may be more pertinent means of addressing the issue.
<h4>Achilles Tendon</h4>
The Achilles tendon, being the tendon for our <a href="https://brookbushinstitute.com/article/gastrocnemius-plantaris" target="_blank" rel="noopener">gastrocnemius, plantaris</a>, and <a href="https://brookbushinstitute.com/article/soleus" target="_blank" rel="noopener">soleus</a>, plays a role in virtually all lower extremity motion, and therefore a role in LED. Although, as a tendon, this structure is inherently different than the crural fascia or plantar fascia, research on this structure may give us further clues regarding the maladaptive changes that occur to fascial structures. Further, we may be able to use the Achilles tendon as a <a id="model" data-tip="1469" target="_blank" href="/glossary-term/model" class="glossary">model</a> of tissue dysfunction occurring due to excessive tension; as mentioned above the <a href="https://brookbushinstitute.com/article/gastrocnemius-plantaris" target="_blank" rel="noopener">gastrocnemius, plantaris</a> and <a href="https://brookbushinstitute.com/article/soleus" target="_blank" rel="noopener">soleus</a> are commonly over-active. Research has correlated Achilles tendonitis/tendinopathy with changes in biomechanics, specifically when <a id="movement-impairment" data-tip="1575" target="_blank" href="/glossary-term/movement-impairment" class="glossary">movement impairment</a> is paired with high volume activity (159, 160). Again, research demonstrates the same pattern of fascial dysfunction in those with Achilles Tendinopathy, that is increased thickness, decreased tensile strength, and histochemical changes (161 - 165). Of particular interest, relative to a predictive <a id="model" data-tip="1469" target="_blank" href="/glossary-term/model" class="glossary">model</a> dysfunction, is a study that showed histochemical changes preceded Achilles tendon rupture (164). Achilles tendinopathy has benefited from research on exercise intervention, showing that eccentric exercise may be particularly beneficial (166, 167).

Based on the implications of new research suggesting that fascia may be a medium of communication, the iliotibial band (ITB) may aid in explaining relationships between the various muscles, ligaments, and bones it attaches to. Based on studies by Faircough et al. and Stecco et al. the ITB invests in the following (168, 169):
<ul>
 <li><a href="https://brookbushinstitute.com/article/gluteus-maximus" target="_blank" rel="noopener">Gluteus Maximus</a></li>
 <li><a href="https://brookbushinstitute.com/article/tensor-fascia-latae-tfl" target="_blank" rel="noopener">Tensor Fasciae Latae (TFL)</a></li>
 <li><a href="https://brookbushinstitute.com/article/quadriceps-vastus-muscles" target="_blank" rel="noopener">Vastus Lateralis</a></li>
 <li><a href="https://brookbushinstitute.com/article/quadriceps-vastus-muscles" target="_blank" rel="noopener">Biceps Femoris</a></li>
 <li>Iliac Spine</li>
 <li>Patellar tendon</li>
 <li><a href="https://brookbushinstitute.com/glossary/lateral/" target="_blank" rel="noopener">Lateral</a> collateral ligament (LCL)</li>
 <li><a href="https://brookbushinstitute.com/glossary/lateral/" target="_blank" rel="noopener">Lateral</a> intermuscular septum with a strong attachment to the <a href="https://brookbushinstitute.com/glossary/lateral/" target="_blank" rel="noopener">lateral</a> femoral condyle</li>
 <li><a href="https://brookbushinstitute.com/glossary/lateral/" target="_blank" rel="noopener">Lateral</a> patellar retinaculum</li>
 <li>Fascial slips to Gerdy&#x2019;s tubercle (just <a href="https://brookbushinstitute.com/glossary/inferior/" target="_blank" rel="noopener">inferior</a> to the <a href="https://brookbushinstitute.com/glossary/lateral/" target="_blank" rel="noopener">lateral</a> tibial plateau)</li>
 <li>Fibular head</li>
 <li><a href="https://brookbushinstitute.com/glossary/anterior/" target="_blank" rel="noopener">Anterior</a> tibiofibular ligament</li>
</ul>
This research is what inspired consideration of the <a href="https://brookbushinstitute.com/article/tensor-fascia-latae-tfl" target="_blank" rel="noopener">TFL</a>, <a href="https://brookbushinstitute.com/article/quadriceps-vastus-muscles" target="_blank" rel="noopener">vastus lateralis</a>, <a href="https://brookbushinstitute.com/article/quadriceps-vastus-muscles" target="_blank" rel="noopener">biceps femoris</a>, and ITB as a synergy of particular practical importance. The over-activity/increased <a id="tension" data-tip="1229" target="_blank" href="/glossary-term/tension" class="glossary">tension</a> of this synergy seems to be a primary contributor to the excessive tibial rotation noted in <a href="https://brookbushinstitute.com/video/overhead-squat-assessment-5-feet-turn-out-breakdown" target="_blank" rel="noopener">feet turn out</a> (and <a href="https://brookbushinstitute.com/video/overhead-squat-assessment-6-knees-bow-in-breakdown" target="_blank" rel="noopener">knees bow in</a>), and the inadequate <a id="anterior" data-tip="1566" target="_blank" href="/glossary-term/anterior" class="glossary">anterior</a> <a id="glide" data-tip="1598" target="_blank" href="/glossary-term/glide" class="glossary">glide</a> of the fibular head discussed later in <a id="arthrokinematics" data-tip="1859" target="_blank" href="/glossary-term/arthrokinematics" class="glossary">arthrokinematics</a>. Although the <a href="https://brookbushinstitute.com/article/tensor-fascia-latae-tfl" target="_blank" rel="noopener">TFL</a> and <a href="https://brookbushinstitute.com/article/quadriceps-vastus-muscles" target="_blank" rel="noopener">biceps femoris</a> are commonly considered to be external rotators of the tibia, the synergy establishes a rationale for why to <a id="release" data-tip="1249" target="_blank" href="/glossary-term/release" class="glossary">release</a> of <a href="https://brookbushinstitute.com/article/quadriceps-vastus-muscles" target="_blank" rel="noopener">vastus lateralis</a> <a id="trigger-point" data-tip="1634" target="_blank" href="/glossary-term/trigger-point" class="glossary">trigger points</a> (often mistakenly referred to as &quot;foam rolling the iliotibial band&quot;) may be effective in alleviating knee pain. The puzzling relationship related to the ITB is the one with the <a href="https://brookbushinstitute.com/article/gluteus-maximus" target="_blank" rel="noopener">Gluteus Maximus</a>. Unlike the other structures listed, this <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> is <a id="prone" data-tip="1561" target="_blank" href="/glossary-term/prone" class="glossary">prone</a> to under-activity. Hence, despite its potential to produce force, it cannot be a contributor to dysfunction/diagnoses that seem to be related to increased stress.
The ITB, like the other fascial structures discussed, is often considered as a source of dysfunction and pain. Further, we can note that many of the structures of the knee with investments into the ITB are often involved in diagnoses related to knee pain (patellar tendon and <a id="lateral" data-tip="1567" target="_blank" href="/glossary-term/lateral" class="glossary">lateral</a> retinaculum). Regardless of whether the diagnosis is &quot;runner&apos;s knee (patellar tendonitis, jumper&apos;s knee (iliotibial band syndrome), or patellofemoral malalignment (patellofemoral pain syndrome), the same histochemical markers and increased thickness of <a id="connective-tissue-cell" data-tip="1368" target="_blank" href="/glossary-term/connective-tissue-cell" class="glossary">connective tissue</a> seem to be present (169 - 172). It would be interesting to determine whether the same decreases in tissue strength noted in plantar fascia research (157, 158) and whether fascial dysfunction alone may result in changes in the activity of the muscles invested.
<img src="https://www.datocms-assets.com/25800/1649100748-treeposetflgluteusminimus.jpg" width="157" height="290" title="TFL and Iliotibial band (connecting fascia)" alt="TFL and Iliotibial band (connecting fascia)">

Several of the muscles discussed above, invest in and may increase <a id="tension" data-tip="1229" target="_blank" href="/glossary-term/tension" class="glossary">tension</a> in the sacrotuberous ligament. The <a href="https://brookbushinstitute.com/article/biceps-femoris" target="_blank" rel="noopener">biceps femoris</a> and <a href="https://brookbushinstitute.com/article/gluteus-maximus" target="_blank" rel="noopener">gluteus maximus</a> seem particularly adept at increasing <a id="tension" data-tip="1229" target="_blank" href="/glossary-term/tension" class="glossary">tension</a> in this structure (173, 176); however, the <a href="https://brookbushinstitute.com/article/piriformis" target="_blank" rel="noopener">piriformis</a>, <a href="https://brookbushinstitute.com/article/semitendinosus-and-semimembranosus" target="_blank" rel="noopener">semitendinosus, semimembranosus</a>, and <a href="https://brookbushinstitute.com/article/deep-rotators-of-the-hip" target="_blank" rel="noopener">obturator internus</a> have also been implicated due to their attachments (177). The Brookbush Institute most often considers the <a href="https://brookbushinstitute.com/article/adductors" target="_blank" rel="noopener">adductor magnus</a> as part of this group due to an attachment to the sacrotuberous ligament; however, there is a void in the literature regarding this <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a>. Of importance to the development of the LED <a id="model" data-tip="1469" target="_blank" href="/glossary-term/model" class="glossary">model</a> is the role these muscles have on stabilization and/or dysfunction of the sacroiliac joint (SIJ). Dysfunction of the SIJ is commonly cited as a source of patient complaints of low back pain. Several studies by Vleeming et al. have shown that contraction of the muscles mentioned can increase <a id="tension" data-tip="1229" target="_blank" href="/glossary-term/tension" class="glossary">tension</a> of the sacrotuberous ligament, and contribute to <a id="force-closure" data-tip="1448" target="_blank" href="/glossary-term/force-closure" class="glossary">force closure</a> of the SIJ (173 - 175). Further, increased <a id="tension" data-tip="1229" target="_blank" href="/glossary-term/tension" class="glossary">tension</a> via muscular contraction can resist <a id="nutation" data-tip="1213" target="_blank" href="/glossary-term/nutation" class="glossary">nutation</a> (175, 176), contributing to altered movement patterns and <a id="arthrokinematics" data-tip="1863" target="_blank" href="/glossary-term/arthrokinematics" class="glossary">arthrokinematic</a> <a id="dyskinesis" data-tip="1693" target="_blank" href="/glossary-term/dyskinesis" class="glossary">dyskinesis</a> of the lumbar spine, SIJ, pelvis, and potentially the hip via muscles crossing both the hip and SIJ. As mentioned above the <a href="https://brookbushinstitute.com/article/piriformis" target="_blank" rel="noopener">piriformis</a>, <a href="https://brookbushinstitute.com/article/biceps-femoris" target="_blank" rel="noopener">biceps femoris</a> and <a href="https://brookbushinstitute.com/article/adductors" target="_blank" rel="noopener">adductor magnus</a> are <a id="prone" data-tip="1561" target="_blank" href="/glossary-term/prone" class="glossary">prone</a> to over-activity, which may explain how cases of LED may result in low back pain.

Sacrotuberous Ligament

<ul>
 <li>Fascial dysfunction results in a predictable set of changes to the tissue (thickening, histochemical changes, decrease in tensile strength (increased risk of rupture), and the addition of disordered collagen fibers)</li>
 <li>Several pathologies/diagnoses related to LED are <a id="specificity" data-tip="1224" target="_blank" href="/glossary-term/specificity" class="glossary">specific</a> to fascial structures</li>
 <li>The crural fascia, fascia lata, and iliotibial band are layered, and therefore, may be a site of restriction due to an interruption of &quot;sliding layers&quot;</li>
 <li>The ITB may be a communicating medium for a synergy including the <a href="https://brookbushinstitute.com/article/tensor-fascia-latae-tfl" target="_blank" rel="noopener">TFL</a>, <a href="https://brookbushinstitute.com/article/quadriceps-vastus-muscles" target="_blank" rel="noopener">vastus lateralis</a>, and <a href="https://brookbushinstitute.com/article/quadriceps-vastus-muscles" target="_blank" rel="noopener">biceps femoris</a></li>
 <li>The sacrotuberous ligament may be a communicating medium for a synergy including <a href="https://brookbushinstitute.com/article/piriformis" target="_blank" rel="noopener">piriformis</a>, <a href="https://brookbushinstitute.com/article/deep-rotators-of-the-hip" target="_blank" rel="noopener">obturator internus</a>, <a href="https://brookbushinstitute.com/article/biceps-femoris" target="_blank" rel="noopener">biceps femoris</a>, and <a href="https://brookbushinstitute.com/article/adductors" target="_blank" rel="noopener">adductor magnus</a></li>
</ul>
Summary of Issues with &quot;An Introduction of Fascia into a Predictive <a id="model" data-tip="1469" target="_blank" href="/glossary-term/model" class="glossary">Model</a> of Dysfunction&quot;:
The research on fascia is likely the newest branch of research discussed in this article, and not surprisingly the most incomplete. It is my suggestion that fascia research is used to add to an understanding of related pathologies, and further used to hypothesize about myofascial synergies. Research on interventions <a id="specificity" data-tip="1224" target="_blank" href="/glossary-term/specificity" class="glossary">specific</a> to fascia is very sparse (covered in separate articles). Rather than use this information to add to the table constructed throughout this article, related fascial structures will remain a sub-category, and &quot;myofascial synergies&quot; will be grouped together in the table.
<img src="https://www.datocms-assets.com/25800/1649099506-posterior-oblique-subsystem.png" alt="Illustration of the Posterior Oblique Subsystem with Muscles Labeled">
<a id="posterior" data-tip="1565" target="_blank" href="/glossary-term/posterior" class="glossary">Posterior</a> Oblique Subsystem

Research leading to the development of <a id="hypothesis" data-tip="1447" target="_blank" href="/glossary-term/hypothesis" class="glossary">hypotheses</a> on myofascial synergies (also known as slings or subsystems, and similar to the serape effect) (5, 178, 179) has influenced how the Brookbush Institute selects core exercises and <a id="integration" data-tip="1473" target="_blank" href="/glossary-term/integration" class="glossary">integrated</a> movement patterns. It is our belief that research on these myofascial synergies is an important step toward investigating recruitment patterns as they occur; as opposed to looking at isolated structures without the perspective of their role in an <a id="integration" data-tip="1473" target="_blank" href="/glossary-term/integration" class="glossary">integrated</a> system. You may note that many of the references in this section are the same as those cited in previous sections. The redundancy is not purposeful but is evidence that the research in the muscular and fascial sections are related to the additional studies demonstrating synergistic behavior or force transfer between fascial sheaths that have been added to this section. As each subsystem is discussed in detail in separate articles, only a brief summary of <a id="relevance" data-tip="1505" target="_blank" href="/glossary-term/relevance" class="glossary">relevant</a> research, function, and hypothesized behavior relative to LED is given below.

<h4>Under-active <a href="https://brookbushinstitute.com/article/posterior-oblique-subsystem-pos" target="_blank" rel="noopener">Posterior Oblique Subsystem (POS)</a>:</h4>
<ul>
 <li><a href="https://brookbushinstitute.com/article/trapezius-muscle" target="_blank" rel="noopener">Lower Trapezius</a></li>
 <li><a href="https://brookbushinstitute.com/article/latissimus-dorsi" target="_blank" rel="noopener">Latissimus Dorsi</a></li>
 <li>Thoracolumbar Fascia</li>
 <li><a href="https://brookbushinstitute.com/article/gluteus-maximus" target="_blank" rel="noopener">Contralateral Gluteus Maximus</a></li>
 <li><a href="https://brookbushinstitute.com/courses" target="_blank" rel="noopener">Gluteus Medius</a></li>
</ul>
The muscles that comprise the <a href="https://brookbushinstitute.com/article/posterior-oblique-subsystem-pos" target="_blank" rel="noopener">POS</a> are the largest in the body. This subsystem plays a significant role in transferring force between lower and upper extremities, is involved in all pulling and rotational movement patterns (especially turning out), and eccentrically decelerates spinal flexion and rotation, as well as hip flexion, adduction, and internal rotation (<a href="https://brookbushinstitute.com/video/overhead-squat-assessment-6-knees-bow-in-breakdown" target="_blank" rel="noopener">knees bow in</a> and <a href="https://brookbushinstitute.com/video/overhead-squat-assessment-8-excessive-forward-lean" target="_blank" rel="noopener">excessive forward lean</a>).
Several studies have demonstrated the synergistic function of these muscles, force transfer between the <a href="https://brookbushinstitute.com/article/latissimus-dorsi" target="_blank" rel="noopener">latissimus dorsi</a> and <a href="https://brookbushinstitute.com/article/gluteus-maximus" target="_blank" rel="noopener">gluteus maximus</a> via the thoracolumbar fascia, and the contribution of the <a href="https://brookbushinstitute.com/article/posterior-oblique-subsystem-pos" target="_blank" rel="noopener">POS</a> to lumbar and sacroiliac joint stabilization (149, 178 - 185). These are larger muscles, and seemingly in congruence with the &quot;law of parsimony,&quot; appear to be recruited more as the intensity of exercise increases (184). At all intensities, the <a href="https://brookbushinstitute.com/article/posterior-oblique-subsystem-pos" target="_blank" rel="noopener">POS</a> must work in conjunction with the <a href="https://brookbushinstitute.com/article/intrinsic-stabilization-subsystem" target="_blank" rel="noopener">Intrinsic Stabilization Subsystem (ISS)</a> and <a href="https://brookbushinstitute.com/article/deep-longitudinal-subsystem" target="_blank" rel="noopener">Deep Longitudinal Subsystems (DLS)</a> (specifically the <a href="https://brookbushinstitute.com/article/biceps-femoris" target="_blank" rel="noopener">erector spinae</a>, <a href="https://brookbushinstitute.com/article/biceps-femoris" target="_blank" rel="noopener">Biceps Femoris</a>, and <a href="https://brookbushinstitute.com/article/multifidus" target="_blank" rel="noopener">multifidus</a> muscles (184, 185).
As mentioned above, under-activity of the <a href="https://brookbushinstitute.com/article/gluteus-maximus" target="_blank" rel="noopener">gluteus maximus</a> and <a href="https://brookbushinstitute.com/article/gluteus-maximus" target="_blank" rel="noopener">gluteus medius</a> has been correlated with pain and dysfunction of the low back, sacroiliac joint (SIJ), hip, knee, and ankle (23, 26, 28, 42, 49, 50, 52, 56, 57, 76, 77, 83, 129, 131), and most pertinent to practice, greater <a href="https://brookbushinstitute.com/article/gluteus-maximus" target="_blank" rel="noopener">gluteus maximus</a> strength has been correlated with better landing mechanics, running mechanics, and squat mechanics (23, 50, 52, 56, 57, 131). Note, the <a href="https://brookbushinstitute.com/article/latissimus-dorsi" target="_blank" rel="noopener">latissimus dorsi</a> and <a href="https://brookbushinstitute.com/article/trapezius-muscle" target="_blank" rel="noopener">lower trapezius</a> will be considered in the predictive <a id="model" data-tip="1469" target="_blank" href="/glossary-term/model" class="glossary">model</a> of <a href="https://brookbushinstitute.com/article/lumbo-pelvic-hip-complex-dysfunction-lphcd" target="_blank" rel="noopener">Lumbo Pelvic Hip Complex Dysfunction (LPHCD)</a>, as they do not have a direct influence on LED.
Based on this research, the function of the <a href="https://brookbushinstitute.com/article/posterior-oblique-subsystem-pos" target="_blank" rel="noopener">POS</a>, and the impairments noted in the LED <a id="model" data-tip="1469" target="_blank" href="/glossary-term/model" class="glossary">model</a>, it is our <a id="hypothesis" data-tip="1446" target="_blank" href="/glossary-term/hypothesis" class="glossary">hypothesis</a> that the system is <a id="prone" data-tip="1561" target="_blank" href="/glossary-term/prone" class="glossary">prone</a> to under-activity. The Brookbush Institute addresses this issue by making the <a href="https://brookbushinstitute.com/article/posterior-oblique-subsystem-pos" target="_blank" rel="noopener">POS</a> a focus during the selection of core exercise and <a id="integration" data-tip="1473" target="_blank" href="/glossary-term/integration" class="glossary">integrated</a> (whole-body) movement patterns. For example, an individual exhibiting LED may be progressed to a routine that includes <a href="https://brookbushinstitute.com/article/bridge-progression" target="_blank" rel="noopener">bridges</a> and <a href="https://brookbushinstitute.com/article/stability-progression-for-integrated-exercise" target="_blank" rel="noopener">legs with pull</a>.
<img src="https://www.datocms-assets.com/25800/1644265488-1632842654-posterior-oblique-sling.jpg" title="Posterior oblique subsystem (notice latissimus dorsi, thoracolumbar fascia and gluteus maximus)" alt="Posterior oblique subsystem (notice latissimus dorsi, thoracolumbar fascia and gluteus maximus)">

<h4>Over-active <a href="https://brookbushinstitute.com/article/anterior-oblique-subsystem-aos" target="_blank" rel="noopener">Anterior Oblique Subsystem (AOS)</a></h4>
<ul>
 <li><a href="https://brookbushinstitute.com/article/external-obliques" target="_blank" rel="noopener">External Obliques</a></li>
 <li><a href="https://brookbushinstitute.com/article/internal-obliques" target="_blank" rel="noopener">Internal Obliques</a></li>
 <li><a href="https://brookbushinstitute.com/article/muscular-anatomy" target="_blank" rel="noopener">Rectus Abdominis</a></li>
 <li>Abdominal Fascia/Linea Alba</li>
 <li><a href="https://brookbushinstitute.com/article/adductors" target="_blank" rel="noopener">Contralateral </a><a id="anterior" data-tip="1566" target="_blank" href="/glossary-term/anterior" class="glossary">Anterior</a> Adductors</li>
</ul>
The muscles that comprise the <a href="https://brookbushinstitute.com/article/anterior-oblique-subsystem-aos" target="_blank" rel="noopener">AOS</a> are also large but have far less mass than those in the <a href="https://brookbushinstitute.com/article/posterior-oblique-subsystem-pos" target="_blank" rel="noopener">POS</a>. This subsystem plays a significant role in transferring force between lower and upper extremities, is involved in all pushing and rotational movement patterns (especially turning in), and eccentrically decelerates spinal extension and rotation, as well as hip extension, abduction, and external rotation. Although a bit over-simplified, it may be worth considering this to be the anti-rotation/anti-extension subsystem, and a primary mechanism of defense against acute lumbar injuries. When this subsystem is over-active it may also contribute to hip flexion, adduction, and internal rotation (<a href="https://brookbushinstitute.com/video/overhead-squat-assessment-6-knees-bow-in-breakdown" target="_blank" rel="noopener">knees bow in</a> and <a href="https://brookbushinstitute.com/video/overhead-squat-assessment-8-excessive-forward-lean" target="_blank" rel="noopener">excessive forward lean</a>).
Several publications indicate that there may be a relationship between the sacroiliac joint, pubic symphysis, <a id="anterior" data-tip="1566" target="_blank" href="/glossary-term/anterior" class="glossary">anterior</a> abdominal activity, and <a href="https://brookbushinstitute.com/article/adductors" target="_blank" rel="noopener">adductor</a> activity (77, 180, 186 - 188). Discussing this relationship based on research findings is a bit complicated, but if considered only from the perspective of how the <a href="https://brookbushinstitute.com/article/adductors" target="_blank" rel="noopener">adductors</a> are involved, the relationship seems to be supported by only a couple of studies. In a study by Snijders et al., it was found that crossing the legs decreased the activity of the <a href="https://brookbushinstitute.com/article/internal-obliques" target="_blank" rel="noopener">internal obliques</a> (188). It is hypothesized that crossing the legs altered adductor activity and force imparted on the pubis, resulting in a reduction in the activity of the <a href="https://brookbushinstitute.com/article/internal-obliques" target="_blank" rel="noopener">internal obliques</a>, an important <a id="stabilizers" data-tip="1653" target="_blank" href="/glossary-term/stabilizers" class="glossary">stabilizer</a> of the pubis, sacroiliac joint, and lumbar spine. Further, <a href="https://brookbushinstitute.com/article/adductors" target="_blank" rel="noopener">adductor</a> activity remained unchanged (along with <a href="https://brookbushinstitute.com/article/tensor-fascia-latae-tfl" target="_blank" rel="noopener">TFL</a>, <a href="https://brookbushinstitute.com/article/biceps-femoris" target="_blank" rel="noopener">biceps femoris</a>) while <a href="https://brookbushinstitute.com/article/internal-obliques" target="_blank" rel="noopener">internal oblique</a>, <a href="https://brookbushinstitute.com/article/multifidus" target="_blank" rel="noopener">lumbar multifidus</a>, and <a href="https://brookbushinstitute.com/article/gluteus-maximus" target="_blank" rel="noopener">gluteus maximus</a> activity decreased or fired later in those with sacroiliac joint pain (77). This could be viewed as a relative increase in <a href="https://brookbushinstitute.com/article/adductors" target="_blank" rel="noopener">adductor</a> activity (along with <a href="https://brookbushinstitute.com/article/tensor-fascia-latae-tfl" target="_blank" rel="noopener">TFL</a> and <a href="https://brookbushinstitute.com/article/biceps-femoris" target="_blank" rel="noopener">biceps femoris</a>). The simplest explanation for this relationship may be the fascial continuity between the superficial abdominal fascia, fascia latae, and/or adductor tendons, with the strongest continuity existing between the <a href="https://brookbushinstitute.com/article/muscular-anatomy" target="_blank" rel="noopener">rectus abdominis</a> and <a href="https://brookbushinstitute.com/article/adductors" target="_blank" rel="noopener">adductor longus</a> tendons (see image below). Note, the activity of the <a href="https://brookbushinstitute.com/article/external-obliques" target="_blank" rel="noopener">external obliques</a>, <a href="https://brookbushinstitute.com/article/internal-obliques" target="_blank" rel="noopener">internal obliques</a>, and <a href="https://brookbushinstitute.com/article/muscular-anatomy" target="_blank" rel="noopener">rectus abdominis</a> will be considered further in the predictive <a id="model" data-tip="1469" target="_blank" href="/glossary-term/model" class="glossary">model</a> of <a href="https://brookbushinstitute.com/article/lumbo-pelvic-hip-complex-dysfunction-lphcd" target="_blank" rel="noopener">Lumbo Pelvic Hip Complex Dysfunction (LPHCD)</a>
As mentioned above, over-activity of the <a href="https://brookbushinstitute.com/article/adductors" target="_blank" rel="noopener">adductors</a> has been correlated with <a href="https://brookbushinstitute.com/video/overhead-squat-assessment-6-knees-bow-in-breakdown" target="_blank" rel="noopener">knees bow in</a> (23, 26, 28), and it may be presumed based on function, that an over-active <a href="https://brookbushinstitute.com/article/anterior-oblique-subsystem-aos" target="_blank" rel="noopener">AOS</a> would contribute to an <a href="https://brookbushinstitute.com/video/overhead-squat-assessment-8-excessive-forward-lean" target="_blank" rel="noopener">excessive forward lean</a>. Based on this, our <a id="hypothesis" data-tip="1446" target="_blank" href="/glossary-term/hypothesis" class="glossary">hypothesis</a> is that this system is <a id="prone" data-tip="1561" target="_blank" href="/glossary-term/prone" class="glossary">prone</a> to over-activity. The Brookbush Institute addresses this issue with &quot;release and avoid.&quot; That is, the <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> and fascial structures that can be <a id="release" data-tip="1253" target="_blank" href="/glossary-term/release" class="glossary">released</a> are addressed, and exercise that places emphasis on the <a href="https://brookbushinstitute.com/article/anterior-oblique-subsystem-aos" target="_blank" rel="noopener">AOS</a> is avoided until movement quality improves, for example, <a href="https://brookbushinstitute.com/article/plank-progression" target="_blank" rel="noopener">planks</a>, <a href="https://brookbushinstitute.com/article/crunch-progression" target="_blank" rel="noopener">crunches</a>, leg raises, etc...
<img src="https://www.datocms-assets.com/25800/1649099568-aos.jpg" alt="Muscles that attach to the pubis including Fascial Attachment between Rectus Abdominis and Adductor Tendons">
Fascial Attachment between Rectus Abdominis and Adductor Tendons

<h4>Over-active <a href="https://brookbushinstitute.com/article/deep-longitudinal-subsystem" target="_blank" rel="noopener">Deep Longitudinal Subsystem (DLS)</a></h4>
<ul>
 <li><a href="https://brookbushinstitute.com/article/erector-spinae" target="_blank" rel="noopener">Erector Spinae</a></li>
 <li>Sacrotuberous Ligament</li>
 <li><a href="https://brookbushinstitute.com/article/biceps-femoris" target="_blank" rel="noopener">Biceps Femoris</a></li>
 <li>Head of Fibula</li>
 <li><a href="https://brookbushinstitute.com/article/fibularis-muscles" target="_blank" rel="noopener">Fibularis Longus</a> (aka Peroneals)</li>
</ul>
It is likely easiest to consider the function of the <a href="https://brookbushinstitute.com/article/deep-longitudinal-subsystem" target="_blank" rel="noopener">DLS</a> relative to gait. <a href="https://brookbushinstitute.com/glossary/optimal/" target="_blank" rel="noopener">Optimally</a>, the <a href="https://brookbushinstitute.com/article/deep-longitudinal-subsystem" target="_blank" rel="noopener">DLS</a> would eccentrically decelerate hip flexion, knee extension, and supination during late-phase swing, stabilize the sacroiliac joint (SIJ) and arch of the foot during heel strike, and aid in propulsion during early stance and push-off phases. Further, this myofascial synergy may act as a proprioceptive mechanism to relay information about <a id="ground-reaction-force" data-tip="1397" target="_blank" href="/glossary-term/ground-reaction-force" class="glossary">ground reaction forces</a> upon heel strike, ensure adequate but not excessive pronation, and as a product of the proprioceptive of information relayed to the CNS &#x2013; result in <a href="https://brookbushinstitute.com/glossary/optimal/" target="_blank" rel="noopener">optimal</a> recruitment of <a href="https://brookbushinstitute.com/glossary/prime-mover/" target="_blank" rel="noopener">prime movers</a> during mid-stance and push-off.
The synergistic relationship or at least a similar recruitment pattern noted between the <a href="https://brookbushinstitute.com/article/erector-spinae" target="_blank" rel="noopener">erector spinae</a> and <a href="https://brookbushinstitute.com/article/biceps-femoris" target="_blank" rel="noopener">biceps femoris</a> has been well documented during the push-off phase of gait. It may be important to note that this synergy also plays a role in other extension-type exercises, for example, a <a href="https://brookbushinstitute.com/article/tva" target="_blank" rel="noopener">quadruped with opposite arm/leg raise</a> and reverse-hypers (185, 189). Pertinent to LED, several studies show a trend toward earlier onset and increased activity of <a href="https://brookbushinstitute.com/article/erector-spinae" target="_blank" rel="noopener">erector spinae</a> and <a href="https://brookbushinstitute.com/article/biceps-femoris" target="_blank" rel="noopener">biceps femoris</a> in those with low back pain (192-193). As mentioned earlier, the increased activity of <a href="https://brookbushinstitute.com/article/erector-spinae" target="_blank" rel="noopener">erector spinae</a> and <a href="https://brookbushinstitute.com/article/biceps-femoris" target="_blank" rel="noopener">biceps femoris</a> is often paired with a reduction in <a href="https://brookbushinstitute.com/article/gluteus-maximus" target="_blank" rel="noopener">gluteus maximus</a> activity (<a href="https://brookbushinstitute.com/article/posterior-oblique-subsystem-pos" target="_blank" rel="noopener">POS</a> activity) (76-78). Leinonen et al, demonstrated this relationship precisely, showing earlier and increased activity of the <a href="https://brookbushinstitute.com/article/erector-spinae" target="_blank" rel="noopener">erector spinae</a> and <a href="https://brookbushinstitute.com/article/biceps-femoris" target="_blank" rel="noopener">biceps femoris</a> and a reduction in <a href="https://brookbushinstitute.com/article/gluteus-maximus" target="_blank" rel="noopener">gluteus maximus</a> activity during gait in those with low back pain (192). If the synergy does arise from fascial <a id="integration" data-tip="1472" target="_blank" href="/glossary-term/integration" class="glossary">integration</a>, it is likely through the complex network of fascia and ligaments of the lumbosacral region. Specifically, Vleeming et al. showed that the <a href="https://brookbushinstitute.com/article/erector-spinae" target="_blank" rel="noopener">erector spinae</a> and <a href="https://brookbushinstitute.com/article/biceps-femoris" target="_blank" rel="noopener">biceps femoris</a> contribute to <a id="force-closure" data-tip="1448" target="_blank" href="/glossary-term/force-closure" class="glossary">force closure</a> of the SIJ via the thoracolumbar fascia and sacrotuberous ligaments (190), and van Wingerden et al. demonstrated that &quot;Tension in the long <a id="dorsal" data-tip="1554" target="_blank" href="/glossary-term/dorsal" class="glossary">dorsal</a> sacroiliac ligament increased during loading of the <a id="ipsilateral" data-tip="1550" target="_blank" href="/glossary-term/ipsilateral" class="glossary">ipsilateral</a> sacrotuberous ligament and <a href="https://brookbushinstitute.com/article/erector-spinae" target="_blank" rel="noopener">erector spinae</a> <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> (191).&quot;
As mentioned earlier, several studies by Vleeming et al. have shown that contraction of the <a href="https://brookbushinstitute.com/article/biceps-femoris" target="_blank" rel="noopener">biceps femoris</a> can increase <a id="tension" data-tip="1229" target="_blank" href="/glossary-term/tension" class="glossary">tension</a> of the sacrotuberous ligament, contribute to <a id="force-closure" data-tip="1448" target="_blank" href="/glossary-term/force-closure" class="glossary">force closure</a> of the SIJ, and this increased <a id="tension" data-tip="1229" target="_blank" href="/glossary-term/tension" class="glossary">tension</a> may resist <a id="nutation" data-tip="1213" target="_blank" href="/glossary-term/nutation" class="glossary">nutation</a> (173 - 176). One of the primary functions of this myofascial synergy may be to stabilize the SIJ during heel strike to ensure a stable &quot;platform&quot; from which the <a href="https://brookbushinstitute.com/article/gluteus-maximus" target="_blank" rel="noopener">gluteus maximus</a> may generate force. Relative to LED, it is our <a id="hypothesis" data-tip="1446" target="_blank" href="/glossary-term/hypothesis" class="glossary">hypothesis</a> that over-activity of the <a href="https://brookbushinstitute.com/article/deep-longitudinal-subsystem" target="_blank" rel="noopener">DLS</a> (<a id="synergistic-dominance" data-tip="1643" target="_blank" href="/glossary-term/synergistic-dominance" class="glossary">synergistic dominance</a> for an inhibited <a href="https://brookbushinstitute.com/article/posterior-oblique-subsystem-pos" target="_blank" rel="noopener">POS</a>) may explain the relationship between LED. SIJ stiffness and <a href="https://brookbushinstitute.com/article/sacroiliac-joint-motion-and-predictive-model-of-dysfunction" target="_blank" rel="noopener">Lumbosacral Dysfunction (LSD)</a>, noted clinically.
The last connection to be made in this synergy is between the <a href="https://brookbushinstitute.com/article/biceps-femoris" target="_blank" rel="noopener">biceps femoris</a> and the <a href="https://brookbushinstitute.com/article/fibularis-muscles" target="_blank" rel="noopener">fibularis</a> muscles. The most obvious connections are anatomical connections, as both the <a href="https://brookbushinstitute.com/article/biceps-femoris" target="_blank" rel="noopener">biceps femoris</a> and the <a href="https://brookbushinstitute.com/article/fibularis-muscles" target="_blank" rel="noopener">fibularis</a> muscles insert on the fibular head. Further, the iliotibial band (ITB) invests in the fibular head, the <a href="https://brookbushinstitute.com/article/biceps-femoris" target="_blank" rel="noopener">biceps femoris</a> via the <a id="lateral" data-tip="1567" target="_blank" href="/glossary-term/lateral" class="glossary">lateral</a> intermuscular septum and continues into and over the <a href="https://brookbushinstitute.com/article/fibularis-muscles" target="_blank" rel="noopener">fibularis</a> muscles with a more expansive attachment into the <a id="anterior" data-tip="1566" target="_blank" href="/glossary-term/anterior" class="glossary">anterior</a> tibiofibular ligament (often continuous with the <a href="https://brookbushinstitute.com/article/biceps-femoris" target="_blank" rel="noopener">biceps femoris</a> tendon) and crural fascia (168, 169, 194). Note, consideration of the iliotibial band may implicate a relationship between the DLS and a myofascial synergy noted earlier that included the ITB, <a href="https://brookbushinstitute.com/article/tensor-fascia-latae-tfl" target="_blank" rel="noopener">TFL</a>, and <a href="https://brookbushinstitute.com/article/quadriceps-vastus-muscles" target="_blank" rel="noopener">vastus lateralis</a>. Although no further research examining <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> activity between the <a href="https://brookbushinstitute.com/article/biceps-femoris" target="_blank" rel="noopener">biceps femoris</a> and the <a href="https://brookbushinstitute.com/article/fibularis-muscles" target="_blank" rel="noopener">fibularis</a> muscles could be located, an <a id="arthrokinematics" data-tip="1863" target="_blank" href="/glossary-term/arthrokinematics" class="glossary">arthrokinematic</a> relationship may also exist. Over-activity of the <a href="https://brookbushinstitute.com/article/biceps-femoris" target="_blank" rel="noopener">biceps femoris</a> (along with muscles investing in the ITB) would result in an excessive <a id="posterior" data-tip="1565" target="_blank" href="/glossary-term/posterior" class="glossary">posterior</a> <a id="glide" data-tip="1598" target="_blank" href="/glossary-term/glide" class="glossary">glide</a> of the <a id="proximal" data-tip="1564" target="_blank" href="/glossary-term/proximal" class="glossary">proximal</a> <a href="https://brookbushinstitute.com/article/ankle-joint-talocrural-subtalor-tibiofibular-joints" target="_blank" rel="noopener">tibiofibular joint</a>. The tendons of the <a href="https://brookbushinstitute.com/article/fibularis-muscles" target="_blank" rel="noopener">fibularis</a> muscles pass behind the <a id="lateral" data-tip="1567" target="_blank" href="/glossary-term/lateral" class="glossary">lateral</a> malleolus in a groove and may be able to <a id="glide" data-tip="1598" target="_blank" href="/glossary-term/glide" class="glossary">glide</a> the <a id="distal" data-tip="1563" target="_blank" href="/glossary-term/distal" class="glossary">distal</a> <a href="https://brookbushinstitute.com/article/ankle-joint-talocrural-subtalor-tibiofibular-joints" target="_blank" rel="noopener">tibiofibular joint</a> anteriorly. It has been hypothesized that the <a href="https://brookbushinstitute.com/article/ankle-joint-talocrural-subtalor-tibiofibular-joints" target="_blank" rel="noopener">tibiofibular joints</a> (<a id="distal" data-tip="1563" target="_blank" href="/glossary-term/distal" class="glossary">distal</a> and <a id="proximal" data-tip="1564" target="_blank" href="/glossary-term/proximal" class="glossary">proximal</a>) move in opposition to one another due to the fiber arrangement of the interosseous membrane. That is, <a id="posterior" data-tip="1565" target="_blank" href="/glossary-term/posterior" class="glossary">posterior</a> <a id="glide" data-tip="1598" target="_blank" href="/glossary-term/glide" class="glossary">glide</a> of one will result in an <a id="anterior" data-tip="1566" target="_blank" href="/glossary-term/anterior" class="glossary">anterior</a> <a id="glide" data-tip="1598" target="_blank" href="/glossary-term/glide" class="glossary">glide</a> of the other. As both the <a href="https://brookbushinstitute.com/article/biceps-femoris" target="_blank" rel="noopener">biceps femoris</a> and the <a href="https://brookbushinstitute.com/article/fibularis-muscles" target="_blank" rel="noopener">fibularis</a> muscles are <a id="prone" data-tip="1561" target="_blank" href="/glossary-term/prone" class="glossary">prone</a> to over-activity, the motion of the <a href="https://brookbushinstitute.com/article/ankle-joint-talocrural-subtalor-tibiofibular-joints" target="_blank" rel="noopener">tibiofibular joints</a> may add to this synergistic relationship.
Based on this research, the function of the <a href="https://brookbushinstitute.com/article/deep-longitudinal-subsystem" target="_blank" rel="noopener">DLS</a>, and the impairments noted in the LED <a id="model" data-tip="1469" target="_blank" href="/glossary-term/model" class="glossary">model</a>, it is our <a id="hypothesis" data-tip="1446" target="_blank" href="/glossary-term/hypothesis" class="glossary">hypothesis</a> that this synergy is <a id="prone" data-tip="1561" target="_blank" href="/glossary-term/prone" class="glossary">prone</a> to over-activity. The Brookbush Institute addresses this issue with &quot;release and avoid.&quot; That is, the <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> and fascial structures that can be <a id="release" data-tip="1253" target="_blank" href="/glossary-term/release" class="glossary">released</a> are addressed, and exercise that places emphasis on the <a href="https://brookbushinstitute.com/article/deep-longitudinal-subsystem" target="_blank" rel="noopener">DLS</a> is avoided until movement quality improves, for example, leg curls, back extensions, etc...

<h4>Summary of Findings:</h4>
<ul>
 <li>Research <a id="specificity" data-tip="1224" target="_blank" href="/glossary-term/specificity" class="glossary">specific</a> to myofascial synergy adds to our understanding of how groups of muscles (synergies) may be recruited, and how the force they generate may be summated to aid in the stabilization of a joint and/or multi-joint motion.</li>
 <li>The relationships implied by research related to myofascial synergies reinforce the groupings (long, short, overactive, underactive, dysfunction) suggested in the &quot;Evidence-based Muscular Model&quot; and &quot;Introduction of Fascia&#x2026;&quot; sections.</li>
 <li>The <a href="https://brookbushinstitute.com/article/posterior-oblique-subsystem-pos" target="_blank" rel="noopener">POS</a> has a propensity toward under-activity.</li>
 <li>The <a href="https://brookbushinstitute.com/article/anterior-oblique-subsystem-aos" target="_blank" rel="noopener">AOS</a>, although important for stabilizing the pelvic girdle, has a propensity toward over-activity in those exhibiting LED.</li>
 <li>The <a href="https://brookbushinstitute.com/article/deep-longitudinal-subsystem" target="_blank" rel="noopener">DLS</a> has a propensity to become <a id="synergistic-dominance" data-tip="1649" target="_blank" href="/glossary-term/synergistic-dominance" class="glossary">synergistically dominant</a> for an inhibited/under-active <a href="https://brookbushinstitute.com/article/posterior-oblique-subsystem-pos" target="_blank" rel="noopener">POS</a>.</li>
 <li>The relationship between the <a href="https://brookbushinstitute.com/article/posterior-oblique-subsystem-pos" target="_blank" rel="noopener">POS</a> and <a href="https://brookbushinstitute.com/article/deep-longitudinal-subsystem" target="_blank" rel="noopener">DLS</a> may have important implications for SIJ and lumbar spine dysfunction, and link these <a id="movement-impairment" data-tip="1579" target="_blank" href="/glossary-term/movement-impairment" class="glossary">dysfunctions</a> to LED.</li>
</ul>
<table>
 <tbody>
 <tr>
 <td colspan="4" width="779">
 <h3>Lower Extremity Dysfunction based on Myofascial Research</h3>
 </td>
 </tr>
 <tr>
 <td colspan="2" width="390">Short</td>
 <td colspan="2" width="390">Long</td>
 </tr>
 <tr>
 <td width="195">Ankle Plantar Flexion (Loss of Dorsiflexion)</td>
 <td width="195">
 <ul>
 <li><a href="https://brookbushinstitute.com/article/gastrocnemius-plantaris" target="_blank" rel="noopener">Gastrocnemius and Plantaris</a></li>
 <li><a href="https://brookbushinstitute.com/article/soleus" target="_blank" rel="noopener">Soleus</a></li>
 </ul>
 </td>
 <td width="195">Ankle Dorsiflexion</td>
 <td width="195">
 <ul>
 <li><a href="https://brookbushinstitute.com/article/tibialis-anterior" target="_blank" rel="noopener">Tibialis Anterior</a></li>
 </ul>
 </td>
 </tr>
 <tr>
 <td width="195">Ankle Eversion</td>
 <td width="195">
 <ul>
 <li><a href="https://brookbushinstitute.com/article/fibularis-muscles" target="_blank" rel="noopener">Fibularis Longus and Fibularis Brevis</a></li>
 <li><a href="https://brookbushinstitute.com/article/gastrocnemius-plantaris" target="_blank" rel="noopener">Gastrocnemius</a></li>
 <li><a href="https://brookbushinstitute.com/article/extensor-hallucis-longus-and-extensor-digitorum-longus-fibularis-tertius" target="_blank" rel="noopener">Extensor Digitorum Longus</a></li>
 </ul>
 </td>
 <td width="195">Ankle Inversion</td>
 <td width="195">
 <ul>
 <li><a href="https://brookbushinstitute.com/article/tibialis-anterior" target="_blank" rel="noopener">Tibialis Anterior</a></li>
 <li><a href="https://brookbushinstitute.com/article/tibialis-posterior" target="_blank" rel="noopener">Tibialis Posterior</a></li>
 <li><a href="https://brookbushinstitute.com/article/flexor-hallucis-longus-and-flexor-digitorum-longus" target="_blank" rel="noopener">Flexor Hallucis Longus and Flexor Digitorum Longus</a></li>
 </ul>
 </td>
 </tr>
 <tr>
 <td width="195">Tibia External Rotation</td>
 <td width="195">
 <ul>
 <li><a href="https://brookbushinstitute.com/article/biceps-femoris" target="_blank" rel="noopener">Biceps Femoris</a></li>
 <li><a href="https://brookbushinstitute.com/article/tensor-fascia-latae-tfl" target="_blank" rel="noopener">Tensor Fascia Latae</a></li>
 <li><a href="https://brookbushinstitute.com/article/quadriceps-vastus-muscles" target="_blank" rel="noopener">Vastus Lateralis</a></li>
 <li><a href="https://brookbushinstitute.com/article/rectus-femoris" target="_blank" rel="noopener">Rectus Femoris</a></li>
 <li><a href="https://brookbushinstitute.com/article/sartorius" target="_blank" rel="noopener">Sartorius</a></li>
 </ul>
 </td>
 <td width="195">Tibia Internal Rotation</td>
 <td width="195">
 <ul>
 <li><a href="https://brookbushinstitute.com/article/adductors" target="_blank" rel="noopener">Gracilis</a></li>
 <li><a href="https://brookbushinstitute.com/article/semitendinosus-and-semimembranosus" target="_blank" rel="noopener">Semitendinosus &amp; Semimembranosus</a></li>
 <li><a href="https://brookbushinstitute.com/article/anatomy-articles/muscular-anatomy/popliteus/" target="_blank" rel="noopener">Popliteus</a>
 
 </li>
 <li><a href="https://brookbushinstitute.com/article/quadriceps-vastus-muscles" target="_blank" rel="noopener">Vastus Medialis Obliquus</a></li>
 </ul>
 </td>
 </tr>
 <tr>
 <td width="195">Hip Internal Rotation</td>
 <td width="195">
 <ul>
 <li><a href="https://brookbushinstitute.com/article/tensor-fascia-latae-tfl" target="_blank" rel="noopener">Tensor Fascia Latae</a></li>
 <li><a href="https://brookbushinstitute.com/article/gluteus-minimus" target="_blank" rel="noopener">Gluteus Minimus</a></li>
 <li><a href="https://brookbushinstitute.com/article/adductors" target="_blank" rel="noopener">Anterior Adductors</a></li>
 </ul>
 </td>
 <td width="195">Hip External Rotation</td>
 <td width="195">
 <ul>
 <li><a href="https://brookbushinstitute.com/article/gluteus-medius" target="_blank" rel="noopener">Gluteus Medius</a>,</li>
 <li><a href="https://brookbushinstitute.com/article/gluteus-maximus" target="_blank" rel="noopener">Gluteus Maximus</a></li>
 <li><a href="https://brookbushinstitute.com/article/piriformis" target="_blank" rel="noopener">Piriformis</a></li>
 <li><a href="https://brookbushinstitute.com/article/deep-rotators-of-the-hip" target="_blank" rel="noopener">Deep Rotators of the Hip</a></li>
 <li><a href="https://brookbushinstitute.com/article/biceps-femoris" target="_blank" rel="noopener">Biceps Femoris</a></li>
 <li><a href="https://brookbushinstitute.com/article/adductors" target="_blank" rel="noopener">Adductor Magnus</a></li>
 </ul>
 </td>
 </tr>
 <tr>
 <td width="195">Hip Flexion</td>
 <td width="195">
 <ul>
 <li><a href="https://brookbushinstitute.com/article/tensor-fascia-latae-tfl" target="_blank" rel="noopener">Tensor Fascia Latae</a></li>
 <li><a href="https://brookbushinstitute.com/article/adductors" target="_blank" rel="noopener">Anterior Adductors</a></li>
 <li><a href="https://brookbushinstitute.com/article/gluteus-minimus" target="_blank" rel="noopener">Gluteus Minimus</a></li>
 <li><a href="https://brookbushinstitute.com/article/psoas" target="_blank" rel="noopener">Psoas</a></li>
 <li><a href="https://brookbushinstitute.com/article/iliacus" target="_blank" rel="noopener">Iliacus</a></li>
 <li><a href="https://brookbushinstitute.com/article/rectus-femoris" target="_blank" rel="noopener">Rectus Femoris</a></li>
 </ul>
 </td>
 <td width="195">Hip Extension</td>
 <td width="195">
 <ul>
 <li><a href="https://brookbushinstitute.com/article/gluteus-medius" target="_blank" rel="noopener">Gluteus Medius</a></li>
 <li><a href="https://brookbushinstitute.com/article/gluteus-maximus" target="_blank" rel="noopener">Gluteus Maximus</a></li>
 <li><a href="https://brookbushinstitute.com/article/semitendinosus-and-semimembranosus" target="_blank" rel="noopener">Semitendinosus &amp; Semimembranosus</a></li>
 <li><a href="https://brookbushinstitute.com/article/biceps-femoris" target="_blank" rel="noopener">Biceps Femoris</a></li>
 </ul>
 </td>
 </tr>
 <tr>
 <td width="195">Over-active Myofascial Synergy</td>
 <td width="195">
 <ul>
 <li><a href="https://brookbushinstitute.com/article/deep-longitudinal-subsystem" target="_blank" rel="noopener">Deep Longitudinal Synergy (DLS)</a></li>
 <li><a href="https://brookbushinstitute.com/article/anterior-oblique-subsystem-aos" target="_blank" rel="noopener">Anterior Oblique Synergy (AOS)</a></li>
 </ul>
 </td>
 <td width="195">Under-active Myofascial Synergy</td>
 <td width="195">
 <ul>
 <li><a href="https://brookbushinstitute.com/article/posterior-oblique-subsystem-pos" target="_blank" rel="noopener">Posterior Oblique Synergy (POS)</a></li>
 </ul>
 </td>
 </tr>
 </tbody>
</table>
Summary of Issues with Myofascial Synergies:
<ul>
 <li>There has been very little evidence to <a id="base-of-support" data-tip="1197" target="_blank" href="/glossary-term/base-of-support" class="glossary">support</a> &quot;myofascial synergy <a id="specificity" data-tip="1224" target="_blank" href="/glossary-term/specificity" class="glossary">specific</a> interventions.&quot;</li>
 <li>How the <a href="https://brookbushinstitute.com/article/adductors" target="_blank" rel="noopener">adductors</a> behave relative to the recruitment of the <a href="https://brookbushinstitute.com/article/anterior-oblique-subsystem-aos" target="_blank" rel="noopener">AOS</a> is loosely implied by the currently available research, but not well defined.</li>
 <li>Studies investigating the relationship between the <a href="https://brookbushinstitute.com/article/biceps-femoris" target="_blank" rel="noopener">biceps femoris</a> and the <a href="https://brookbushinstitute.com/article/fibularis-muscles" target="_blank" rel="noopener">fibularis</a> muscles have yet to be published.</li>
</ul>
<img src="https://www.datocms-assets.com/25800/1649099636-screen-shot-2016-12-26-at-1-48-28-pm.png" alt="The Brookbush Institute recommends posterior-to-anterior self-administered hip joint mobilizations for individuals with suspected arthrokinematic dysfunction.">
The Brookbush Institute recommends posterior-to-anterior self-administered hip joint mobilizations for individuals with suspected <a id="arthrokinematics" data-tip="1863" target="_blank" href="/glossary-term/arthrokinematics" class="glossary">arthrokinematic</a> dysfunction.

As mentioned earlier, if various approaches are effective for different reasons (as implied by the varied intents), then an <a id="integration" data-tip="1473" target="_blank" href="/glossary-term/integration" class="glossary">integrated</a> approach may have the potential to improve outcomes by addition of the various benefits. Based on this premise, a weakness of the previous analyses (Traditional, <a id="osteokinematic-motion" data-tip="1881" target="_blank" href="/glossary-term/osteokinematic-motion" class="glossary">Osteokinematic</a>, Muscular, Fascial and Myofascial Synergies) is a failure to consider the effectiveness of well-established joint-based approaches. For example, osteopathic medicine, chiropractic, Cyriax/Maitland, Mulligan, Paris, etc.. Although measuring the small amounts of motion associated with <a id="arthrokinematics" data-tip="1859" target="_blank" href="/glossary-term/arthrokinematics" class="glossary">arthrokinematics</a> poses a considerable challenge for researchers, the body of research is growing. Further, several studies have noted a change in muscular activity as a result of joint mobilizations (213, 229, 241, 242). It is the assertion of the Brookbush Institute, that evidence of joint mobilizations affecting <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> activity supports the premise of a <a id="holism" data-tip="1463" target="_blank" href="/glossary-term/holism" class="glossary">holistic</a> system of human movement and an <a id="integration" data-tip="1473" target="_blank" href="/glossary-term/integration" class="glossary">integrated</a> approach, as mentioned at the beginning of this article. In this &#x201C;level of analysis,&#x201D; an attempt is made to aggregate all <a href="https://brookbushinstitute.com/glossary/relevance/" target="_blank" rel="noopener">relevant</a> research on altered <a id="arthrokinematics" data-tip="1859" target="_blank" href="/glossary-term/arthrokinematics" class="glossary">arthrokinematics</a> associated with impairments of the lower extremity (LED).

<h4><a href="https://brookbushinstitute.com/article/ankle-joint-talocrural-subtalor-tibiofibular-joints" target="_blank" rel="noopener">Ankle</a>: Inadequate <a href="https://brookbushinstitute.com/glossary/posterior/" target="_blank" rel="noopener">posterior</a> <a href="https://brookbushinstitute.com/glossary/glide/" target="_blank" rel="noopener">glide</a> of the talus on the tibia</h4>
<ul>
 <li>Most of the research investigating the motion of the talus relates to an acute <a href="https://brookbushinstitute.com/article/ankle-joint-talocrural-subtalor-tibiofibular-joints" target="_blank" rel="noopener">ankle</a> sprain and/or chronic <a href="https://brookbushinstitute.com/article/ankle-joint-talocrural-subtalor-tibiofibular-joints" target="_blank" rel="noopener">ankle</a> <a id="stability" data-tip="1193" target="_blank" href="/glossary-term/stability" class="glossary">instability</a> (CAI). It is our <a id="hypothesis" data-tip="1446" target="_blank" href="/glossary-term/hypothesis" class="glossary">hypothesis</a> that these conditions are related to LED, as LED either predisposes an individual to such injuries or may be the result of these injuries. Further, an inability to <a id="glide" data-tip="1598" target="_blank" href="/glossary-term/glide" class="glossary">glide</a> the talus posteriorly is most often correlated with a <a href="https://brookbushinstitute.com/video/dorsiflexion-goniometry" target="_blank" rel="noopener">loss of dorsiflexion</a> (198 - 204), and a <a href="https://brookbushinstitute.com/video/dorsiflexion-goniometry" target="_blank" rel="noopener">loss of dorsiflexion</a> was used to define LED in the &quot;Evidence-based <a id="osteokinematic-motion" data-tip="1881" target="_blank" href="/glossary-term/osteokinematic-motion" class="glossary">Osteokinematic</a> Analysis.&quot; In a study by Denegar et al., laxity was significantly greater at the talocrural and subtalar joints in participants with a recent history (6 months) of an <a href="https://brookbushinstitute.com/article/ankle-joint-talocrural-subtalor-tibiofibular-joints" target="_blank" rel="noopener">ankle</a> sprain; however, <a id="anterior" data-tip="1566" target="_blank" href="/glossary-term/anterior" class="glossary">anterior</a> to <a id="posterior" data-tip="1565" target="_blank" href="/glossary-term/posterior" class="glossary">posterior</a> <a id="glide" data-tip="1598" target="_blank" href="/glossary-term/glide" class="glossary">glide</a> of the talus on the tibia (AP <a id="glide" data-tip="1598" target="_blank" href="/glossary-term/glide" class="glossary">glide</a>) remained restricted, even when dorsiflexion returned to normal (195). A very similar relationship was found in those with CAI; side to side motion was not markedly different, <a id="posterior" data-tip="1565" target="_blank" href="/glossary-term/posterior" class="glossary">posterior</a> to <a id="anterior" data-tip="1566" target="_blank" href="/glossary-term/anterior" class="glossary">anterior</a> motion of the talus on the tibia was hypermobile; however, stiffness was noted when an attempt was made to AP <a id="glide" data-tip="1598" target="_blank" href="/glossary-term/glide" class="glossary">glide</a> (196). Adding a potential reason for these findings, in a study by Wikstrom et al., a correlation was made between CAI and an anteriorly shifted talus (<a id="anterior" data-tip="1566" target="_blank" href="/glossary-term/anterior" class="glossary">anterior</a> positional fault) (197). Based on the findings by Wikstrom et al. and the <a href="https://brookbushinstitute.com/video/dorsiflexion-goniometry" target="_blank" rel="noopener">loss of dorsiflexion</a> associated with LED, it seems plausible that AP stiffness may be the result of adaptive shortening of <a id="posterior" data-tip="1565" target="_blank" href="/glossary-term/posterior" class="glossary">posterior</a> structures of the ankle (&quot;squeezing the talus&quot; anteriorly). This would be congruent with the &quot;Evidence-based Muscular Analysis&quot;, as the <a href="https://brookbushinstitute.com/article/gastrocnemius-plantaris" target="_blank" rel="noopener">gastrocnemius, plantaris</a>, <a href="https://brookbushinstitute.com/article/soleus" target="_blank" rel="noopener">soleus</a>, and <a href="https://brookbushinstitute.com/article/fibularis-muscles" target="_blank" rel="noopener">fibularis muscles</a> are <a id="prone" data-tip="1561" target="_blank" href="/glossary-term/prone" class="glossary">prone</a> to over-activity and adaptive shortening, and evidence of a loss of <a id="extensibility-2" data-tip="1308" target="_blank" href="/glossary-term/extensibility-2" class="glossary">extensibility</a> in <a id="posterior" data-tip="1565" target="_blank" href="/glossary-term/posterior" class="glossary">posterior</a> fascial structures (<a id="posterior" data-tip="1565" target="_blank" href="/glossary-term/posterior" class="glossary">posterior</a> capsule, Achilles tendon, crural fascia, etc.) seems plausible based on the findings in the <a id="evidence-based-practice" data-tip="1538" target="_blank" href="/glossary-term/evidence-based-practice" class="glossary">Evidence-based</a> Fascial Analysis. In practice, AP <a id="glide" data-tip="1598" target="_blank" href="/glossary-term/glide" class="glossary">glide</a> mobilizations have been correlated with improvements in dorsiflexion (198, 200, 202 - 204, 207), a reduction in pain (even in acute cases) (198, 199, 204), improvements in <a id="posture" data-tip="1659" target="_blank" href="/glossary-term/posture" class="glossary">postural</a> control (200, 202), fewer PT visits post-injury (198), and improvements in landing mechanics (201). Oddly, <a id="distraction" data-tip="1813" target="_blank" href="/glossary-term/distraction" class="glossary">traction</a> mobilization of the ankle does not appear to be beneficial for this same group (205, 206).</li>
</ul>
<h4><a href="https://brookbushinstitute.com/article/ankle-joint-talocrural-subtalor-tibiofibular-joints" target="_blank" rel="noopener">Ankle</a>: Inadequate <a href="https://brookbushinstitute.com/glossary/posterior/" target="_blank" rel="noopener">posterior</a> <a href="https://brookbushinstitute.com/glossary/glide/" target="_blank" rel="noopener">glide</a> of the <a href="https://brookbushinstitute.com/glossary/lateral/" target="_blank" rel="noopener">lateral</a> malleolus on the tibia (distal tibiofibular joint) or hypermobility</h4>
<ul>
 <li>The <a id="distal" data-tip="1563" target="_blank" href="/glossary-term/distal" class="glossary">distal</a> <a href="https://brookbushinstitute.com/article/ankle-joint-talocrural-subtalor-tibiofibular-joints" target="_blank" rel="noopener">tibiofibular joint</a> appears to have two common dysfunctional patterns (212). One scenario results in an <a id="anterior" data-tip="1566" target="_blank" href="/glossary-term/anterior" class="glossary">anterior</a> position fault (inadequate <a id="posterior" data-tip="1565" target="_blank" href="/glossary-term/posterior" class="glossary">posterior</a> <a id="glide" data-tip="1598" target="_blank" href="/glossary-term/glide" class="glossary">glide</a>) of the fibula on the tibia and <a id="hypomobility" data-tip="1673" target="_blank" href="/glossary-term/hypomobility" class="glossary">hypomobility</a> (197, 209); the other results in <a id="hypermobility" data-tip="1677" target="_blank" href="/glossary-term/hypermobility" class="glossary">hypermobility</a> and a <a id="posterior" data-tip="1565" target="_blank" href="/glossary-term/posterior" class="glossary">posterior</a> position fault when the foot is dorsiflexed (208, 210-212). This <a id="assessment" data-tip="1478" target="_blank" href="/glossary-term/assessment" class="glossary">assessment</a> of the research seems to be supported by the Whitman et al. clinical prediction rule, as <a id="distal" data-tip="1563" target="_blank" href="/glossary-term/distal" class="glossary">distal</a> <a href="https://brookbushinstitute.com/article/ankle-joint-talocrural-subtalor-tibiofibular-joints" target="_blank" rel="noopener">tibiofibular joint</a> stiffness was one of 5 signs indicating a higher likelihood of positive outcomes using joint manipulation post ankle sprain (214). Clinically, the <a id="release" data-tip="1249" target="_blank" href="/glossary-term/release" class="glossary">release</a> of the <a href="https://brookbushinstitute.com/article/fibularis-muscles" target="_blank" rel="noopener">fibularis muscles</a> has also proven helpful in increasing <a id="distal" data-tip="1563" target="_blank" href="/glossary-term/distal" class="glossary">distal</a> <a href="https://brookbushinstitute.com/article/ankle-joint-talocrural-subtalor-tibiofibular-joints" target="_blank" rel="noopener">tibiofibular joint</a> <a id="hypomobility" data-tip="1673" target="_blank" href="/glossary-term/hypomobility" class="glossary">hypomobility</a>. The addition of this intervention was based on the potential of the <a href="https://brookbushinstitute.com/article/fibularis-muscles" target="_blank" rel="noopener">fibularis muscles</a> creating a <a id="posterior" data-tip="1565" target="_blank" href="/glossary-term/posterior" class="glossary">posterior</a> to <a id="anterior" data-tip="1566" target="_blank" href="/glossary-term/anterior" class="glossary">anterior</a> pull as the tendon passes through a groove on the <a id="posterior" data-tip="1565" target="_blank" href="/glossary-term/posterior" class="glossary">posterior</a> <a id="lateral" data-tip="1567" target="_blank" href="/glossary-term/lateral" class="glossary">lateral</a> malleolus. An interesting study by Grindstaff et al., demonstrated <a id="anterior" data-tip="1566" target="_blank" href="/glossary-term/anterior" class="glossary">anterior</a> to <a id="posterior" data-tip="1565" target="_blank" href="/glossary-term/posterior" class="glossary">posterior</a> mobilization of the <a id="distal" data-tip="1563" target="_blank" href="/glossary-term/distal" class="glossary">distal</a> <a href="https://brookbushinstitute.com/article/ankle-joint-talocrural-subtalor-tibiofibular-joints" target="_blank" rel="noopener">tibiofibular joint</a> increased <a href="https://brookbushinstitute.com/article/soleus" target="_blank" rel="noopener">soleus</a> activity in individuals with CAI (213).</li>
</ul>
<h4><a href="https://brookbushinstitute.com/article/ankle-joint-talocrural-subtalor-tibiofibular-joints" target="_blank" rel="noopener">Ankle</a>/<a href="https://brookbushinstitute.com/article/knee" target="_blank" rel="noopener">Knee</a>: Inadequate <a href="https://brookbushinstitute.com/glossary/anterior/" target="_blank" rel="noopener">anterior</a> <a href="https://brookbushinstitute.com/glossary/glide/" target="_blank" rel="noopener">glide</a> of the fibular head on the tibia or hypermobility</h4>
<ul>
 <li>It is hypothesized that <a id="proximal" data-tip="1564" target="_blank" href="/glossary-term/proximal" class="glossary">proximal</a> and <a id="distal" data-tip="1563" target="_blank" href="/glossary-term/distal" class="glossary">distal</a> <a href="https://brookbushinstitute.com/article/ankle-joint-talocrural-subtalor-tibiofibular-joints" target="_blank" rel="noopener">tibiofibular joint</a> motion are linked; moving in opposite directions due to the fiber arrangement of the interosseous membrane. Relative to dysfunction this would imply that excessive <a id="anterior" data-tip="1566" target="_blank" href="/glossary-term/anterior" class="glossary">anterior</a> <a id="glide" data-tip="1598" target="_blank" href="/glossary-term/glide" class="glossary">glide</a> of the <a id="lateral" data-tip="1567" target="_blank" href="/glossary-term/lateral" class="glossary">lateral</a> malleolus results in excessive <a id="posterior" data-tip="1565" target="_blank" href="/glossary-term/posterior" class="glossary">posterior</a> <a id="glide" data-tip="1598" target="_blank" href="/glossary-term/glide" class="glossary">glide</a> of the fibular head. Further, since their motions are linked, either <a href="https://brookbushinstitute.com/article/ankle-joint-talocrural-subtalor-tibiofibular-joints" target="_blank" rel="noopener">ankle</a> or <a href="https://brookbushinstitute.com/article/knee" target="_blank" rel="noopener">knee</a> dysfunction may result in dysfunction in both <a id="proximal" data-tip="1564" target="_blank" href="/glossary-term/proximal" class="glossary">proximal</a> and <a id="distal" data-tip="1563" target="_blank" href="/glossary-term/distal" class="glossary">distal</a> joints. Relative to the changes in <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> activity in those exhibiting LED, this <a id="hypothesis" data-tip="1446" target="_blank" href="/glossary-term/hypothesis" class="glossary">hypothesis</a> adds further congruence as the commonly over-active tibial external rotators (<a href="https://brookbushinstitute.com/article/tensor-fascia-latae-tfl" target="_blank" rel="noopener">TFL</a>, <a href="https://brookbushinstitute.com/article/quadriceps-vastus-muscles" target="_blank" rel="noopener">vastus lateralis</a>, <a href="https://brookbushinstitute.com/article/quadriceps-vastus-muscles" target="_blank" rel="noopener">biceps femoris</a> via the ITB) would also create a <a id="posterior" data-tip="1565" target="_blank" href="/glossary-term/posterior" class="glossary">posterior</a> pull on the fibular head. Although this <a id="hypothesis" data-tip="1446" target="_blank" href="/glossary-term/hypothesis" class="glossary">hypothesis</a> has proven clinically <a id="relevance" data-tip="1505" target="_blank" href="/glossary-term/relevance" class="glossary">relevant</a> when considering exercise and soft tissue techniques (215), the research suggests that joint mobilizations may be most effective when done for the joint most <a id="proximal" data-tip="1564" target="_blank" href="/glossary-term/proximal" class="glossary">proximal</a> to the symptoms reported. <a id="posterior" data-tip="1565" target="_blank" href="/glossary-term/posterior" class="glossary">posterior</a> to <a id="anterior" data-tip="1566" target="_blank" href="/glossary-term/anterior" class="glossary">anterior</a> mobilization of the <a id="proximal" data-tip="1564" target="_blank" href="/glossary-term/proximal" class="glossary">proximal</a> <a href="https://brookbushinstitute.com/article/ankle-joint-talocrural-subtalor-tibiofibular-joints" target="_blank" rel="noopener">tibiofibular joint</a> is correlated with a reduction in <a href="https://brookbushinstitute.com/article/knee" target="_blank" rel="noopener">knee</a> pain (215 - 217); however, it does not appear that <a id="proximal" data-tip="1564" target="_blank" href="/glossary-term/proximal" class="glossary">proximal</a> <a href="https://brookbushinstitute.com/article/ankle-joint-talocrural-subtalor-tibiofibular-joints" target="_blank" rel="noopener">tibiofibular joint</a> mobilization improves <a href="https://brookbushinstitute.com/article/ankle-joint-talocrural-subtalor-tibiofibular-joints" target="_blank" rel="noopener">ankle</a> dysfunction (217). Further, in the study by Grindstaff et al. mentioned previously, it was found that <a id="posterior" data-tip="1565" target="_blank" href="/glossary-term/posterior" class="glossary">posterior</a> to <a id="anterior" data-tip="1566" target="_blank" href="/glossary-term/anterior" class="glossary">anterior</a> mobilizations of the <a id="proximal" data-tip="1564" target="_blank" href="/glossary-term/proximal" class="glossary">proximal</a> <a href="https://brookbushinstitute.com/article/ankle-joint-talocrural-subtalor-tibiofibular-joints" target="_blank" rel="noopener">tibiofibular joint</a> did not affect <a href="https://brookbushinstitute.com/article/soleus" target="_blank" rel="noopener">soleus</a> or <a href="https://brookbushinstitute.com/article/fibularis-muscles" target="_blank" rel="noopener">fibularis muscle</a> activity (213). Similar to the <a id="distal" data-tip="1563" target="_blank" href="/glossary-term/distal" class="glossary">distal</a> <a href="https://brookbushinstitute.com/article/ankle-joint-talocrural-subtalor-tibiofibular-joints" target="_blank" rel="noopener">tibiofibular joint</a>, the <a id="proximal" data-tip="1564" target="_blank" href="/glossary-term/proximal" class="glossary">proximal</a> <a href="https://brookbushinstitute.com/article/ankle-joint-talocrural-subtalor-tibiofibular-joints" target="_blank" rel="noopener">tibiofibular joint</a> may alternatively become <a id="hypermobility" data-tip="1679" target="_blank" href="/glossary-term/hypermobility" class="glossary">hypermobile</a>, predisposing an individual to subluxation of the fibular head (215, 219 - 222). Obviously, in cases of <a id="hypermobility" data-tip="1677" target="_blank" href="/glossary-term/hypermobility" class="glossary">hypermobility</a> mobilizations are not recommended.</li>
</ul>
<img src="https://www.datocms-assets.com/25800/1649100576-ankle-frontal-cross-section.png" title="ankle-frontal-cross-section" alt="ankle-frontal-cross-section">

Ankle

<h4><a href="https://brookbushinstitute.com/article/knee" target="_blank" rel="noopener">Knee</a>: Inadequate anterior glide of the tibia on the femur (the lateral compartment may be more restricted)</h4>
<ul>
 <li>It is hypothesized that <a id="arthrokinematics" data-tip="1863" target="_blank" href="/glossary-term/arthrokinematics" class="glossary">arthrokinematic</a> dysfunction of the tibiofemoral joint results from inadequate <a id="anterior" data-tip="1566" target="_blank" href="/glossary-term/anterior" class="glossary">anterior</a> <a id="glide" data-tip="1598" target="_blank" href="/glossary-term/glide" class="glossary">glide</a> of the tibia on the femur during terminal extension. This <a id="hypothesis" data-tip="1446" target="_blank" href="/glossary-term/hypothesis" class="glossary">hypothesis</a> is congruent with the over-activity of the <a href="https://brookbushinstitute.com/article/quadriceps-vastus-muscles" target="_blank" rel="noopener">biceps femoris</a> noted in the &quot;Evidence-based Muscular Analysis&quot;. Further, it may be hypothesized that the <a id="lateral" data-tip="1567" target="_blank" href="/glossary-term/lateral" class="glossary">lateral</a> compartment may be more restricted as evidenced by the over-activity of all external rotators of the tibia (<a href="https://brookbushinstitute.com/article/tensor-fascia-latae-tfl" target="_blank" rel="noopener">TFL</a>, <a href="https://brookbushinstitute.com/article/quadriceps-vastus-muscles" target="_blank" rel="noopener">vastus lateralis</a>, <a href="https://brookbushinstitute.com/article/quadriceps-vastus-muscles" target="_blank" rel="noopener">biceps femoris</a> via the ITB) and the common occurrence of <a href="https://brookbushinstitute.com/video/feet-turn-out-breakdown" target="_blank" rel="noopener">feet turn out</a> (<a id="lateral" data-tip="1567" target="_blank" href="/glossary-term/lateral" class="glossary">lateral</a> <a id="spin" data-tip="1603" target="_blank" href="/glossary-term/spin" class="glossary">spin</a> of the tibia) noted in the &quot;evidence-based <a id="osteokinematic-motion" data-tip="1881" target="_blank" href="/glossary-term/osteokinematic-motion" class="glossary">osteokinematic</a> <a id="model" data-tip="1469" target="_blank" href="/glossary-term/model" class="glossary">model</a>.&quot; Unfortunately, direct evidence of these altered <a id="arthrokinematics" data-tip="1859" target="_blank" href="/glossary-term/arthrokinematics" class="glossary">arthrokinematics</a> is not available. One study showed that rotation played a larger <a id="roll" data-tip="1602" target="_blank" href="/glossary-term/roll" class="glossary">roll</a> than <a id="glide" data-tip="1598" target="_blank" href="/glossary-term/glide" class="glossary">glide</a> in terminal knee extension during weight-bearing activities (223), which may partially explain the clinical observation of passive accessory stiffness of the knee being less common than stiffness in other joints of the lower extremity (<a href="https://brookbushinstitute.com/article/ankle-joint-talocrural-subtalor-tibiofibular-joints" target="_blank" rel="noopener">ankle</a>, <a href="https://brookbushinstitute.com/article/ankle-joint-talocrural-subtalor-tibiofibular-joints" target="_blank" rel="noopener">tibiofibular joints</a>, <a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">hip</a>). An exception to this observation would be the stiffness noted post knee surgery. Indirect evidence does exist, as the majority of studies on knee joint mobilization use either <a id="posterior" data-tip="1565" target="_blank" href="/glossary-term/posterior" class="glossary">posterior</a> to <a id="anterior" data-tip="1566" target="_blank" href="/glossary-term/anterior" class="glossary">anterior</a> tibia on femur mobilizations, or <a id="anterior" data-tip="1566" target="_blank" href="/glossary-term/anterior" class="glossary">anterior</a> to <a id="posterior" data-tip="1565" target="_blank" href="/glossary-term/posterior" class="glossary">posterior</a> femur on tibia mobilizations, and knee mobilizations have been shown to be effective for those with knee pain or diagnosed osteoarthritis. Knee mobilizations have proven very effective for reducing pain (224, 226-227, 232-233), increasing range of motion (ROM) in those exhibiting limitation (228,230,232), improving function (although not in all cases, additional strengthening may be necessary) (224, 228, 231), quality of motion (225), and may result in an immediate increase in <a href="https://brookbushinstitute.com/article/quadriceps-vastus-muscles" target="_blank" rel="noopener">quadriceps</a> strength and activity (229).</li>
</ul>
<h4><a href="https://brookbushinstitute.com/article/knee" target="_blank" rel="noopener">Knee</a>: Excessive lateral glide of the patella on the femur is the result of forces related to <a href="https://brookbushinstitute.com/video/overhead-squat-assessment-6-knees-bow-in-breakdown" target="_blank" rel="noopener">Knees Bow In</a></h4>
<ul>
 <li>Although excessive <a id="lateral" data-tip="1567" target="_blank" href="/glossary-term/lateral" class="glossary">lateral</a> <a id="glide" data-tip="1598" target="_blank" href="/glossary-term/glide" class="glossary">glide</a> of the patella is an often-cited dysfunction, it is widely accepted that this is caused by forces related to a <a href="https://brookbushinstitute.com/video/overhead-squat-assessment-6-knees-bow-in-breakdown" target="_blank" rel="noopener">functional valgus (knees Bow In)</a>. These forces may include altered <a href="https://brookbushinstitute.com/article/quadriceps-vastus-muscles" target="_blank" rel="noopener">quadriceps</a> angle (Q-angle), tibial external rotation, femoral internal rotation, increased <a id="tension" data-tip="1229" target="_blank" href="/glossary-term/tension" class="glossary">tension</a> on the <a id="lateral" data-tip="1567" target="_blank" href="/glossary-term/lateral" class="glossary">lateral</a> retinaculum via the iliotibial band (ITB), and potentially a decrease in <a href="https://brookbushinstitute.com/article/quadriceps-vastus-muscles" target="_blank" rel="noopener">VMO</a> activity. A wonderful review of this relationship can be found in a paper published in 2003 by Christopher M. Powers, Ph.D. (234). Not surprisingly, no recent studies could be located that investigated the use of patellofemoral mobilizations alone, although some evidence exists that patellofemoral mobilizations may be effective when used in conjunction with other therapeutic modalities (235, 236). It is the stance of the Brookbush Institute that correcting LED would be a better treatment option for patellofemoral pain and that mobilization of the patellofemoral joint is rarely necessary or effective, and should never be considered therapy when used alone.</li>
</ul>
<img src="https://www.datocms-assets.com/25800/1649100510-lateral-knee.png" title="Knee joint with ligaments" alt="Knee joint with ligaments">

Knee

<h4><a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">Hip</a>: Inadequate posterior and glide of the femur in the acetabulum</h4>
<ul>
 <li>There is a surprisingly scarce amount of research on hip <a id="arthrokinematics" data-tip="1859" target="_blank" href="/glossary-term/arthrokinematics" class="glossary">arthrokinematics</a> and the effects of hip mobilization. Research has called for a better understanding of <a id="arthrokinematics" data-tip="1859" target="_blank" href="/glossary-term/arthrokinematics" class="glossary">arthrokinematics</a> and femur-labrum contact, asserting that bone-on-bone <a id="model" data-tip="1471" target="_blank" href="/glossary-term/model" class="glossary">models</a> are insufficient (238). Another study on osteoarthritic patients demonstrated that pain during the FABER and FADIR tests could be explained by fibrotic shortening of the <a id="inferior" data-tip="1569" target="_blank" href="/glossary-term/inferior" class="glossary">inferior</a> capsule, resulting in an increase in capsule stretching, stretching of the investing sensory nerves, <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> spasm, and a reduction in <a id="arthrokinematics" data-tip="1701" target="_blank" href="/glossary-term/arthrokinematics" class="glossary">arthrokinematic motion</a> increasing <a id="compression" data-tip="1596" target="_blank" href="/glossary-term/compression" class="glossary">compressive forces</a> (239). Although this is a great study, it can only lead to more <a id="hypothesis" data-tip="1447" target="_blank" href="/glossary-term/hypothesis" class="glossary">hypotheses</a> to be tested. Research has demonstrated that the femur may <a id="glide" data-tip="1598" target="_blank" href="/glossary-term/glide" class="glossary">glide</a> <a id="anterior" data-tip="1566" target="_blank" href="/glossary-term/anterior" class="glossary">anterior</a> and <a id="posterior" data-tip="1565" target="_blank" href="/glossary-term/posterior" class="glossary">posterior</a> in the acetabulum (237, 240). <a id="inferior" data-tip="1569" target="_blank" href="/glossary-term/inferior" class="glossary">inferior</a>, <a id="anterior" data-tip="1566" target="_blank" href="/glossary-term/anterior" class="glossary">anterior</a>, and <a id="posterior" data-tip="1565" target="_blank" href="/glossary-term/posterior" class="glossary">posterior</a> mobilizations of the hip have shown promising results for improving range of motion, <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> strength, and reducing pain (240-242). <a id="superior" data-tip="1570" target="_blank" href="/glossary-term/superior" class="glossary">Superior</a> to <a id="inferior" data-tip="1569" target="_blank" href="/glossary-term/inferior" class="glossary">inferior</a> Grade IV mobilizations increased range of motion and <a href="https://brookbushinstitute.com/article/gluteus-medius" target="_blank" rel="noopener">gluteus medius</a> strength, and Grade IV <a id="posterior" data-tip="1565" target="_blank" href="/glossary-term/posterior" class="glossary">posterior</a> to <a id="anterior" data-tip="1566" target="_blank" href="/glossary-term/anterior" class="glossary">anterior</a> mobilizations increased <a href="https://brookbushinstitute.com/article/gluteus-maximus" target="_blank" rel="noopener">gluteus maximus</a> strength (241-242). In the study by Loubert et al, it was shown that end range <a id="anterior" data-tip="1566" target="_blank" href="/glossary-term/anterior" class="glossary">anterior</a> to <a id="posterior" data-tip="1565" target="_blank" href="/glossary-term/posterior" class="glossary">posterior</a> mobilizations were necessary to improve hip flexion ROM and that mobilizations performed in a more neutral hip position resulted in little if any change (240). Examining the methods used in the 3 studies on mobilizations cited in this section, all mobilizations were performed in the end range (240-242). Based on the current research the Brookbush Institute (BI) recommends end range, Grade III and IV hip mobilizations, done prior to <a id="activation-technique" data-tip="1531" target="_blank" href="/glossary-term/activation-technique" class="glossary">activation techniques</a>. Further, BI hypothesizes that the femur has a propensity to excessively <a id="glide" data-tip="1598" target="_blank" href="/glossary-term/glide" class="glossary">glide</a> <a id="anterior" data-tip="1566" target="_blank" href="/glossary-term/anterior" class="glossary">anterior</a> and <a id="superior" data-tip="1570" target="_blank" href="/glossary-term/superior" class="glossary">Superior</a> in the capsule. This is based on the increase in activity noted in <a id="posterior" data-tip="1565" target="_blank" href="/glossary-term/posterior" class="glossary">posterior</a> hip muscles (<a href="https://brookbushinstitute.com/article/piriformis" target="_blank" rel="noopener">piriformis</a>, <a href="https://brookbushinstitute.com/article/deep-rotators-of-the-hip" target="_blank" rel="noopener">deep rotators</a>) and femoral internal rotators (<a href="https://brookbushinstitute.com/article/tensor-fascia-latae-tfl" target="_blank" rel="noopener">tensor fasciae latae (TFL)</a>, <a href="https://brookbushinstitute.com/article/gluteus-minimus" target="_blank" rel="noopener">gluteus minimus</a>) and a hypothesized fibrotic shortening of the <a id="inferior" data-tip="1569" target="_blank" href="/glossary-term/inferior" class="glossary">inferior</a> and <a id="posterior" data-tip="1565" target="_blank" href="/glossary-term/posterior" class="glossary">posterior</a> capsules. The direction of mobilization most often performed by the Brookbush Institute is <a id="lateral" data-tip="1567" target="_blank" href="/glossary-term/lateral" class="glossary">lateral</a> <a id="distraction" data-tip="1591" target="_blank" href="/glossary-term/distraction" class="glossary">distractions</a> at end-range hip flexion and internal rotation.</li>
</ul>
<img src="https://www.datocms-assets.com/25800/1649100003-1632853012-hip-cadaver.jpg" title="Cadaver Dissection of Hip Joint with Soft Tissue Removed and Bony Landmarks Labeled" alt="Cadaver Dissection of Hip Joint with Soft Tissue Removed and Bony Landmarks Labeled">

<ul>
 <li>Joint mobilizations may have a positive effect on <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> strength.</li>
 <li><a href="https://brookbushinstitute.com/article/ankle-joint-talocrural-subtalor-tibiofibular-joints" target="_blank" rel="noopener">Ankle</a>: <a id="hypermobility" data-tip="1677" target="_blank" href="/glossary-term/hypermobility" class="glossary">Hypermobility</a> of the tibiotalar and talocalcaneal joints in <a id="lateral" data-tip="1567" target="_blank" href="/glossary-term/lateral" class="glossary">lateral</a> <a id="glide" data-tip="1598" target="_blank" href="/glossary-term/glide" class="glossary">glide</a> and <a id="posterior" data-tip="1565" target="_blank" href="/glossary-term/posterior" class="glossary">posterior</a> to <a id="anterior" data-tip="1566" target="_blank" href="/glossary-term/anterior" class="glossary">anterior</a> <a id="glide" data-tip="1598" target="_blank" href="/glossary-term/glide" class="glossary">glide</a> is common; however, <a id="hypomobility" data-tip="1673" target="_blank" href="/glossary-term/hypomobility" class="glossary">hypomobility</a> is common for <a id="anterior" data-tip="1566" target="_blank" href="/glossary-term/anterior" class="glossary">anterior</a> to <a id="posterior" data-tip="1565" target="_blank" href="/glossary-term/posterior" class="glossary">posterior</a> <a href="https://brookbushinstitute.com/glossary/glide/" target="_blank" rel="noopener">glide</a> of the talus on the tibia. Further, an insufficient <a id="posterior" data-tip="1565" target="_blank" href="/glossary-term/posterior" class="glossary">posterior</a> <a id="glide" data-tip="1598" target="_blank" href="/glossary-term/glide" class="glossary">glide</a> of the talus on the tibia is correlated with a <a href="https://brookbushinstitute.com/video/dorsiflexion-goniometry" target="_blank" rel="noopener">loss of dorsiflexion</a>.</li>
 <li><a href="https://brookbushinstitute.com/article/ankle-joint-talocrural-subtalor-tibiofibular-joints" target="_blank" rel="noopener">Ankle</a>: Two patterns of dysfunction are common for the <a id="distal" data-tip="1563" target="_blank" href="/glossary-term/distal" class="glossary">distal</a> tibiofibular joint. <a id="hypomobility" data-tip="1673" target="_blank" href="/glossary-term/hypomobility" class="glossary">Hypomobility</a> and inadequate <a id="posterior" data-tip="1565" target="_blank" href="/glossary-term/posterior" class="glossary">posterior</a> <a href="https://brookbushinstitute.com/glossary/glide/" target="_blank" rel="noopener">glide</a> of the <a href="https://brookbushinstitute.com/glossary/lateral/" target="_blank" rel="noopener">lateral</a> malleolus on the tibia, and <a id="hypermobility" data-tip="1677" target="_blank" href="/glossary-term/hypermobility" class="glossary">hypermobility</a> and excessive <a id="posterior" data-tip="1565" target="_blank" href="/glossary-term/posterior" class="glossary">posterior</a> <a id="glide" data-tip="1598" target="_blank" href="/glossary-term/glide" class="glossary">glide</a> during end range dorsiflexion. Mobilization is only recommended for the <a id="hypomobility" data-tip="1676" target="_blank" href="/glossary-term/hypomobility" class="glossary">hypomobile</a> pattern.</li>
 <li><a href="https://brookbushinstitute.com/article/ankle-joint-talocrural-subtalor-tibiofibular-joints" target="_blank" rel="noopener">Ankle</a>/<a href="https://brookbushinstitute.com/article/knee" target="_blank" rel="noopener">Knee</a>: Two patterns of dysfunction are common for the <a id="proximal" data-tip="1564" target="_blank" href="/glossary-term/proximal" class="glossary">proximal</a> tibiofibular joint. <a id="hypomobility" data-tip="1673" target="_blank" href="/glossary-term/hypomobility" class="glossary">Hypomobility</a> and inadequate <a id="anterior" data-tip="1566" target="_blank" href="/glossary-term/anterior" class="glossary">anterior</a> <a href="https://brookbushinstitute.com/glossary/glide/" target="_blank" rel="noopener">glide</a> of the fibula on the tibia, and <a id="hypermobility" data-tip="1677" target="_blank" href="/glossary-term/hypermobility" class="glossary">hypermobility</a> may predispose an individual to subluxation. Mobilization is only recommended for the <a id="hypomobility" data-tip="1676" target="_blank" href="/glossary-term/hypomobility" class="glossary">hypomobile</a> pattern. Further, relative to mobilizations, there does not seem to be a relationship between <a id="proximal" data-tip="1564" target="_blank" href="/glossary-term/proximal" class="glossary">proximal</a> and <a id="distal" data-tip="1563" target="_blank" href="/glossary-term/distal" class="glossary">distal</a> tibiofibular joints.</li>
 <li><a href="https://brookbushinstitute.com/article/knee" target="_blank" rel="noopener">Knee</a>: Dysfunction of the knee is presumed to result in an inadequate <a id="anterior" data-tip="1566" target="_blank" href="/glossary-term/anterior" class="glossary">anterior</a> <a id="glide" data-tip="1598" target="_blank" href="/glossary-term/glide" class="glossary">glide</a> of the tibia on the femur (the <a id="lateral" data-tip="1567" target="_blank" href="/glossary-term/lateral" class="glossary">lateral</a> compartment may be more restricted). This presumption is based on the effectiveness of <a id="anterior" data-tip="1566" target="_blank" href="/glossary-term/anterior" class="glossary">anterior</a> to <a id="posterior" data-tip="1565" target="_blank" href="/glossary-term/posterior" class="glossary">posterior</a> mobilizations of the femur on the tibia in full extension. Note, research does not <a id="base-of-support" data-tip="1197" target="_blank" href="/glossary-term/base-of-support" class="glossary">support</a> the use of patellofemoral mobilizations as a sole treatment option for knee pain.</li>
 <li><a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">Hip</a>: It is hypothesized that dysfunction results in an inadequate posterior/inferior <a id="glide" data-tip="1598" target="_blank" href="/glossary-term/glide" class="glossary">glide</a> of the femur in the acetabulum. However, research suggests that end-range mobilizations in any direction may be beneficial and result in positive changes in <a href="https://brookbushinstitute.com/article/gluteus-maximus" target="_blank" rel="noopener">gluteus maximus</a> and <a href="https://brookbushinstitute.com/article/gluteus-medius" target="_blank" rel="noopener">gluteus medius</a> strength. The Brookbush Institute recommends <a id="lateral" data-tip="1567" target="_blank" href="/glossary-term/lateral" class="glossary">lateral</a> mobilizations in (pain-free) end range flexion and internal rotation.</li>
</ul>
<h4>Summary of Issues with the Evidence-based Arthrokinematic Analysis:</h4>
<ul>
 <li>Research is needed to confirm altered <a id="arthrokinematics" data-tip="1859" target="_blank" href="/glossary-term/arthrokinematics" class="glossary">arthrokinematics</a> in vivo.</li>
 <li>Research is also needed to identify the changes in <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> activity, capsule <a id="extensibility-2" data-tip="1308" target="_blank" href="/glossary-term/extensibility-2" class="glossary">extensibility</a>, and altered force vectors that may be contributing to altered <a id="arthrokinematics" data-tip="1859" target="_blank" href="/glossary-term/arthrokinematics" class="glossary">arthrokinematics</a>.</li>
 <li>Research is needed to identify the effect mobilizations are having on tissues (how do mobilizations work?)</li>
 <li>Hip mobilizations need to be compared on the basis of assessed dysfunction, increases in range of motion, increased <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> strength, and pain. It seems unlikely that mobilizations in all directions are equally effective.</li>
</ul>
<img src="https://www.datocms-assets.com/25800/1649099731-achilles_insertional_calcific_tendinosis_labeled.jpg" alt="X-ray of Achilles tendinopathy with calcification of Achilles tendon insertion">By Mikael H&#xE4;ggstr&#xF6;m - Own work, CC0, https://commons.wikimedia.org/w/index.php?curid=56033977

The Lower Extremity Dysfunction (LED) <a id="model" data-tip="1469" target="_blank" href="/glossary-term/model" class="glossary">model</a> is constructed based on research demonstrating the maladaptive alterations of tissues and motion associated with common impairments of the human movement system. If we create a list of these impairments, this adds to the definition of the LED <a id="model" data-tip="1469" target="_blank" href="/glossary-term/model" class="glossary">model</a>, as the <a id="model" data-tip="1469" target="_blank" href="/glossary-term/model" class="glossary">model</a> itself could be defined as the expected maladaptive changes to arise from those impairments.
<ul>
 <li>Ankle/Foot
 <ul>
 <li>Medial tibial stress syndrome (24, 34, 44)</li>
 <li>Pronation (30, 34, 44)</li>
 <li>Ankle Sprain (Inversion sprain) (62, 75, 123-124, 195, 198 -199, 203 - 204, 207, 211-212)</li>
 <li>Ankle <a id="stability" data-tip="1193" target="_blank" href="/glossary-term/stability" class="glossary">instability</a> (19, 34, 71 - 74, 126, 196-197, 200 -202, 205-206, 208-210, 213, 218)</li>
 <li>Achilles tendinopathy (31, 34, 42, 44, 156, 159-167)</li>
 <li>Tibialis <a id="posterior" data-tip="1565" target="_blank" href="/glossary-term/posterior" class="glossary">posterior</a> tendinopathy (36 - 39, 110, 115-117, 121</li>
 <li>Plantar fasciitis (plantar heel pain,) (43, 69, 111, 153-158)</li>
 </ul>
 </li>
 <li>Knee
 <ul>
 <li>Anterior cruciate ligament injury (16, 230, 234)</li>
 <li>Functional valgus (16 - 18, 23, 26-29, 234)</li>
 <li>Knee pain (patellofemoral pain syndrome, jumper&apos;s knee ) (46, 48 - 51, 53-54,56, 58-59, 93, 102, 170, 225, 234-236)</li>
 <li>Lateral knee pain (iliotibial band syndrome, runner&apos;s knee) (172, 215-216)</li>
 <li>Knee osteoarthritis (217, 224, 227, 228)</li>
 <li>Knee <a id="effusion" data-tip="1459" target="_blank" href="/glossary-term/effusion" class="glossary">effusion</a> (100)</li>
 <li>Proximal tibiofibular joint pathology (215-217)</li>
 <li>Tibiofibular joint subluxation/dislocation (218-222)</li>
 <li>Medial and <a id="lateral" data-tip="1567" target="_blank" href="/glossary-term/lateral" class="glossary">Lateral</a> heel whip (45)</li>
 </ul>
 </li>
 <li>Hip
 <ul>
 <li>Trigger points (84)</li>
 <li>Abductor tendon tear (87)</li>
 <li>Adductor Groin Strain (94 - 97)</li>
 <li>Femoral acetabular impingement (FAI) (238)</li>
 <li>Hip Osteoarthritis (83, 239)</li>
 </ul>
 </li>
 <li>Lumbosacral
 <ul>
 <li>Low Back Pain (76, 78, 128-129)</li>
 <li>Sacroiliac joint pain (77)</li>
 </ul>
 </li>
</ul>

Symptoms, Injuries and Diagnoses Associated with Lower Extremity Dysfunction LED

I hope you have enjoyed this article. I believe it is the first attempt at integrating a <a id="posture" data-tip="1659" target="_blank" href="/glossary-term/posture" class="glossary">postural</a> dysfunction/movement impairment <a id="model" data-tip="1469" target="_blank" href="/glossary-term/model" class="glossary">model</a> with <a id="osteokinematic-motion" data-tip="1881" target="_blank" href="/glossary-term/osteokinematic-motion" class="glossary">osteokinematic</a>, muscular, fascial, myofascial synergy, motor control, and <a id="arthrokinematics" data-tip="1863" target="_blank" href="/glossary-term/arthrokinematics" class="glossary">arthrokinematic</a> based approaches. Further, I have attempted to be as thorough in my review of <a id="relevance" data-tip="1505" target="_blank" href="/glossary-term/relevance" class="glossary">relevant</a> research as possible in pursuit of a comprehensive evidence-based <a id="model" data-tip="1469" target="_blank" href="/glossary-term/model" class="glossary">model</a>. If you take a moment to review the bibliography you will also notice that it is sub-divided into categories for easy review of any topic addressed in this article. It is my sincere hope that readers will have suggestions for additions to the bibliography, or alternate interpretations of the research cited as we continue to pursue <a id="optimal" data-tip="1571" target="_blank" href="/glossary-term/optimal" class="glossary">optimal</a> practice. Although this article represents a giant leap from my previous analysis, there is still a tremendous amount of work to be done.
<h4>Accreditation Note:</h4>
We expect all professionals to respect the boundaries of their scope of practice and act accordingly. This course does not increase the scope of any professional. Further, we have been asked to add the following note:
<ul>
 <li>Australian Registered Exercise Professionals (AusREPs) must remain within their <a href="https://bp-fitnessaustralia-production.s3.amazonaws.com/uploads/uploaded_file/file/392024/Scope_of_Practice_June_2019.pdf" target="_blank" rel="noopener">Scope of Practice</a>.</li>
</ul>

Bibliography

<html><head></head><body>© Brent Brookbush 2017
Questions, comments and criticisms welcomed and encouraged.</body></html>

Copyright

A-Band - Refers to the part of the muscle cell that looks darker under a microscope.  This area of the cell is darker due to parallel arrangement of thicker filaments (myosin) and overlap with the thinner filaments (actin).
<ul>
 	<li>As a muscle contracts, the A-band is where actin and myosin interact.</li>
</ul>
<ol>
 	<li>Saladin, K. (2014). Anatomy &amp; physiology: The unity of form and function. McGraw-Hill Higher Education, New York. ISBN: 9780073403717</li>
</ol>

Accuracy - the proportion of individuals correctly identified by the test results.
<ul>
 	<li>For example, a special test with perfect accuracy would imply a test has 100% specificity, 100% sensitivity, 100% positive predictive value and 100% negative predictive values.</li>
</ul>

Action Potential - A rapid change in voltage, resulting in a wave of excitation, that may result in stimulation of a nerve or muscle cell.
<ul>
 	<li>In order for an action potential to be initiated, the resting membrane voltage must exceed the excitation threshold, which then results in a cascade of depolarization and the "wave of excitation." Any stimulus below that threshold will not result in an action potential, and a stimulus greater than the threshold will not increase a single action potential, but may result in additional action potentials.  In this way, the action potential functions more like an on/off switch (all or none), and less like a dimmer switch.</li>
</ul>

A single-joint movement pattern (most often) designed to load a specific under-active muscle(s), while minimizing the contribution of over-active synergists via specific cues/joint motions.
<ul>
 	<li style="text-align: left;">Activation techniques/exercises are performed with the intent of addressing a muscle exhibiting a reduction in activity (tone) as a result of, or contributing to postural dysfunction.</li>
 	<li style="text-align: left;">Activation techniques/exercises cannot be multi-joint movement patterns due to relative flexibility, altered reciprocal inhibition, and synergistic dominance resulting in compensation patterns.</li>
</ul>
Example, <a href="https://brentbrookbush.com/articles/corrective-exercise-articles/activation/gluteus-medius-activation-progression/" target="_blank">gluteus medius activation</a> involves resisted hip abduction while minimizing the contribution of the TFL via hip extension.

Active stretching is a term used to describe a stretch that involves an active contraction of opposing musculature to lengthen a muscle to its end range. Generally these stretches are held for 2-5 seconds and repeated for 8-15 repetitions.

Adenosine triphosphatase (ATPase): is the enzyme responsible for catalyzing (initiating and accelerating) the decomposition of ATP to ADP.
<ul>
 	<li>This dephosphorylation (breakdown) reaction releases energy for processes like muscular contraction.</li>
</ul>

Adenosine triphosphate (ATP): The molecule that functions as a universal energy-transfer molecule, providing most of the energy associated with muscular contraction and human movement. ATP is composed of an adenine group, a ribose group, and three molecules of inorganic phosphates.
<ul>
 	<li>Energy is provided when hydrolysis results in the cleaving of a phophate group; resulting in adenosine diphosphate, an inorganigic phosphate group, and energy.</li>
</ul>

Algometry - measuring the amount of pressure to result in sensitivity or pain, using an algometer.
<ul>
 	<li>Generally, research uses algometry to establish a minimum pain pressure threshold (PPT), in which a lower PPT implies more sensitivity and pain, and a higher PPT implies less sensitivity and pain. PPT is a common outcome measure in trigger point research.</li>
</ul>
<a href="https://brentbrookbush.com/wp-content/uploads/2019/07/Algometer.jpg"><img class="aligncenter wp-image-140177" src="https://brentbrookbush.com/wp-content/uploads/2019/07/Algometer.jpg" alt="Image of an Algometer" width="500" height="333" /></a>

All-or-none principle - a nerve or muscle cell's response to a stimulus is independent of the strength of the stimulus. If that stimulus exceeds the threshold potential (threshold of an action potential), the nerve or muscle fiber will respond completely; otherwise, there is no response.

Example, when a motor unit in the biceps brachii is stimulated it contracts the same way whether a 10 lb or 50 lb dumbbell is lifted.  It is actually the number of muscle cells and the size of the motor unit that determines force output.

&nbsp;

The transition period between eccentric load and concentric contraction during a repetition of an exercise.  This term is most often used in reference to power/plyometric exercises, in which a shorter amortization phase is believed to be beneficial.  The shorter amortization phase may better use the stored energy from the elastic deformation of connective tissue and enhance synchronization of myotatic (stretch) reflex with maximum voluntary contraction.

Example, the athlete was cued to spend as little time as possible in the bottom of their squat stance (the amortization phase) during a set of box jumps.

Muscles that oppose the prime mover and synergists for a given joint action.

That is, all the muscles that can perform the opposing joint action.

Example: The triceps and anconeus are antagonists during elbow flexion.

An anatomical direction; toward the front

Example, the face is on the anterior aspect of the head

Appendicular Skeleton - referring to the bones the bones of the arms and legs, as well as the bones that support them. This includes the pelvis, clavicle and scapula. There are approximately 126 bones in the appendicular skeleton.
<ul>
 	<li>Etymology - Appendicular, as in appendage, "that which is appended to something as a proper part," 1640s, from <a class="crossreference" href="https://www.etymonline.com/word/append?ref=etymonline_crossreference">append</a> + <a class="crossreference" href="https://www.etymonline.com/word/-age?ref=etymonline_crossreference">-age</a>. - <a href="https://www.etymonline.com/word/appendage" target="_blank" rel="noopener">Etymology Online</a></li>
</ul>
"Appendicular skeleton" is a label referring to a set of bones whose function is distinct from the bones of the "<a href="https://brentbrookbush.com/glossary/axial-skeleton/" target="_blank" rel="noopener">axial skeleton</a>".

A reflexive decrease in muscle activity due to joint dyskinesis.
For example, a reduction in deep cervical flexor activity as a result of cervical spine dyskinesis.

Arthrokinematic Motion - Small amplitude motions between bone surfaces at a joint.  The arthrokinematic motions are roll, glide (slide or translation), spin, compression and distraction (traction). Arthrokinematic motions accompany osteokinematic motions to maintain joint congruence.
<ul>
 	<li>Example, arthrokinematic motion of the talus includes posterior glide on the tibia during ankle dorsiflexion.</li>
</ul>
Synonyms include: arthrokinematics, passive accessory motion, joint play and component motion

&nbsp;

Assessment - is the act of assessing, i.e. determining the importance, size, or value of -

In most cases, the results of an assessment are compared to normative data. If the individual exhibits values that are within normal parameters, it may be assumed that the aspect of health or motion assessed is not contributing to the patient's complaint, symptoms or movement impairment. If the results fall outside of normal parameters, it may indicate that the aspect of health or motion assessed is contributing to, or being affected by the patient/client's complaint, symptoms, or movement impairment. In some cases, the results of an assessment are compared to an "ideal model." In this case, deviations from the ideal are noted as potential issues. For example, deviations noted in the <a title="Introduction to the Overhead Squat Assessment" href="https://brentbrookbush.com/online-courses/articles/assessment/introduction-overhead-squat-assessment/" target="_blank">Overhead Squat Assessment</a> are compared to an "ideal model" of posture and motion.

Assessments used by human movement professionals can be divided into three broad categories:
<ul>
 	<li>"Clear" the Patient/Client for Intervention - These are tests, assessments and evaluations used to determine if a patient/client's issue may improve given the assessing professional's scope, skills, abilities and willingness to treat that individual.
<ul>
 	<li>For example, many of the special tests used in orthopedic medicine assist in determining the level of pathology or likelihood of a particular diagnosis. Certain issues and diagnoses are beyond the scope of the human movement professional, and are better treated by diagnostic professionals in the medical community (physicians, podiatrists, surgeons, etc.). A Calf Squeeze (Thompson) Test is one example, in which a positive sign may indicate a rupture of the Achilles tendon that may be better treated via surgical intervention.</li>
</ul>
</li>
 	<li>Highlight Contraindications - Tests, assessments and evaluations used to stratify risk or preclude a professional from addressing certain tissues, motions or using a particular technique.
<ul>
 	<li>For example, the Vertebral Artery Test (VBI) is often used to determine if high velocity thrust mobilizations (manipulations) are safe for a patient with cervical dysfunction.</li>
</ul>
</li>
 	<li>Refine Exercise/Intervention Selection: Tests, assessments and evaluations used to assist the professional in determining which techniques, modalities and exercises will best address a patient/client's complaints or desired goals.
<ul>
 	<li>Most movement assessments fall into this category. For example, a positive <a href="https://brentbrookbush.com/vimeo_videos/elys-test-rectus-femoris-flexibility-assessment/" target="_blank">Ely's Test</a> may indicate a need to release and/or lengthen the <a href="https://brentbrookbush.com/articles/anatomy-articles/muscular-anatomy/rectus-femoris/" target="_blank">rectus femoris</a>.</li>
</ul>
</li>
</ul>
Note: An assessment, or assessment result, may fall into more than one category. For example, although goniometry is an assessment most often used to Refine Exercise/Intervention Selection, if a range of motion is significantly altered, with an abnormal end-feel, and/or causes the patient or client/pain, the individual may need to be referred to a physician for further testing and Clearance to resume rehab activities.  Further, that same patient may return to the human movement professional with a list of Contraindicated Activities from the physician. - "When in doubt, refer out!"

Axial Skeleton - referring to the bones of the head, neck, trunk and spinal column (does not include pelvis). There are approximately 80 bones in the axial skeleton.
<ul>
 	<li>Etymology - Axial, as in "axis", referring to "imaginary motionless straight line around which a body (such as the Earth) rotates," from Latin axis "axle, pivot, axis of the earth or sky" - <a href="https://www.etymonline.com/word/axis" target="_blank" rel="noopener">Etymology Online</a></li>
</ul>
"Axial skeleton" is a label referring to a set of bones whose function is distinct from the bones of the "<a href="https://brentbrookbush.com/glossary/appendicular-skeleton/" target="_blank" rel="noopener">appendicular skeleton</a>".

Balance - The ability to maintain a body’s center of mass over its base of support. Balance can be static or dynamic.
<ul>
 	<li>For example, maintaining balance is harder on one leg because the center of mass must stay over a much smaller base of support.</li>
</ul>

A ball and socket joint (also called a spheroid joint or spheroidal joint) is a synovial joint in which the rounded or spherical end of one bone fits into a cup-like depression of another bone. The distal bone is capable of motion around an indefinite number of axes, which have one common center. Examples include the hip and shoulder (glenohumeral joint)

Base of support (BoS) - refers to the area beneath an object or person, and the area within the perimeter created by every point of contact that the object or person makes with the supporting surface. This may include the <a href="https://brentbrookbush.com/articles/anatomy-articles/muscular-anatomy/gluteus-maximus/" target="_blank" rel="noopener">glutes</a> of someone sitting on a chair, or the back of someone leaning against a wall.
<ul>
 	<li>For example, during a single leg balance the BoS is the area of the foot in contact with the surface; however, when a person is standing on two feet, the BoS is the area of both feet and the surface between them.</li>
</ul>

Pertaining to both sides

Example, bilateral rows are performed with both arms at the same time.

Case-control Study - a particular form of retrospective study that samples a matched group of people who have, and do not have the outcome being studied. A case-control study is a quasi-experimental design, often used in medicine to aid in determining potential contributing factors (cannot determine causality). In this study type exposure is the dependent variable and outcome is independent.
<ul>
 	<li>Example, in this retrospective case-control, medical records were investigated for trends correlated with cervical pain (1).
<ol>
 	<li>Mäkela, M., Heliövaara, M., Sievers, K., Impivaara, O., Knekt, P., &amp; Aromaa, A. (1991). Prevalence, determinants, and consequences of chronic neck pain in Finland. American journal of epidemiology, 134(11), 1356-1367.</li>
</ol>
</li>
</ul>

An anatomical direction; toward the tail, relative to humans this term is often used to refer to "in the direction of the tale (toward the feet)".

Example, to release the trapezius muscle the therapist used a force directed caudally.

Center of mass (CoM) - an object's mean position of mass; that is, a point that is perfectly surrounded by an equal amount mass in all directions.

Center of gravity (CoG) - point where gravity appears to act. Since the human body is so small compared to the earth, we can assume gravity acts uniformly on the body, and that CoG and CoM are the same.
<ul>
 	<li>Example, the CoM of the human body while lying down or standing straight up is close to our navel. However, it is possible that during a resistance exercise, the combination of the body's weight and the weight of the resistance will place the combined CoM outside the body. For example, during the mid-portion of a <a href="https://brentbrookbush.com/vimeo_videos/back-squat/" target="_blank" rel="noopener">back squat</a> the CoM would be several anterior to the naval.</li>
</ul>

An anatomical direction; toward the head (synonym: cranial)

Example, hip pain was felt with any force directed cephalad.

Cohort Study - a particular form of longitudinal study that samples a cohort (a group of people who share a defining characteristic), performing a cross-section at intervals through-out a period of time. A cohort study is a quasi-experimental design often used in medicine to aid in determining etiology or a cause-and-effect relationship. In this study type exposure is the independent variable and outcome is dependent.
<ul>
 	<li>Example, the study by Cholewicki et al. (1) investigated Yale Varsity Athletes (the cohort) with 2 and 3 year follow up (longitudinal design) and found that trunk muscle response time to off-loading was predictive of future low back injury.</li>
</ul>
<ol>
 	<li><a href="https://brentbrookbush.com/articles/research-corner/core/increased-trunk-muscle-latency-may-cause-rather-than-result-from-low-back-pain/" target="_blank" rel="noopener noreferrer">Cholewicki, J., Silfies, S., Shah, R., Greene, H., Reeves, N. Alvi, K., Goldberg, B. (2005). Delayed trunk muscle reflex responses increase the risk of low back injuries. Spine. 30(23), 2614-2620</a></li>
</ol>

Comparable Sign: A combination of pain, stiffness and/or spasm during examination that is comparable to the patients symptoms.
<ul>
 	<li>One common error made during evaluation with special tests is attention given to any discomfort or pain, rather than attempting to identify the pain/discomfort related to the patient's complaint (concordant/comparable sign). Many special tests purposefully test tissue limits and are at least mildly uncomfortable in every individual. Basing your assessment on positive tests that resulted in "concordant/comparable signs" will improve your chances of arriving at the correct diagnosis.</li>
</ul>

An alternative movement pattern that has been adopted to compensate for dysfunction/impairment in the human movement system.
Example: A lack of calf extensibility may limit dorsiflexion, leading to the knees bowing inward (functional valgus) and excessive forward lean of the torso during a squat.

An arthrokinematic motion - the approximation of joint surfaces; that is, a force that directs one bone surface into another resulting in a reduction in intra-articular volume. Although widely thought of as a "destructive force", it is likely best to consider compression as a naturally occurring, stabilizing force. Any arthrokinematic force in excess (spin, glide, roll, traction) may be viewed as potentially deleterious.

For example, during a squat the femoral head is compressed into the acetabulum by muscular forces, bodyweight and any additional external load.

Concave (Concavity) - Having an outline or surface curved like the interior surface of a bowl or sphere - to cave-in or curve inward.
<ul>
 	<li>Example, the internal surfaces of the pelvis is concave, holding some of the bodies viscera.</li>
</ul>

Concordant Sign - The patient's specific pain, symptom or complaint. 
<ul>
 	<li>One common error made during evaluation with special tests is attention given to any discomfort or pain, rather than attempting to identify the pain/discomfort related to the patient's complaint (concordant/comparable sign). Many special tests purposefully test tissue limits and are at least mildly uncomfortable in every individual. Basing your assessment on positive tests that resulted in "concordant/comparable signs" will improve your chances of arriving at the correct diagnosis.</li>
</ul>

Conductivity: Stimulation results in more than a local effect (1).
<ul>
 	<li>For example, in a muscle cell the stimulation of a motor endplate results in a change in cell membrane polarity that rapidly propagates (is conducted) along the entire length of the muscle cell, stimulating all sacromere.</li>
</ul>
<ol>
 	<li>Saladin, K. (2012). Anatomy &amp; Physiology: The unity of form and function. (6th ed.). New York: McGraw-Hill.</li>
</ol>

A condyloid joint (also called condylar, bicondylar, ellipsoid, or ellipsoidal) is an ovoid articular surface, or condyle, that is received into an elliptical cavity.  These joints permit movement in two planes.  Examples include the knee, metacarpophalangeal joints and metatarsophalangeal joints.

Connective Tissue Cell - One of the four basic types of animal tissue, consisting mostly fibers and ground substance.  These cells are specialized to binds organs together, holds them in place, protect them from external forces, and may fill space in the body's cavities.

Example, the body's muscles are enclosed in durable connective tissue sheets known as the "epimysium", "perimysium", and "endomysium," which and in support and transmitting force.
<ol>
 	<li>Saladin, K. (2014). Anatomy &amp; physiology: The unity of form and function. McGraw-Hill Higher Education, New York. ISBN: 9780073403717</li>
</ol>

Contractility: The ability to shorten (1).
<ul>
 	<li>Contractility: Muscle cells are unique in the amount they can shorten when stimulated; this is this largerly due to the highly organized and unique arrangement of myofilaments (actin and myosin).</li>
</ul>
<ol>
 	<li>Saladin, K. (2012). Anatomy &amp; Physiology: The unity of form and function. (6th ed.). New York: McGraw-Hill.</li>
</ol>

Pertaining to the opposite side

Example, the external oblique muscle performs contralateral rotation; rotation to the opposite side.

Convex (Convexity) - Having an outline or surface curved like the exterior of a circle or sphere - to bulge or curve outward.
<ul>
 	<li>Example, the top of your head is shaped by the convex exterior surface of your skull.</li>
</ul>

Correlational Research - Non-experimental <a href="https://www.questionpro.com/blog/what-is-research/">research</a> method in which the statistical relationship between two variables is investigated.
<ul>
 	<li>In this research by Kwon et al., a correlation was noted between a decrease in extensibility during a hamstring length test (goniometry) and current knee pain (1).</li>
</ul>
<ol>
 	<li><a href="https://brentbrookbush.com/articles/research-corner/knee/correlation-patellofemoral-pain-syndrome-pfps-hamstring-activity/" target="_blank" rel="noopener">Kwon O, Yun M, and Lee W. (2014). Correlation between intrinsic patellofemoral pain syndrome in young adults and lower extremity biomechanics. J. Phys. Ther. Sci. 26: 961-964</a></li>
</ol>

Counter-nutation - posterior rotation of sacrum relative to ilium, and/or anterior rotation of ilium relative to sacrum.
<ul>
 	<li>The pelvic floor muscles are examples of muscle that may counter-nutate the sacrum.</li>
</ul>
[caption id="attachment_126335" align="aligncenter" width="400"]<a href="https://brentbrookbush.com/wp-content/uploads/2018/10/Nutation.png"><img class=" wp-image-126335" src="https://brentbrookbush.com/wp-content/uploads/2018/10/Nutation.png" alt="Nutation and Counter-nutation of the Sacroiliac Joint" width="400" height="967" /></a> Nutation and Counter-nutation of the Sacroiliac Joint[/caption]

&nbsp;

Crossover (Study) Design - A type of longitudinal, repeated measures quasi-experimental design in which each group receives both treatments, but at different times. It is named "crossover" due to the patients "crossing-over" to the other treatment or sham group after a specified period of time.
<ul>
 	<li>This type of study has the advantage of every individual serving as their own control, which may reduce the influence of confounding variables.</li>
 	<li>Unfortunately, the design itself introduces the chances that anyone receiving the experimental variable in the first period will continue to be effected in the second period.</li>
</ul>
In a study by Senna et al., a cross-over design was used to investigate the difference load made on inter-set rest intervals (1).
<ol>
 	<li><a href="https://brentbrookbush.com/articles/research-corner/strength-training-research-corner/heavy-vs-light-load-single-joint-exercise-performance-with-different-rest-periods/" target="_blank" rel="noopener">Senna, G.W., Rodrigues, B.M., Sandy, Scudese, Bianco, A, &amp; Dantas, E.H.M. (2017). Heavy vs light load single-joint exercise performance with different intervals. Journal of Human Kinetics, 58, 197-206. </a></li>
</ol>

Cross-sectional Study - a research design that involves gathering data from a population or representative subset at a specific point in time.
<ul>
 	<li>Example, the study by Karimi-Mobarake et al.(1) investigated the prevalence of genu varum and genu valgum among school children 7-11 years old in Iran.</li>
</ul>
<ol>
 	<li><a href="https://brentbrookbush.com/articles/research-corner/knee/low-prevalence-of-genu-varum-and-valgum-among-elementary-school-children/" target="_blank" rel="noopener noreferrer">Karimi-Mobarake, M., Kashefipour, A., Yousfnejad, Z. The prevalence of genu varum and genu valgum in primary school children in Iran 2003-2004. (2005) Journal of Medical Science 5(1). 52-54</a></li>
</ol>

Cytokine - A broad and loose category of small proteins that act through receptors, and are especially important to immune function (inflammation).
<ul>
 	<li>Cytokines include substances such as interferon, interleukin, and growth factors, which are secreted by certain cells of the immune system and have an effect on other cells. Their definite distinction from hormones is a topic of continued research.</li>
</ul>
&nbsp;

Dependent variable - in research, this is the variable that is changed by the independent variable, most often this is the "outcome" of the study.
<ul>
 	<li>Example, in the study by Cleland et al. (1), the independent variable is "thoracic manipulation," and the dependent variable is "lower trapezius muscle strength."</li>
</ul>
<ol>
 	<li><a href="https://brentbrookbush.com/articles/research-corner/short-term-effects-lower-thoracic-manipulation-lower-trapezius-muscle-strength/" target="_blank" rel="noopener noreferrer">Cleland J, Selleck B, Stowell T, Brown L, Alberini S, St. Cyr H, Caron T. Short-term Effects of Thoracic Manipulation on Lower Trapezius Muscle Strength.  Journal of Manual &amp; Manipulative Therapy. 2004; 12(2): 82-90</a></li>
</ol>

An anatomical direction; further from the trunk or center of the body

Example, the foot is at the distal end of the leg.

An arthrokinematic motion - a force applied to a body part that may result in the separation of joint surfaces, a reduction in intra-articular pressure, and/or an increase in intra-articlar space.

For example, to hang from one's hands (i.g. in preparation for a pull-up) results in a traction force on the glenohumeral joint (shoulder).

An anatomical term of location; back or upper surface

Example, shoe laces may compress tissues on the dorsal surface of the foot

The "drawing-in" maneuver is a common cue used during exercise and rehabilitation programs. A light contraction of the <a href="https://brentbrookbush.com/articles/muscular-anatomy/transverse-abdominis/" target="_blank" rel="noopener">transverse abominis</a> (and potentially the entire <a href="https://brentbrookbush.com/articles/corrective-exercise-articles/core-subsystems/intrinsic-stabilization-subsystem/" target="_blank" rel="noopener">intrinsic stabilization subsystem</a>) achieved by gently pulling the lower abdominal region away from one's waist band. This should have minimal effect on breathing, and should not be confused with a maximal contraction of the <a href="https://brentbrookbush.com/articles/muscular-anatomy/transverse-abdominis/" target="_blank" rel="noopener">transverse abdominis</a> resulting in a "vacuum pose".
<ul>
 	<li>Research often refers to this maneuver as the "abdominal drawing-in maneuver"; abbreviated ADIM.</li>
</ul>
Development and introduction of this cue into practice is based on the pivotal research and resulting text:
<ol>
 	<li>Carolyn Richardson, Paul Hodges, Julie Hides. Therapeutic Exercise for Lumbo Pelvic Stabilization – A Motor Control Approach for the Treatment and Prevention of Low Back Pain: 2nd Edition (c) Elsevier Limited, 2004</li>
</ol>

Faulty or abnormal movement; an alteration of normal kinematics.

For example, joint stiffness or a reduction in arthrokinematics motion that results in limited osteokinematic range of motion - inadequate inferior glide of the femoral head resulting in limited abduction of the hip.

The seeping into, or abnormal collection of fluid in a body cavity.

For example, knee effusion describes swelling within the knee joint.

Note: the word "effusion" is used differently in medicine than it is used in reference to the movement (seeping out) of liquids and gases, for example in chemistry.

&nbsp;

A trait of body tissues that allows a tissue to return to its resting length or state after deformation or stretch.
Example:  Muscle is elastic tissue; many muscles will return to their resting length after being stretched to 150% of that length without any appreciable change in tissue quality.

Elasticity: Elasticity refers to the ability of a cell to return to its resting length after being stretched/lengthened.
<ul>
 	<li>Note: this term is often confused with extensibility. Elasticity is not the ability to stretch; it is the ability to return to normal length after being stretched. Muscle tissue, connective tissue and even nerve tissue have varying levels of elasticity.</li>
</ul>
<ol>
 	<li>Saladin, K. (2012). Anatomy &amp; Physiology: The unity of form and function. (6th ed.). New York: McGraw-Hill.</li>
</ol>

Epithelial cell - One of the four basic cell types, found lining the body's cavities, blood vessels, organs and constitutes most gland tissue.  These cells are specialized to aid with absorption, secretion, or act as a barrier from foreign objects.
<ol>
 	<li>Saladin, K. S., &amp; Miller, L. (1998). Anatomy &amp; physiology. New York (NY): WCB/McGraw-Hill.</li>
</ol>

Equilibrium - a state in which opposing forces or influences are balanced.
<ul>
 	<li>For example, to maintain a neutral trunk while pushing or pulling a weight in one hand, your core musculature must balance the force by creating an equal amount of force in the opposite direction.</li>
</ul>

The study of causation, or origination. The word is commonly used in the medical professions, where it may refer to the study of why things occur, or the reason behind why things act a certain way.

For example, the etiology of low back pain is a complex subject, with multiple contributing factors and various structures implicated.

<div class="gs_citr" tabindex="0">Evidence-based medicine (practice) is the integration of best research evidence with clinical expertise and patient(client) values (2)."</div>
<ul>
 	<li class="gs_citr" tabindex="0">...the conscientious, explicit and judicious use of current best evidence in making decisions about the care of individual patients (clients).  It involves the integration of at least (a) clinical expertise/expert opinion, (b) external scientific evidence, and (c) client/patient/caregiver perspectives to provide high-quality services reflecting the interests, values, needs, and choices of the individuals we serve (1).</li>
</ul>
&nbsp;
<ol>
 	<li id="gs_cit1" class="gs_citr" tabindex="0">Sackett, D. L., Rosenberg, W. M., Gray, J. M., Haynes, R. B., &amp; Richardson, W. S. (1996). Evidence based medicine: what it is and what it isn't. Bmj, 312(7023), 71-72.</li>
 	<li class="gs_citr" tabindex="0">Sackett D et al. Evidence-Based Medicine: How to Practice and Teach EBM, 2nd edition. Churchill Livingstone, Edinburgh, 2000, p.1</li>
</ol>

Excitability: The ability of a cell to change in membrane conductance as a response to stimulation.

<ul>
 	<li>For example, muscle cells are specialized to react to a change in membrane potential with contraction, where as nerve cells are specialized to propagate a change in membrane potential along there axons and communicate that message to other tissues via neurotransmitters.
</li>
</ul>
<ol>
 	<li>Saladin, K. (2012). Anatomy &amp; Physiology: The unity of form and function. (6th ed.). New York: McGraw-Hill.</li>
</ol>

Excitation threshold: The level that a depolarization must reach for an action potential to occur.
<ul>
 	<li>The excitation threshold is a contributing factor to the "all-or-none" response of muscle and nerves cells to a stimulus.</li>
</ul>

Exercise Progression - Modification of an exercise with the intent of promoting adaptation by increasing demand. This can be accomplished by increasing reps, load, tempo, range of motion, complexity, and/or challenge to an individual's stability.
<ul>
 	<li>Because load, reps, tempo and complexity are often explicitly noted, the term "exercise progression" is most often used throughout Brookbush Institute (BI) content to refer to an exercise, or series of exercises that make it harder to maintain stability with good form.
<ul>
 	<li>Sample Exercise Progression: <a href="https://brentbrookbush.com/vimeo_videos/kneeling-chop-pattern/" target="_blank" rel="noopener">Kneeling Chop</a> to <a href="https://brentbrookbush.com/vimeo_videos/static-standing-chop-pattern/" target="_blank" rel="noopener">Standing Chop</a> to <a href="https://brentbrookbush.com/vimeo_videos/single-leg-chop-pattern/" target="_blank" rel="noopener">Single-leg Chop</a></li>
</ul>
</li>
</ul>

Exercise regression - The opposite of progression; that is, modification of an exercise with the intent of reducing demand. This can be accomplished by decreasing reps, load, tempo, range of motion, complexity, and/or challenge to an individual's stability. Generally, regressions are used to modify an exercise to the client's current level of ability, with the intent of improving form, motor learning and retention.
<ul>
 	<li>Because load, reps, tempo and complexity are often explicitly noted, the term "exercise regression" is most often used throughout Brookbush Institute (BI) content to refer to an exercise or series of exercises that make it easier to maintain stability with good form.
<ul>
 	<li>Sample Exercise Regression: <a href="https://brentbrookbush.com/vimeo_videos/single-leg-chop-pattern/" target="_blank" rel="noopener">Single-leg Chop</a> to <a href="https://brentbrookbush.com/vimeo_videos/static-standing-chop-pattern/" target="_blank" rel="noopener">Standing Chop</a> to <a href="https://brentbrookbush.com/vimeo_videos/kneeling-chop-pattern/" target="_blank" rel="noopener">Kneeling Chop</a></li>
</ul>
</li>
</ul>

Experimental Research - Studies in which the researchers introduce the variable to be studied, with the intent of observing the outcome. This is different than observational research which observes the effect of a variable already present. Many texts also assert that experimental research should include randomization and ideally a control group, as is seen in Randomized Control Trials. Studies in which the variable is introduced by the researchers, but participants are not randomized may be considered Quasi-experimental research.
<ul>
 	<li>In this study by Esformes, the experimental variable was squat depth and the outcome measures observed were various performance measures related to power (1).</li>
</ul>
<ol>
 	<li><a href="https://brookbushinstitute.com/article/back-squat-depth-lower-body-post-activation-potentiation/" target="_blank" rel="noopener">Esformes, J., &amp; Bampouras, T. (2013). Effect of back squat depth on lower-body postactivation potentiation. Journal of Strength and Conditioning Research, 27(11), 2997-3000.</a></li>
</ol>
&nbsp;

Extensibility: The ability of a cell to be stretched or lengthened without damage (1).
<ul>
 	<li>For example, most cells would rupture with even a modest stretch, but muscles can stretch up to 3 times their contracted length.</li>
</ul>
<ol>
 	<li>Saladin, K. (2012). Anatomy &amp; Physiology: The unity of form and function. (6th ed.). New York: McGraw-Hill.</li>
</ol>

False Negative - the proportion of negatives in a group that were assessed incorrectly (assessed as negative when the patient was actually positive)
<ul>
 	<li>Test Results: Although most tests/assessments result in either a positive or negative, the accuracy of a test is dependent on the number  of positives and negatives that are correct. Therefore, when the accuracy of a test is determined, their are 4 possible results, because a positive or negative result could be right (true) or wrong (false).</li>
</ul>

False Positive - the proportion of positives in a group that were assessed incorrectly (assessed as positive when the patient was actually negative)
<ul>
 	<li>Test Results: Although most tests/assessments result in either a positive or negative, the accuracy of a test is dependent on the number  of positives and negatives that are correct. Therefore, when the accuracy of a test is determined, their are 4 possible results, because a positive or negative result could be right (true) or wrong (false).</li>
</ul>

The function of fascia is to transmit force, provide support, and protect tissues. Fascia can effect motion by:
Transmitting force from one or more muscles (example: the thoracolumbar fascia)
Restricting motion in cases of adaptive shortening and/or adhesion to proximal structures (example: iliotibial band in cases of lower-leg dysfunction)
Elastic recoil after stretching can contribute to force production (example: plyometric exercise)

Note: There is evidence that fascia may house more receptors related to human movement than other tissues. In this way fascia may act as a motherboard for the nervous system

The fascial system does not contract or develop trigger points, and its capacity to adapt to stretching and or strengthening exercise is limited, especially when compared to the adaptive capacity of muscle tissue.

Fibromyalgia - A loosely defined diagnosis that is associated with a combination of widespread pain in combination with 2) tenderness at 11 or more of the 18 specific tender point sites. Consideration may also be given to the presence of psychosocial stressors and inflammatory disease in the patients history. Newer research suggests that fibromyalgia may be at least in part due to central sensitization of myofascial pain, often associated with trigger points (1 - 4).
<ol>
 	<li>Wolfe, F. (2018). Fibromyalgia Syndrome and Fibromyalgia Syndrome Criteria: Problems in Definition and Validity. Fibromyalgia Syndrome and Widespread Pain: From Construction to Relevant Recognition.</li>
 	<li>Wolfe, F., Smythe, H. A., Yunus, M. B., Bennett, R. M., Bombardier, C., Goldenberg, D. L., ... &amp; Fam, A. G. (1990). The American College of Rheumatology 1990 criteria for the classification of fibromyalgia. Arthritis &amp; Rheumatism: Official Journal of the American College of Rheumatology, 33(2), 160-172.</li>
 	<li>Alonso-Blanco, C., Fernandez-de-las-Penas, C., Morales-Cabezas, M., Zarco-Moreno, P., Ge, H. Y., &amp; Florez-García, M. (2011). Multiple active myofascial trigger points reproduce the overall spontaneous pain pattern in women with fibromyalgia and are related to widespread mechanical hypersensitivity. The Clinical journal of pain, 27(5), 405-413.</li>
 	<li>Staud, R., Nagel, S., Robinson, M. E., &amp; Price, D. D. (2009). Enhanced central pain processing of fibromyalgia patients is maintained by muscle afferent input: a randomized, double-blind, placebo-controlled study. PAIN®, 145(1-2), 96-104.</li>
</ol>
&nbsp;

Muscles that act to reduce or prevent movement at proximal joints to improve force transmission.
Example: The muscles of the core are important fixators; reducing motion of the spine/trunk to enhance force transmission between the extremities and environment.

An increase in joint stability via compressive forces resulting from muscular contraction and increased tension in fascial structures (1,2).
<ul>
 	<li>This term is most often used in reference to core intrinsic stabilizers, the thoracolumbar fascia and the sacroiliac joint; however, force closure and form closure have been mentioned in the literature referring to other joints.</li>
 	<li>Related term: Form closure</li>
</ul>
<ol>
 	<li>Andry Vleeming, Vert Mooney, Rob Stoeckart. Movement, Stability &amp; Lumbopelvic Pain: <a class="glossaryLink " title="Glossary: Integration" href="https://brentbrookbush.com/glossary/integration/" target="_blank" rel="noopener noreferrer" data-cmtooltip="&lt;div class=glossaryItemTitle&gt;Integration&lt;/div&gt;&lt;div class=glossaryItemBody&gt;Making a whole of parts.&lt;br /&gt;&lt;br /&gt;Example, The Brookbush Institute uses an integrative approach to explaining and addressing human movement.&lt;/div&gt;">Integration</a> of Research and Therapy. (c) 2007 Elsevier Limited</li>
 	<li id="gs_cit1" class="gs_citr" tabindex="0">Vleeming, A., Pool-Goudzwaard, A. L., Stoeckart, R., van Wingerden, J. P., &amp; Snijders, C. J. (1995). The Posterior Layer of the Thoracolumbar Fascia| Its Function in Load Transfer From Spine to Legs. Spine, 20(7), 753-758.</li>
</ol>

The relative contribution of joint shape and structure to the stability of a joint (1,2).
<ul>
 	<li>This term is most often used in reference to the "rough" articulating surfaces of the sacroiliac joint and the wedge shape of the sacrum; however, force closure and form closure have been mentioned in the literature referring to other joints.</li>
 	<li>Related term: Force closure</li>
</ul>
<ol>
 	<li>Andry Vleeming, Vert Mooney, Rob Stoeckart. Movement, Stability &amp; Lumbopelvic Pain: <a class="glossaryLink " title="Glossary: Integration" href="https://brentbrookbush.com/glossary/integration/" target="_blank" rel="noopener noreferrer" data-cmtooltip="&lt;div class=glossaryItemTitle&gt;Integration&lt;/div&gt;&lt;div class=glossaryItemBody&gt;Making a whole of parts.&lt;br /&gt;&lt;br /&gt;Example, The Brookbush Institute uses an integrative approach to explaining and addressing human movement.&lt;/div&gt;">Integration</a> of Research and Therapy. (c) 2007 Elsevier Limited</li>
 	<li id="gs_cit1" class="gs_citr" tabindex="0">Vleeming, A., Pool-Goudzwaard, A. L., Stoeckart, R., van Wingerden, J. P., &amp; Snijders, C. J. (1995). The Posterior Layer of the Thoracolumbar Fascia| Its Function in Load Transfer From Spine to Legs. Spine, 20(7), 753-758.</li>
</ol>

An arthrokinematic motion - linear motion across a joint surface parallel to the plane of the adjacent joint surface, just as your posterior moves relative to a "slide" in a park.

For example, the glide of facet joint in the spine during spinal flexion and extension, or the posterior glide of the humeral head that must accompany anterior roll to maintain congruence with glenoid fossa during shoulder horizontal adduction.

A plane joint (also called an arthrodial joint, gliding joint or plane articulation) is a synovial joint which allows only gliding movement in the plane of the articular surfaces. The opposed surfaces of the bones are flat or almost flat, with movement generally limited by tight capsules and ligaments. Plane joints are numerous, are most often small, and allow very little motion.  Examples include the carpal joints of the wrist, the tarsal joints of the ankle, and the facet joints of the spine.

"...refers to the measurement of angles, in particular the measurement of angles created at human joints by the bones of the body (1).

&nbsp;
<ol>
 	<li>Cynthia C. Norkin, D. Joyce White. Measurement of Joint Motion: A Guide to Goniometry 3rd Edition. Copyright (C) 2003 by F.A. Davis Company</li>
</ol>

Ground reaction force (GRF) - The force exerted by the ground on the body in contact with it.

For example, when a runner's foot strikes the ground with a force equal to the mass of the individual times their acceleration due to gravity, momentum and muscular exertion, the ground exerts an equal and opposite force on the runner's foot.
<ul>
 	<li>GRF is often measured in research studies using force plates as a means of quantitatively measuring the force generated by an individual.</li>
</ul>

H-Band - Refers to the central zone of a sarcomere that looks lighter under a microscope.  This area of the sarcomere is a lighter portion of the A-band where there is no overlap between the thinner filaments (actin), and the thicker filaments (myosin).
<ul>
 	<li>Example, when a muscle contracts, actin and myosin cross-bridging occurs in the region of the A-band until the H-band is reached where no overlap occurs.</li>
</ul>
<ol>
 	<li>Saladin, K. (2014). Anatomy &amp; physiology: The unity of form and function. McGraw-Hill Higher Education, New York. ISBN: 9780073403717</li>
</ol>

A hinge joint (also called a ginglymus) is a synovial joint in which the articular surfaces fit one another in a way that only permits motion in one plane. Examples include the elbow, the knee (unless considered a condyloid joint) and the interphalangeal joints.

Holism (holistic) (biological holism) - (from Greek holos "all, whole, entire") is the idea that systems and their properties should be viewed as wholes, not just as a collection of parts.
<ul>
 	<li>Summarized by Aristotle in his "Metaphysics": "The whole is more than the sum of its parts". However, the term "holism" was introduced into language by the South African statesman Jan Smuts as recently as 1926. (Smuts J. C. 1987 [1926]. Holism and evolution. Cape Town: N &amp; S Press.)</li>
</ul>
Example: The Brookbush Institute promotes a holistic approach to human movement science, in which the muscular, fascial, articular and neural systems are not viewed as separable and all proximal segments are considered.

Hormone: Chemical messengers produced by the endocrine system, transported via tissue fluids such as blood, to stimulate cells to "act."
<ul>
 	<li>Example: Growth hormone is secreted by the pituitary gland in the brain; stimulating growth, cell reproduction and cell regeneration in certain types of cells</li>
</ul>
The English physician E. H. Starling discovered in collaboration with the physiologist W. M. Bayliss secretin, the first hormone, in 1902. (1).
<ol>
 	<li>Henriksen, J. H., &amp; de Muckadell, O. S. (2000). Secretin, its discovery, and the introduction of the hormone concept. Scandinavian journal of clinical and laboratory investigation, 60(6), 463-472.</li>
</ol>

A range of motion achieved by the patient/client that is more than normal.
<ul>
 	<li>Note: Both hyper-mobility and hypo-mobility may adversely affect motion and may lead to deleterious effects on joints and soft tissue over time. There is no evidence to suggest that more or less flexibility than normal is beneficial.</li>
</ul>
Example: If an individual can place their forehead on their knees they are likely hypermobile at one, if not several joints

Example 2: 110° of shoulder external rotation would be considered hyper-mobile.

Hyperplasia is an increase in organic tissue size due to an adaptive increase in the number of cells per organ.
<ul>
 	<li>Although muscle hyperplasia has been noted in some animals, human muscle tissue does not seem to have this adaptive ability.</li>
</ul>

A condition of excessive tone of the skeletal muscles; increased resistance of muscle to passive stretching.  May be related to increased neural drive, synergistic dominance, trigger points, reflexive over-activity, and/or muscle length.
Example:  Individuals who exhibit ankle eversion and abduction during an overhead squat assessment likely have hypertonic fibularis (peroneal) muscles.

Muscular hypertrophy is an increase in muscle mass/size due to increase in the volume and cross-sectional area (CSA) of individual muscle cells. The increase in cross-sectional area can be attributed to an an increase in contractile proteins and structural elements (myofibrillar hypertophy), as well as an increase in glycogen storage and elements related to metabolism (sarcoplasmic hypertophy). Hypertrophy is an adaptation of both cardiac and skeletal muscle fibers in response to progressive increases in workload.
<ul>
 	<li>Note: Hypertrophy is not hyperplasia. Hyperplasia is an increase in muscle size due to an adaptive increase in the number of muscle fibers/cells per muscle. This type of adaptation does not occur in human muscle tissue.</li>
</ul>

A range of motion achieved by a patient/client that is less than normal.
<ul>
 	<li>Note: Both hyper-mobility and hypo-mobility may adversely affect motion and may lead to deleterious effects on joints and soft tissue over time. There is no evidence to suggest that more or less flexibility than normal is beneficial.</li>
</ul>
Example: If the end range of shoulder external rotation is reached and measured as 75° during goniometric assessment, the client/patient is exhibiting hypomobility of the glenohumeral joint (shoulder).

Hypothesis - a proposed explanation for a phenomenon; "scientific hypotheses" are generally constructed in a way that is testable or falsifiable.
<ul>
 	<li>Example: The hypothesis, "excessive knee valgus may be correlated with future knee pain and injury," has been the subject of several studies published over the last decade.</li>
</ul>

Diminished tone of skeletal muscles; diminished resistance of muscles to passive stretching.   May be related to inhibition, reciprocal inhibition, arthrokinematics inhibition and/or  increased resting length of muscle.
Example:  If your knees cave (hip adduction) during a squat or leg-press it is likely that your gluteus medius is hypotonic.

I-Band - Refers to the part of the muscle cell that looks lighter under a microscope.  This area of the cell is lighter due to parallel arrangement of thinner filaments (actin), and no overlap with the thicker filaments (myosin).
<ul>
 	<li>As a muscle contracts, the I-bands will decrease in width and move closer to one another.</li>
</ul>
<ol>
 	<li>Saladin, K. (2014). Anatomy &amp; physiology: The unity of form and function. McGraw-Hill Higher Education, New York. ISBN: 9780073403717</li>
</ol>

Independent variable - in research, this is the variable or phenomenon being manipulated in the study.
<ul>
 	<li>Example, in the study by Ghanbari et al. (1), the independent variable is "knee joint mobilization", the dependent variable is "quadriceps muscle strength."</li>
</ul>
<ol>
 	<li><a href="https://brentbrookbush.com/articles/research-corner/effect-knee-joint-mobilization-quadriceps-muscle-strength/" target="_blank" rel="noopener noreferrer">Ghanbari A. and Kamalgharibi S. (2013). Effect of knee joint mobilization on quadriceps muscle strength. International Journal of Health and Rehabilitation Sciences. 2(4): 186-191</a></li>
</ol>

An anatomical direction; toward the bottom (below)

Example, the mouth is inferior to the eyes

A reduction in neural drive, muscular activity, and or force output due to altered neuromuscular reflex.  Alterations in neuromuscular reflex may occur due to increases in muscle length (hypothesis: increased excitation threshold), altered reciprocal inhibition in response to increased antagonist tone, and or alterations in joint motion (arthrokinematics inhibition).

Making a whole of parts.

Example, The Brookbush Institute uses an integrative approach to explaining and addressing human movement.

Intermuscular Coordination - Optimal timing and motor unit recruitment of agonists, antagonists, synergists, neutralizers, stabilizers and fixators.

Example: Role of Muscles during Hip Extension
<ul>
 	<li><a class="glossaryLink " style="box-sizing: border-box; font-family: roboto; color: #000000 !important; font-size: 15px; outline: none; background: transparent; border-bottom: 1px dotted #000000 !important; text-decoration: none;" title="Glossary: Prime Mover" href="https://brentbrookbush.com/glossary/prime-mover/" target="_blank" rel="noopener" data-cmtooltip="&lt;div class=glossaryItemTitle&gt;Prime Mover&lt;/div&gt;The muscle most responsible for a joint action under load -&lt;br /&gt;&lt;br /&gt;That is, the muscle that can produce the most force for a given joint action. Often this term is used synonymously with the term agonist. The prime mover as defined above, may or may not be the most active muscle for a joint action during activities of daily living.&lt;br /&gt;&lt;br /&gt;Example: the gluteus maximus is the most powerful hip extensor and therefore the prime mover; however, the hamstrings are likely the most active hip extensors during low level activities like walking or standing.">Prime Mover</a>:  <a href="https://player.vimeo.com/external/82855344.hd.mp4?s=54c3e7d98fb9d4e0af8d282c85ba9b3e">Gluteus maximus</a></li>
 	<li><a class="glossaryLink " style="box-sizing: border-box; font-family: roboto; color: #000000 !important; font-size: 15px; outline: none; background: transparent; border-bottom: 1px dotted #000000 !important; text-decoration: none;" title="Glossary: Synergists" href="https://brentbrookbush.com/glossary/synergists/" target="_blank" rel="noopener" data-cmtooltip="&lt;div class=glossaryItemTitle&gt;Synergists&lt;/div&gt;Muscles that assist the prime mover in performing a joint action.&lt;br /&gt;&lt;br /&gt;That is, all muscles that can perform a joint action that are not the prime mover, are termed synergists.&lt;br /&gt;Example: The rectus abdominis is the prime mover of spinal flexion. All other muscles that can perform spinal flexion are synergists including – external obliques, internal obliques and psoas.">Synergists</a>: <a href="https://brentbrookbush.com/articles/muscular-anatomy/biceps-femoris/">Biceps femoris (long head)</a>, <a href="https://brentbrookbush.com/articles/muscular-anatomy/semitendinosus-and-semimembranosus/">semitendinosus, semimembranosus</a>, <a href="https://brentbrookbush.com/articles/muscular-anatomy/adductors/">posterior head of adductor magnus</a></li>
 	<li><a class="glossaryLink " style="box-sizing: border-box; font-family: roboto; color: #000000 !important; font-size: 15px; outline: none; background: transparent; border-bottom: 1px dotted #000000 !important; text-decoration: none;" title="Glossary: Antagonist" href="https://brentbrookbush.com/glossary/antagonists/" target="_blank" rel="noopener" data-cmtooltip="&lt;div class=glossaryItemTitle&gt;Antagonist&lt;/div&gt;Muscles that oppose the prime mover and synergists for a given joint action.&lt;br /&gt;&lt;br /&gt;That is, all the muscles that can perform the opposing joint action.&lt;br /&gt;&lt;br /&gt;Example: The triceps and anconeus are antagonists during elbow flexion.">Antagonists</a>: <a href="https://brentbrookbush.com/articles/muscular-anatomy/psoas/">Psoas</a>, <a href="https://brentbrookbush.com/articles/muscular-anatomy/iliacus/">iliacus</a>, <a href="https://brentbrookbush.com/articles/muscular-anatomy/tensor-fascia-latae-tfl/">tensor fascia latae</a> (TFL),<a href="https://brentbrookbush.com/articles/muscular-anatomy/rectus-femoris/"> rectus femoris</a>, <a href="https://brentbrookbush.com/articles/muscular-anatomy/adductors/">anterior adductors (especially pectineus)</a>, <a href="https://brentbrookbush.com/articles/muscular-anatomy/sartorius/">sartorius</a></li>
 	<li><a class="glossaryLink " style="box-sizing: border-box; font-family: roboto; color: #000000 !important; font-size: 15px; outline: none; background: transparent; border-bottom: 1px dotted #000000 !important; text-decoration: none;" title="Glossary: Neutralizer" href="https://brentbrookbush.com/glossary/neutralizers/" target="_blank" rel="noopener" data-cmtooltip="&lt;div class=glossaryItemTitle&gt;Neutralizer&lt;/div&gt;Muscles that oppose unwanted joint motions created by the prime mover and/or synergists, and/or muscles that prevent unwanted ancillary motion.&lt;br /&gt;Example: The teres minor and infraspinatus neutralize the internal rotation force created by the pectoralis major during horizontal adduction of the shoulder.">Neutralizers</a>: <a href="https://brentbrookbush.com/articles/muscular-anatomy/gluteus-minimus/">Gluteus minimus</a> and <a href="https://brentbrookbush.com/articles/muscular-anatomy/gluteus-medius/">anterior fibers of gluteus medius</a> neutralize external rotation force of <a href="https://brentbrookbush.com/articles/muscular-anatomy/gluteus-maximus/">gluteus maximus</a></li>
 	<li><a class="glossaryLink " style="box-sizing: border-box; font-family: roboto; color: #000000 !important; font-size: 15px; outline: none; background: transparent; border-bottom: 1px dotted #000000 !important; text-decoration: none;" title="Glossary: Stabilizer" href="https://brentbrookbush.com/glossary/stabilizers/" target="_blank" rel="noopener" data-cmtooltip="&lt;div class=glossaryItemTitle&gt;Stabilizer&lt;/div&gt;Muscles whose primary role is to improve arthrokinematics by maintaining optimal alignment of joint surfaces.&lt;br /&gt;&lt;br /&gt;Most often these muscles are the most intrinsic muscles of a joint, have a larger percentage of Type I muscle fibers and are rich in proprioceptors.&lt;br /&gt;Example: The muscles of the rotator cuff act as stabilizers for most shoulder motions.">Stabilizers</a>: <a href="https://brentbrookbush.com/articles/muscular-anatomy/deep-rotators-of-the-hip/">Deep rotators of hip</a></li>
 	<li><a class="glossaryLink " style="box-sizing: border-box; font-family: roboto; color: #000000 !important; font-size: 15px; outline: none; background: transparent; border-bottom: 1px dotted #000000 !important; text-decoration: none;" title="Glossary: Fixator" href="https://brentbrookbush.com/glossary/fixators/" target="_blank" rel="noopener" data-cmtooltip="&lt;div class=glossaryItemTitle&gt;Fixator&lt;/div&gt;Muscles that act to reduce or prevent movement at proximal joints to improve force transmission.&lt;br /&gt;Example: The muscles of the core are important fixators; reducing motion of the spine/trunk to enhance force transmission between the extremities and environment.">Fixators</a>: <a href="https://brentbrookbush.com/articles/core-subsystems/intrinsic-stabilization-subsystem/">Intrinsic stabilization subsystem</a>, <a href="https://brentbrookbush.com/articles/muscular-anatomy/rectus-abdominis/">rectus abdominis</a>, <a href="https://brentbrookbush.com/articles/muscular-anatomy/internal-obliques/">internal</a> and <a href="https://brentbrookbush.com/articles/muscular-anatomy/external-obliques/">external obliques</a>, <a href="https://brentbrookbush.com/articles/muscular-anatomy/quadratus-lumborum/">quadratus lumborum</a>, <a href="https://brentbrookbush.com/articles/muscular-anatomy/erector-spinae/">erector spinae</a></li>
</ul>
&nbsp;

Example from: <a href="https://brentbrookbush.com/articles/anatomy-articles/introduction-to-functional-anatomy/kinesiology-of-the-hip/" target="_blank" rel="noopener">Introduction to Functional Anatomy: Kinesiology of the Hip</a>

Intramuscular coordination refers to the coordinated recruitment of motor units within a single muscle. This concept is used to explain increases in maximal strength and power; however, the coordinated and sequential recruitment of motor units is also essential to strength endurance and smooth coordinated motion.  Related terminology may include; motor unit recruitment, preferential recruitment, rate coding, sequence, etc..

Example: It is hypothesized that the "shaking" noted during a novice exercisers attempt at an activity like the <a href="https://brentbrookbush.com/vimeo_videos/ball-crunch-and-progressions/" target="_blank">stability ball crunch</a> may be due to relatively poor intramuscular coordination. Rather than smooth, sequential firing of rectus abdominis motor units, groups of motor units turn on and off in an uncoordinated manner.

Pertaining to the same side

Example, the quadratus lumborum performs ipsilateral flexion; lateral flexion toward the same side as the muscle.

An isoform, or variant, is a member of a set of similar proteins, that originate from the same gene, or gene family.
<ul>
 	<li>Example, the variations in myosin heavy chain proteins (MHC I, MHC IIA, MHC IIB/X) that contribute to the characteristic differences between muscle fiber types.</li>
</ul>

“The Prime Assumption”
Everything crossing a joint will influence joint motion during every joint action.

A concept that has expanded over the past several decades to describe the integration of 4 body systems (muscle, joints, fascia and nerves), as well as, the coordinated function of various body segments (e.g. hip, knee and ankle) to produce motion. Kinetic referring to motion, and chain being an analogy for the interdependent link between systems.

Example, the posterior kinetic chain, refers to the integrated function of nerves, muscles, fascia and joints on the posterior side of the body.

The concept of the kinetic chain was originally adapted from the work of a mechanical engineer named Franz Reuleaux (Kinematics of Machinery (1875)) by Dr. Arthur Steindler in 1955 (Steindler A: Kinesiology of the Human Body. Springfield, IL, Charles C. Thomas Co.. 1955).

Latent Trigger Point - A myofascial trigger point that is not painful at rest, only painful when palpated, and may or may not exhibit a characteristic referral pain pattern when palpated.  Latent trigger points do result in an acute point of sensitivity, in a taut band of muscle, and may restrict range of motion (1).

Note: Based on the clinical experience, the Brookbush Institute suggests that latent trigger points (sometimes refereed to as Tender Points) are more common than active trigger points. Further, they are likely addressed more often than trigger points; being the intended target of many soft-tissue mobility techniques.
<ol>
 	<li>David G. Simons, Janet Travell, Lois S. Simons, Travell &amp; Simmons’ Myofascial Pain and Dysfunction, The Trigger Point Manual, Volume 1. Upper Half of Body: Second Edition,© 1999 Williams and Wilkens</li>
</ol>

An anatomical direction; further from the midline

Example, the anterior deltoid is lateral to the pectoralis major

Length/Tension Relationship - The amount of force generated by a muscle is dependent on sarcomere length.
<ul>
 	<li>The ability of sarcomere to maximally produce force occurs when sarcomere length results in optimal overlap between actin and myosin. Stretching a sarcomere decreases overlap between actin and myosin filaments and reduces force production (1-3). When length is less than optimal, actin from opposite ends overlap and interfere with cross-bridging, and myosin filament are compressed as they contact the the Z-disk also reducing force (4)</li>
</ul>
<ol>
 	<li>Gordon, A. M., Huxley, A. F., &amp; Julian, F. J. (1966). The variation in isometric tension with sarcomere length in vertebrate muscle fibres. The Journal of physiology, 184(1), 170-192.</li>
 	<li>Edman, K. A. P. (1966). The relation between sarcomere length and active tension in isolated semitendinosus fibres of the frog. The Journal of Physiology, 183(2), 407-417.</li>
 	<li>Lieber, R. L., Loren, G. J., &amp; Friden, J. (1994). In vivo measurement of human wrist extensor muscle sarcomere length changes. Journal of neurophysiology, 71(3), 874-881.</li>
 	<li>Lieber, R. L. (2002). Skeletal muscle structure, function, and plasticity. Lippincott Williams &amp; Wilkins.</li>
</ol>
&nbsp;

Levels of Evidence - Relative to evidence-based practice, levels of evidence are an attempt to describe the strength of the results measured in a clinical trial or research study.  Note: levels of evidence do not supersede the critical evaluation of an experienced professional, and should be viewed as guidelines - a meta-analysis may be poorly constructed (Level IA), and a comparative study (Level III) may employ new technologies and a strong methodology.


The Levels of Evidence used by the Brookbush Institute, as described by Shekelle et al.(1):
<ul>
 	<li class="p1">IA - Evidence from meta-analysis of randomized controlled trials</li>
 	<li class="p1">IB - Evidence from at least one randomized controlled trial</li>
 	<li class="p1">IIA - Evidence from at least one controlled study without randomization</li>
 	<li class="p1">IIB - Evidence from at least one other type of quasi-experimental study</li>
 	<li class="p1">III - Evidence from non-experimental descriptive studies, such as comparative studies, correlation studies, and case-control studies</li>
 	<li class="p1">IV - Evidence from expert committee reports or opinions or clinical experience of respected authorities, or both</li>
</ul>
<ol>
 	<li>Shekelle, P. G., Woolf, S. H., Eccles, M., &amp; Grimshaw, J. (1999). Developing clinical guidelines. Western Journal of Medicine, 170(6), 348.</li>
</ol>

Likelihood Ratios - Likilihood ratios are used for assessing the value of performing a diagnostic test. They use sensitivity and specificity to determine whether a test result usefully changes the practitioner's chance (probability) of reaching the correct assessment. Calculation of likelihood ratios is based on Baye's theorem.
<ul>
 	<li>Positive Likelihood Ratio (LR+) - The ratio of a positive test result in people with the pathology to a positive test result in people without the pathology.</li>
 	<li>Negative Likelihood Ratio (LR-) - The ratio of a negative test result in people with the pathology to a negative test result in people without the pathology.</li>
</ul>

Longitudinal Study - a research design that involves observing the same variables, several times over a period of time.
<ul>
 	<li>Example, the study by Hewett et al. (1) is a type of longitudinal study called a "cohort study." This study investigated whether excessive knee valgus during landing was a predictor of knee injury risk in adolescent females over the course of a season.</li>
</ul>
<ol>
 	<li><a href="https://brentbrookbush.com/articles/research-corner/knee/research-review-increased-valgus-during-landing-predicts-acl-injury-in-adolescent-female-athletes/" target="_blank" rel="noopener noreferrer">Hewett, T. E., Myer, G. D., Ford, K. R., Heidt, R. S., Colosimo, A. J., McLean, S. G., &amp; Succop, P. (2005). Biomechanical measures of neuromuscular control and valgus loading of the knee predict anterior cruciate ligament injury risk in female athletes A prospective study. The American journal of sports medicine, 33(4), 492-501</a></li>
</ol>

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Lower Extremity Dysfunction (LED): Predictive Model of Lower Extremity Movement Impairment

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