Introduction

How the Study Relates to Brookbush Institute Content

Study Summary

How this Study Contributes to the Body of Reseach

How the Findings Apply to Practice

How Does this Study Relate to Brookbush Institute Content

How this Study Contributes to the Body of Research

Regional Interdependence: Hip and Ankle

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Macrum et al. (2012). Effect of Limiting Ankle-Dorsiflexion Range of Motion on Lower Extremity Kinematics and Muscle-Activation Patterns During a Squat

Original Citation: Macrum, E., Bell, D. R., Boling, M., Lewek, M., &amp; Padua, D. (2012). Effect of limiting ankle-dorsiflexion range of motion on lower extremity kinematics and muscle-activation patterns during a squat. Journal of sport rehabilitation, 21(2), 144-150. - <a href="https://www.researchgate.net/profile/David_Bell8/publication/225058421_Effect_of_Limiting_Ankle-Dorsiflexion_Range_of_Motion_on_Lower_Extremity_Kinematics_and_Muscle-Activation_Patterns_During_a_Squat/links/0912f50b65e14558fc000000/Effect-of-Limiting-Ankle-Dorsiflexion-Range-of-Motion-on-Lower-Extremity-Kinematics-and-Muscle-Activation-Patterns-During-a-Squat.pdf" target="_blank" rel="noopener">ARTICLE</a>
Introduction: Patellofemoral pain syndrome (PFPS) is the most commonly diagnosed <a href="https://brookbushinstitute.com/article/knee" target="_blank" rel="noopener">knee</a> injury among runners (1-5). A growing body of research is demonstrating a correlation (and perhaps <a id="etiology" data-tip="1490" target="_blank" href="/glossary-term/etiology" class="glossary">causation</a>) between altered lower extremity alignment and <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> recruitment, and knee pain and injury (1-9). This 2012 study by U.S. researchers demonstrates that limited <a href="https://brookbushinstitute.com/article/ankle-joint-talocrural-subtalor-tibiofibular-joints" target="_blank" rel="noopener">ankle</a> dorsiflexion, is associated with increased dynamic <a href="https://brookbushinstitute.com/article/knee" target="_blank" rel="noopener">knee</a> valgus, decreased peak <a href="https://brookbushinstitute.com/article/knee" target="_blank" rel="noopener">knee</a> flexion and excursion, decreased <a href="https://brookbushinstitute.com/article/quadriceps-vastus-muscles" target="_blank" rel="noopener">quadriceps</a> activation, and increased <a href="https://brookbushinstitute.com/article/soleus" target="_blank" rel="noopener">soleus (SOL)</a> activation. Human movement professionals working with runners should consider assessing ankle dorsiflexion range of motion (ROM) and addressing any noted restrictions prior to the development of an injury.
<a href="https://www.datocms-assets.com/25800/1646158243-black-and-white-knee-va.png"><img src="https://www.datocms-assets.com/25800/1646158243-black-and-white-knee-va.png"></a>
Biomechanical reflectors on an individual demonstrating excessive knee valgus. (Image: Courtesy of http://www.xavierbarbier.com/online-course

<table>
 <tbody>
 <tr>
 <td width="40%">Study Design</td>
 <td>Cross-Sectional Correlation Study</td>
 </tr>
 <tr>
 <td>Level of Evidence</td>
 <td>III Evidence from non-experimental descriptive studies, such as comparative studies, correlation studies, and case-control studies</td>
 </tr>
 <tr>
 <td>Participant Characteristics</td>
 <td>Demographics
 <ul>
 <li>Age: 18-30 years</li>
 <li>Gender: 14 male, 15 female
 <ul>
 <li>1 male participant data was lost due to equipment malfunction</li>
 </ul>
 </li>
 <li>Characteristics:
 <ul>
 <li>Height: 173.5 +/- 12.1 cm</li>
 <li>Weight: 72.0 +/- 16.4 kg</li>
 </ul>
 </li>
 </ul>
 Inclusion Criteria:
 <ul>
 <li>Recreationally active - 30 minutes of exercise at least 3 days/week</li>
 </ul>
 Exclusion Criteria:
 <ul>
 <li>Lower extremity injury on either leg within the past three months that caused them to miss physical activity at least one day or required physician referral</li>
 <li>Lower extremity surgery on either leg within the past year</li>
 <li>Presence of current <a href="https://brookbushinstitute.com/article/knee" target="_blank" rel="noopener">knee</a> pain</li>
 </ul>
 </td>
 </tr>
 <tr>
 <td>Methodology</td>
 <td>
 <ul>
 <li>Participants tested in a single session lasting approximately 1 hour.</li>
 <li>The dominant leg was used for all data analysis.</li>
 <li>A warm-up was performed on a stationary bicycle for 5 minutes at a self-selected pace.</li>
 </ul>
 Intervention
 <ul>
 <li>Each participant performed 7 trials of a double-leg squat under 2 conditions:
 <ul>
 <li>A no-wedge (NW) condition with the feet flat on the floor</li>
 <li>A wedge (W) condition with the participant&apos;s feet on a 12&#xB0; forefoot elevated wedge</li>
 </ul>
 
 </li>
 <li>After all squat trials, participants performed 3 trials of maximal voluntary isometric contractions (MVICs) for:
 <ul>
 <li><a href="https://brookbushinstitute.com/article/quadriceps-vastus-muscles" target="_blank" rel="noopener">Vastus Lateralis (VL)</a></li>
 <li><a href="https://brookbushinstitute.com/article/quadriceps-vastus-muscles" target="_blank" rel="noopener">Vastus Medialis Oblique (VMO)</a></li>
 <li><a href="https://brookbushinstitute.com/article/soleus" target="_blank" rel="noopener">Soleus (SOL)</a></li>
 <li><a href="https://brookbushinstitute.com/article/gastrocnemius-plantaris" target="_blank" rel="noopener">Lateral Gastrocnemius (LG)</a></li>
 </ul>
 
 </li>
 </ul>
 </td>
 </tr>
 <tr>
 <td>Data Collection and Analysis</td>
 <td>Data Collection
 <ul>
 <li>Average surface electromyography (EMG) amplitude and peak kinematic values were calculated during the descending phase of each squat for <a href="https://brookbushinstitute.com/article/quadriceps-vastus-muscles" target="_blank" rel="noopener">VL</a>, <a href="https://brookbushinstitute.com/article/quadriceps-vastus-muscles" target="_blank" rel="noopener">VMO</a>, <a href="https://brookbushinstitute.com/article/soleus" target="_blank" rel="noopener">SOL</a>, <a href="https://brookbushinstitute.com/article/gastrocnemius-plantaris" target="_blank" rel="noopener">LG</a>.</li>
 <li>Kinematic-excursion values were calculated by subtracting the minimum values from peak values for each variable.</li>
 <li><a id="medial" data-tip="1568" target="_blank" href="/glossary-term/medial" class="glossary">Medial</a> <a href="https://brookbushinstitute.com/article/knee" target="_blank" rel="noopener">knee</a> displacement was calculated by subtracting the starting <a href="https://brookbushinstitute.com/article/knee" target="_blank" rel="noopener">knee</a>-center value before and after squat descent.</li>
 </ul>
 Data Analysis
 <ul>
 <li>Repeated measured analysis of variances (ANOVA) was analyzed for each <a id="dependent-variable" data-tip="1436" target="_blank" href="/glossary-term/dependent-variable" class="glossary">dependent variable</a> and the within-subject factor was the wedge condition (W, NW).</li>
 <li>Statistical significance was set at P &#x2264; 0.05.</li>
 </ul>
 </td>
 </tr>
 <tr>
 <td>Outcome Measures</td>
 <td>W vs. NW overhead body weight squat for the following measurements:
 <ul>
 <li>Peak joint angles
 <ul>
 <li><a href="https://brookbushinstitute.com/article/knee" target="_blank" rel="noopener">Knee</a>
 <ul>
 <li>Flexion/Extension</li>
 <li>Varus/Valgus</li>
 <li>Internal Rotation/External Rotation</li>
 </ul>
 </li>
 <li><a href="https://brookbushinstitute.com/article/ankle-joint-talocrural-subtalor-tibiofibular-joints" target="_blank" rel="noopener">Ankle</a>
 <ul>
 <li>Plantarflexion/Dorsiflexion</li>
 </ul>
 </li>
 <li><a href="https://brookbushinstitute.com/article/kinesiology-of-the-hip" target="_blank" rel="noopener">Hip</a>
 <ul>
 <li>Extension/Flexion</li>
 <li>Adduction/Abduction</li>
 <li>Internal Rotation/External Rotation</li>
 </ul>
 </li>
 </ul>
 </li>
 <li>Displacement values (in degrees)
 <ul>
 <li><a href="https://brookbushinstitute.com/article/knee" target="_blank" rel="noopener">Knee</a>
 <ul>
 <li>Sagittal Plane</li>
 <li>Frontal Plane</li>
 <li>Transverse Plane (rotation)</li>
 </ul>
 </li>
 <li><a href="https://brookbushinstitute.com/article/ankle-joint-talocrural-subtalor-tibiofibular-joints" target="_blank" rel="noopener">Ankle</a>
 <ul>
 <li>Sagittal Plane</li>
 </ul>
 </li>
 <li><a href="https://brookbushinstitute.com/article/kinesiology-of-the-hip" target="_blank" rel="noopener">Hip</a>
 <ul>
 <li>Sagittal Plane</li>
 <li>Frontal Plane</li>
 <li>Transverse Plane (rotation)</li>
 </ul>
 </li>
 <li>Body <a id="center-of-mass-gravity" data-tip="1186" target="_blank" href="/glossary-term/center-of-mass-gravity" class="glossary">Center of Mass</a> (<a id="center-of-mass-gravity" data-tip="1188" target="_blank" href="/glossary-term/center-of-mass-gravity" class="glossary">COM</a>)</li>
 </ul>
 </li>
 <li>Average EMG (%MVIC) during squat descent
 <ul>
 <li><a href="https://brookbushinstitute.com/article/quadriceps-vastus-muscles" target="_blank" rel="noopener">VL</a></li>
 <li><a href="https://brookbushinstitute.com/article/quadriceps-vastus-muscles" target="_blank" rel="noopener">VMO</a></li>
 <li><a href="https://brookbushinstitute.com/article/soleus" target="_blank" rel="noopener">SOL</a></li>
 <li><a href="https://brookbushinstitute.com/article/gastrocnemius-plantaris" target="_blank" rel="noopener">LG</a></li>
 </ul>
 </li>
 </ul>
 </td>
 </tr>
 <tr>
 <td>Results</td>
 <td>NW Condition
 <ul>
 <li>Increased peak <a href="https://brookbushinstitute.com/article/knee" target="_blank" rel="noopener">knee</a> flexion (96.7 +/- 17.3&#xB0; vs. 81.1 +/- 19.2&#xB0;, P &lt; 0.01)</li>
 <li>Increased <a href="https://brookbushinstitute.com/article/knee" target="_blank" rel="noopener">knee</a> sagittal plane displacement (100.2 +/- 16.8&#xB0; vs. 85.1 +/- 18.5&#xB0;, P &lt; 0.01)</li>
 <li>Increased <a href="https://brookbushinstitute.com/article/ankle-joint-talocrural-subtalor-tibiofibular-joints" target="_blank" rel="noopener">ankle</a> sagittal plane displacement (28.8 +/- 6.0&#xB0; vs. 21.3 +/- 5.9&#xB0;, P &lt; 0.01)</li>
 <li>Increased <a href="https://brookbushinstitute.com/article/quadriceps-vastus-muscles" target="_blank" rel="noopener">VL</a> activity (62.4 +/- 21.8% vs. 55.1 +/- 18.6%, P &lt; 0.01)</li>
 <li>Increased <a href="https://brookbushinstitute.com/article/quadriceps-vastus-muscles" target="_blank" rel="noopener">VMO</a> activity (66.2 +/- 26.1% vs. 61.2 +/- 21.2%, P = 0.03)</li>
 </ul>
 W Condition
 <ul>
 <li>Increased peak <a href="https://brookbushinstitute.com/article/knee" target="_blank" rel="noopener">knee</a> valgus (4.1 +/- 3.3&#xB0; vs. 3.4 +/- 3.2&#xB0;, P = 0.02)</li>
 <li>Increased peak <a href="https://brookbushinstitute.com/article/ankle-joint-talocrural-subtalor-tibiofibular-joints" target="_blank" rel="noopener">ankle</a> dorsiflexion (30.0 +/- 6.3&#xB0; vs. 28.0 +/- 6.4&#xB0;, P &lt; 0.01)</li>
 <li>Increased <a id="posterior" data-tip="1565" target="_blank" href="/glossary-term/posterior" class="glossary">posterior</a> displacement of the body <a id="center-of-mass-gravity" data-tip="1188" target="_blank" href="/glossary-term/center-of-mass-gravity" class="glossary">COM</a> (0.07 +/- 0.03 m vs. 0.05 +/- 0.03 m, P &lt; 0.01)</li>
 <li>Increased <a href="https://brookbushinstitute.com/article/soleus" target="_blank" rel="noopener">SOL</a> activity (23.4 +/- 2.4 vs. 21.8 +/- 2.6%, P = 0.03)</li>
 </ul>
 </td>
 </tr>
 <tr>
 <td>Our Conclusions</td>
 <td>The results of this study demonstrate that restrictions in <a href="https://brookbushinstitute.com/article/ankle-joint-talocrural-subtalor-tibiofibular-joints" target="_blank" rel="noopener">ankle</a> dorsiflexion can influence <a href="https://brookbushinstitute.com/article/knee" target="_blank" rel="noopener">knee</a> kinematics by increasing dynamic <a href="https://brookbushinstitute.com/article/knee" target="_blank" rel="noopener">knee</a> valgus, decreasing peak <a href="https://brookbushinstitute.com/article/knee" target="_blank" rel="noopener">knee</a> flexion and excursion, reducing muscle activity of the <a href="https://brookbushinstitute.com/article/quadriceps-vastus-muscles" target="_blank" rel="noopener">quadriceps</a>, and increasing <a href="https://brookbushinstitute.com/article/soleus" target="_blank" rel="noopener">SOL</a> activity. This study demonstrates that restricted motion at one segment can result in altered motion of proximal segments. The alterations noted in this study are similar to those noted in the predictive model of <a href="https://brookbushinstitute.com/article/lower-leg-dysfunction" target="_blank" rel="noopener">Lower Extremity Dysfunction (LED)</a>.</td>
 </tr>
 <tr>
 <td>Researchers&apos; Conclusions
 
 </td>
 <td>This study demonstrates that tightness in the gastroc-soleus complex leads to decreased sagittal plane motion at the <a href="https://brookbushinstitute.com/article/ankle-joint-talocrural-subtalor-tibiofibular-joints" target="_blank" rel="noopener">ankle</a> and increased frontal plane motion at the <a href="https://brookbushinstitute.com/article/knee" target="_blank" rel="noopener">knee</a>, as well as increased activity of the <a href="https://brookbushinstitute.com/article/soleus" target="_blank" rel="noopener">SOL</a> and decreased activity in the <a href="https://brookbushinstitute.com/article/quadriceps-vastus-muscles" target="_blank" rel="noopener">quadriceps</a>. Excessive frontal plane motion at the knee may predispose individuals to Patellofemoral Pain Syndrome (PFPS) and further LE malalignment and compensatory strategies, likely extending proximally to the hip.</td>
 </tr>
 </tbody>
</table>
<a href="https://www.datocms-assets.com/25800/1646158313-screencapture-vimeo-226076154-1502059394190-1.png"><img src="https://www.datocms-assets.com/25800/1646158313-screencapture-vimeo-226076154-1502059394190-1.png" width="520" height="414"></a>
<a id="posterior" data-tip="1565" target="_blank" href="/glossary-term/posterior" class="glossary">Posterior</a> talar <a id="glide" data-tip="1600" target="_blank" href="/glossary-term/glide" class="glossary">glides</a> are effective at improving ankle dorsiflexion range of motion. (Image: Courtesy of www.BrentBrookbush.com)

The relationships between Patellofemoral Pain Syndrome (PFPS) and <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</a> kinematics, highlight the interdependence of lower extremity (LE) joints and muscles (10-15). Previous research has shown a correlation between decreased <a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">hip</a> strength and increased dynamic <a href="https://brookbushinstitute.com/article/knee" target="_blank" rel="noopener">knee</a> valgus, demonstrating the influence of <a id="proximal" data-tip="1564" target="_blank" href="/glossary-term/proximal" class="glossary">proximal</a> joint dysfunction and <a id="distal" data-tip="1563" target="_blank" href="/glossary-term/distal" class="glossary">distal</a> joint motion (6-9). Unique to this study, the researchers investigated a <a id="distal" data-tip="1563" target="_blank" href="/glossary-term/distal" class="glossary">distal</a> limitation of <a href="https://brookbushinstitute.com/article/ankle-joint-talocrural-subtalor-tibiofibular-joints" target="_blank" rel="noopener">ankle</a> dorsiflexion and the effect on the <a id="proximal" data-tip="1564" target="_blank" href="/glossary-term/proximal" class="glossary">proximal</a> <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> joints. This study demonstrates that a correlation exists between <a href="https://brookbushinstitute.com/article/ankle-joint-talocrural-subtalor-tibiofibular-joints" target="_blank" rel="noopener">ankle</a> dorsiflexion, dynamic <a href="https://brookbushinstitute.com/article/knee" target="_blank" rel="noopener">knee</a> valgus, and activity of the <a href="https://brookbushinstitute.com/article/quadriceps-vastus-muscles" target="_blank" rel="noopener">quadriceps</a> and <a href="https://brookbushinstitute.com/article/soleus" target="_blank" rel="noopener">soleus (SOL)</a> muscles during a squat.

The findings of this study demonstrate a correlation between restricted <a href="https://brookbushinstitute.com/article/ankle-joint-talocrural-subtalor-tibiofibular-joints" target="_blank" rel="noopener">ankle</a> motion and altered <a href="https://brookbushinstitute.com/article/knee" target="_blank" rel="noopener">knee</a> motion, <a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">hip</a> motion, and <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> activity during a squat. This study demonstrates <a href="https://brookbushinstitute.com/glossary/regional-interdependence/" target="_blank" rel="noopener">regional interdependence</a> between <a href="https://brookbushinstitute.com/glossary/proximal/" target="_blank" rel="noopener">proximal</a> and <a href="https://brookbushinstitute.com/glossary/distal/" target="_blank" rel="noopener">distal</a> segments of the lower extremity. This implies that human movement professionals should <a id="assessment" data-tip="1486" target="_blank" href="/glossary-term/assessment" class="glossary">assess</a> and address 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</a> in patients/clients with <a href="https://brookbushinstitute.com/article/lower-leg-dysfunction" target="_blank" rel="noopener">Lower Extremity Dysfunction (LED)</a> regardless of the site of pain or injury. The correlation made in this study may further imply that addressing <a href="https://brookbushinstitute.com/article/ankle-joint-talocrural-subtalor-tibiofibular-joints" target="_blank" rel="noopener">ankle</a> dorsiflexion restriction may aid in preventing alterations in lower extremity mechanics and the development of patellofemoral pain syndrome (PFPS).
This study had many methodological strengths, including:
<ul>
 <li>This study filled a gap in the body of research by demonstrating the relationship between sagittal plane <a href="https://brookbushinstitute.com/article/ankle-joint-talocrural-subtalor-tibiofibular-joints" target="_blank" rel="noopener">ankle</a> motion restrictions and <a href="https://brookbushinstitute.com/article/knee" target="_blank" rel="noopener">knee</a> kinematics during a squat.</li>
 <li>The study included EMG data and kinematic analysis allowing for direct comparison of the various measurements in the same participant group. Prior to this study this information would be gathered from multiple studies and compared indirectly.</li>
 <li>The wedge (W) intervention was placed under both lower extremities during testing to the development of asymmetric compensation patterns that may have affected outcomes.</li>
</ul>
Weaknesses that should be noted prior to clinical <a id="integration" data-tip="1472" target="_blank" href="/glossary-term/integration" class="glossary">integration</a> of the findings include:
<ul>
 <li>Squat depth and cadence were not controlled which may have influenced EMG data.</li>
 <li>A larger number of participants may have increased the confidence interval; low effect sizes were observed for the EMG data.</li>
 <li>The data analysis markers were placed over the participant&apos;s shoes which may have altered kinematic data obtained at the ankle.</li>
 <li>Although the participants exhibited abnormal mechanics under the intervention condition, they were asymptomatic. Further research should investigate participants with Patellofemoral Pain Syndrome (PFPS) to determine if a correlation exists between dorsiflexion restriction and PFPS.</li>
</ul>

The Brookbush Institute (BI) has developed <a href="https://brookbushinstitute.com/article/introduction-to-postural-dysfunction-and-movement-impairment" target="_blank" rel="noopener">predictive </a><a id="model" data-tip="1471" target="_blank" href="/glossary-term/model" class="glossary">models</a> of <a id="posture" data-tip="1659" target="_blank" href="/glossary-term/posture" class="glossary">postural</a> dysfunction based on evidence of common tissue changes (<a href="https://brookbushinstitute.com/glossary/muscle-cell/" target="_blank" rel="noopener">muscle</a>, joint, fascia, and <a href="https://brookbushinstitute.com/glossary/nerve-cell/" target="_blank" rel="noopener">nerve</a>) to aid human movement professionals in selecting <a href="https://brookbushinstitute.com/glossary/optimal/" target="_blank" rel="noopener">optimal</a> <a href="https://brookbushinstitute.com/glossary/assessment/" target="_blank" rel="noopener">assessments</a>, manual interventions, and exercise. This study demonstrates that limitations in ankle dorsiflexion during a squat resulted in increased dynamic <a href="https://brookbushinstitute.com/article/knee" target="_blank" rel="noopener">knee</a> valgus, decreased peak <a href="https://brookbushinstitute.com/article/knee" target="_blank" rel="noopener">knee</a> flexion and excursion, decreased <a href="https://brookbushinstitute.com/article/quadriceps-vastus-muscles" target="_blank" rel="noopener">quadriceps</a> activation, and increased <a href="https://brookbushinstitute.com/article/soleus" target="_blank" rel="noopener">soleus (SOL)</a> activation. These changes are similar to the changes in biomechanics described 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/lower-leg-dysfunction" target="_blank" rel="noopener">Lower Extremity Dysfunction (LED)</a>.

Gastrocnemius and Soleus (Calf) Static Self-Administered Release
<iframe src="https://player.vimeo.com/video/76690427" frameborder="0"></iframe>
Self- Administered Ankle Mobilization
<iframe src="https://player.vimeo.com/video/93046320" frameborder="0"></iframe>
Calf Stretch
<iframe src="https://player.vimeo.com/video/82873997" frameborder="0"></iframe>
Tibialis <a id="anterior" data-tip="1566" target="_blank" href="/glossary-term/anterior" class="glossary">Anterior</a> Isolated Activation
<iframe src="https://player.vimeo.com/video/82875971" frameborder="0"></iframe>
Tibialis <a id="posterior" data-tip="1565" target="_blank" href="/glossary-term/posterior" class="glossary">Posterior</a> Isolated Activation Progression
<iframe src="https://player.vimeo.com/video/117064975" frameborder="0"></iframe>
Deadlift with <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> Pull
<iframe src="https://player.vimeo.com/video/117063783" frameborder="0"></iframe>

Bibliography

Franettovich et al. (2014). Neuromotor Control of Gluteal Muscles in Runners with Achilles Tendinopathy

Original Citation: Franettovich, M. S., Honeywill, C., Wyndow, N., Crossley, K. M., &amp; Creaby, M. W. (2014). Neuromotor control of gluteal muscles in runners with achilles tendinopathy. Medicine and science in sports and exercise, 46(3), 594-599. - <a href="http://europepmc.org/abstract/MED/24121244" target="_blank" rel="noopener">ABSTRACT</a>
Achilles tendinopathy (AT) is a condition resulting in foot and <a href="https://brookbushinstitute.com/article/ankle-joint-talocrural-subtalor-tibiofibular-joints" target="_blank" rel="noopener">ankle</a> pain, accounting for 8-15% of all injuries in recreational runners (1-3). While previous studies have demonstrated a relationship between individuals with AT and a significant reduction in amplitude of <a href="https://brookbushinstitute.com/article/gluteus-medius" target="_blank" rel="noopener">gluteus medius (GMED)</a> activity after heel strike, <a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">hip</a> <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> activation timing patterns have not been studied (4). This 2014 study by U.S. researchers demonstrated a correlation between delayed, shorter duration activity of the <a href="https://brookbushinstitute.com/article/gluteus-maximus" target="_blank" rel="noopener">gluteus maximus (GMAX)</a> and <a href="https://brookbushinstitute.com/article/gluteus-medius" target="_blank" rel="noopener">GMED</a> in runners with AT. Human movement professionals should consider assessing <a href="https://brookbushinstitute.com/article/gluteus-maximus" target="_blank" rel="noopener">GMAX</a> and <a href="https://brookbushinstitute.com/article/gluteus-medius" target="_blank" rel="noopener">GMED</a> strength/re-activity and address any noted weaknesses in those exhibiting signs of AT.
<a href="https://www.datocms-assets.com/25800/1646158921-achilles-tendinopathy.jpeg"><img src="https://www.datocms-assets.com/25800/1646158921-achilles-tendinopathy.jpeg" width="409" height="307"></a> Achilles tendinopathy. (Image: Courtesy http://www.getactivephysio.com.au/conditions-treated/achilles-tendinopathy/)

<table>
 <tbody>
 <tr>
 <td width="40%">Study Design</td>
 <td>Cross-Sectional Correlation Study</td>
 </tr>
 <tr>
 <td>Level of Evidence</td>
 <td>IIB Evidence from at least one quasi-experimental study</td>
 </tr>
 <tr>
 <td>Participant Characteristics</td>
 <td>Demographics
 <ul>
 <li>Age:
 <ul>
 <li>Achilles tendinopathy (AT) study group: 43 +/- 8 years</li>
 <li>Uninjured control group: 37 +/- 8 years</li>
 </ul>
 
 </li>
 <li>Gender: male</li>
 <li>Number of participants: 33
 <ul>
 <li>14 in the study group</li>
 <li>19 in the control group</li>
 </ul>
 
 </li>
 <li>Runners: with AT and healthy controls</li>
 </ul>
 Inclusion Criteria:
 <ul>
 <li>Both groups:
 <ul>
 <li>Male, older than 18 years and currently running &#x2265; 20 kilometers (km)/week</li>
 </ul>
 
 </li>
 <li>AT study group:
 <ul>
 <li>No other lower limb injury at the time of testing or in the past 12 months aside from symptoms of midportion AT, which include: Achilles tendon pain with running, hopping and palpation; morning stiffness; and symptoms affecting exercise activity</li>
 <li>Confirmation via diagnostic ultrasound</li>
 </ul>
 
 </li>
 <li>Uninjured control group:
 <ul>
 <li>Free from injury at the time of testing and no lower limb injury that stopped the participant from running for more than 1 week for 12 months prior to testing</li>
 <li>No observable features of tendinopathy on diagnostic ultrasound</li>
 </ul>
 
 </li>
 </ul>
 Exclusion Criteria:
 <ul>
 <li>History of lower limb surgery, systemic inflammatory disorders or Achilles tendon trauma or rupture.</li>
 </ul>
 </td>
 </tr>
 <tr>
 <td>Methodology</td>
 <td>
 <ul>
 <li>Diagnostic ultrasound was used to confirm each participant&apos;s eligibility for their respective groups
 <ul>
 <li>Features of AT for inclusion in the study group: tendon thickening and/or focal lesion</li>
 </ul>
 
 </li>
 <li>Participant characteristics were collected from all participants, including: age, height, weight and weekly running volumes</li>
 <li>Participants in the AT group completed questionnaires regarding the affected side, symptom duration and the Victorian Institute of Sport Assessment-Achilles (VISA-A) questionnaire
 <ul>
 <li>VISA-A is a validated and <a id="reliability" data-tip="1795" target="_blank" href="/glossary-term/reliability" class="glossary">reliable</a> index of clinical severity of AT (5)
 <ul>
 <li>Consists of 8 questions that measure the domains of pain, function in daily living and sporting activity</li>
 <li>Scores range from 1 to 100, with 100 representing an asymptomatic score</li>
 </ul>
 
 </li>
 </ul>
 </li>
 <li>Participants were required to run at 4 meters (m)/second (s) (+/- 10%) on a 25 m walkway wearing Nike Straprunner IV running sandals while Electromyographic (EMG) activity from the <a href="https://brookbushinstitute.com/article/gluteus-maximus" target="_blank" rel="noopener">Gluteus Maximus (GMAX)</a> and <a href="https://brookbushinstitute.com/article/gluteus-medius" target="_blank" rel="noopener">Gluteus Medius (GMED)</a> was collected.
 <ul>
 <li>Given approximately 3 minutes to accommodate to footwear, equipment and required speed</li>
 <li>A minimum of 6 trials were obtained for analysis</li>
 <li>The symptomatic or most symptomatic leg was used for testing for the AT study group, and the dominant leg was used for the control group</li>
 <li>Timing gates were used to confirm the running velocity</li>
 <li>Force plate data was collected to identify heel strike and toe-off events during gait</li>
 </ul>
 
 </li>
 </ul>
 </td>
 </tr>
 <tr>
 <td>Data Collection and Analysis</td>
 <td>Data Collection
 <ul>
 <li>3 temporal variables were manually identified by visual inspection of EMG data:
 <ul>
 <li>Onset of <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> activity (onset)</li>
 <li>Offset of <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> activity (offset)</li>
 <li>Duration of <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> activity (duration)
 <ul>
 <li>The amount of time in milliseconds (ms) that the <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> was active, calculated as the difference between the onset and offset times</li>
 </ul>
 
 </li>
 </ul>
 </li>
 <li>Onset and offset activity were then visually confirmed as the time point relative to heel strike when the burst of <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> activity started and finished in ms</li>
 <li>Intraclass Correlation Coefficients (ICC) were calculated to determine the <a id="reliability" data-tip="1515" target="_blank" href="/glossary-term/reliability" class="glossary">reliability</a> of the method of EMG onset and offset detection</li>
 </ul>
 Data Analysis
 <ul>
 <li>All data were analyzed using Statistical Packages for Social Sciences (SPSS) for Windows</li>
 <li>Skewness and kurtosis values were determined for distribution of the data</li>
 <li>A multivariate ANCOVA was performed for each <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> with between-subject factor of group (Achilles tendinopathy, control) and variables for onset, offset and duration
 <ul>
 <li>Age, weight and height were covariates</li>
 <li>Alpha level was set at 0.05 for all analyses</li>
 </ul>
 
 </li>
 <li>Tests of simple effects were performed to obtain the point estimates of statistically significant main effects
 <ul>
 <li>95% confidence interval was set for differences between groups</li>
 </ul>
 
 </li>
 <li>Standardized mean differences (SMD = mean difference/ standard deviation) were calculated to provide an estimate of the effect
 <ul>
 <li>Classified as small (0.2-0.6), moderate (0.6-1.2) or large (&gt;1.2)</li>
 </ul>
 
 </li>
 </ul>
 </td>
 </tr>
 <tr>
 <td>Outcome Measures</td>
 <td>
 <ul>
 <li>EMG activity of the <a href="https://brookbushinstitute.com/article/gluteus-maximus" target="_blank" rel="noopener">GMAX</a></li>
 <li>EMG activity of the <a href="https://brookbushinstitute.com/article/gluteus-medius" target="_blank" rel="noopener">GMED</a></li>
 <li>Heel strike during gait</li>
 <li>Toe-off during gait</li>
 <li>VISA-A score for AT study group</li>
 </ul>
 </td>
 </tr>
 <tr>
 <td>Results</td>
 <td>
 <ul>
 <li>No significant differences were found in height, weight or distance run each week between the two groups (P &gt; 0.05)</li>
 <li>The AT study group was significantly older than the control group
 <ul>
 <li>42.6 years AT study group</li>
 <li>36.6 years control group</li>
 <li>P = 0.04</li>
 </ul>
 
 </li>
 <li>VISA-A for the AT study group was a mean of 70 +/- 10</li>
 <li>Multivariate ANCOVA identified between-group differences for <a href="https://brookbushinstitute.com/article/gluteus-medius" target="_blank" rel="noopener">GMED</a> (P &lt; 0.001) and <a href="https://brookbushinstitute.com/article/gluteus-maximus" target="_blank" rel="noopener">GMAX</a> (P = 0.004)</li>
 <li><a href="https://brookbushinstitute.com/article/gluteus-medius" target="_blank" rel="noopener">GMED</a>:
 <ul>
 <li>Delay in the onset of activity by 0.16 s in the AT study group compared to controls (95% CI = 0.09-0.24 s, P &lt; 0.001, SMD = 2.1)</li>
 <li>Shorter duration of activation by 0.18 s in the AT study group compared to controls (95% CI = 0.10-0.25 s, P &lt; 0.001, SMD = 2.3)</li>
 <li>Offset was not significantly different between groups (P = 0.063)</li>
 </ul>
 
 </li>
 <li><a href="https://brookbushinstitute.com/article/gluteus-maximus" target="_blank" rel="noopener">GMAX</a>:
 <ul>
 <li>Delay in the onset of activity by 0.09 s in the AT study group compared to controls (95% CI = 0.03-0.16 s, P = 0.008, SMD = 1.4)</li>
 <li>Shorter duration of activation by 0.12 s in the AT study group compared to controls (95% CI = 0.05-0.19 s, P = 0.002, SMD = 1.8)</li>
 <li>Offset demonstrated earlier <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> activity by 0.03 s in the AT study group compared to controls (95% CI = 0.01-0.04 s, P = 0.001, SMD = 1.5)</li>
 </ul>
 
 </li>
 </ul>
 </td>
 </tr>
 <tr>
 <td>Our Conclusions</td>
 <td>The results of this study demonstrate a relationship between pathology at the <a href="https://brookbushinstitute.com/article/ankle-joint-talocrural-subtalor-tibiofibular-joints" target="_blank" rel="noopener">ankle</a> and altered neuromotor control of <a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">hip</a> musculature. This study supports the interdependence between the segments of the lower extremity, and the importance of the use of a dynamic postural assessment, such as the <a href="https://brookbushinstitute.com/article/introduction-overhead-squat-assessment" target="_blank" rel="noopener">overhead squat assessment</a> to determine the full extent of asymmetries and compensation patterns in individuals with <a href="https://brookbushinstitute.com/article/lower-leg-dysfunction" target="_blank" rel="noopener">Lower Extremity Dysfunction (LED)</a>.</td>
 </tr>
 <tr>
 <td>Researchers&apos; Conclusions
 
 </td>
 <td>This study demonstrates significant differences in the timing of the <a href="https://brookbushinstitute.com/article/gluteus-medius" target="_blank" rel="noopener">GMED</a> and <a href="https://brookbushinstitute.com/article/gluteus-maximus" target="_blank" rel="noopener">GMAX</a> muscles in runners with Achilles tendinopathy compared to uninjured healthy runners. While these results do not establish a causation relationship, they imply the importance of considering proximal factors, such as neuromotor control in the <a href="https://brookbushinstitute.com/article/gluteus-medius" target="_blank" rel="noopener">GMED</a> and <a href="https://brookbushinstitute.com/article/gluteus-maximus" target="_blank" rel="noopener">GMAX</a> muscles, when assessing and treating individuals with Achilles tendinopathy.</td>
 </tr>
 </tbody>
</table>
<a href="https://www.datocms-assets.com/25800/1646159072-hop-down-to-single-leg-touchdown-to-balance.png"><img src="https://www.datocms-assets.com/25800/1646159072-hop-down-to-single-leg-touchdown-to-balance.png" width="534" height="528"></a>
Hop Down to Single Leg Touchdown (<a id="exercise-progression" data-tip="1184" target="_blank" href="/glossary-term/exercise-progression" class="glossary">Progression</a> for Tibialis <a id="posterior" data-tip="1565" target="_blank" href="/glossary-term/posterior" class="glossary">Posterior</a> and Glute Complex Reactive Activation)

The relationships between <a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">hip</a> and <a href="https://brookbushinstitute.com/article/ankle-joint-talocrural-subtalor-tibiofibular-joints" target="_blank" rel="noopener">ankle</a> kinematics, gluteal <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> activation, and Achilles tendinopathy (AT) highlight the interdependence of lower extremity joints and muscles (6-11). Previous research on AT has noted minimal differences in calf <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> activation (4, 12), but a significant reduction in <a href="https://brookbushinstitute.com/article/gluteus-medius" target="_blank" rel="noopener">GMED</a> amplitude (4). Unique to this study, the researchers investigated the timing of <a href="https://brookbushinstitute.com/article/gluteus-maximus" target="_blank" rel="noopener">GMAX</a> and <a href="https://brookbushinstitute.com/article/gluteus-medius" target="_blank" rel="noopener">GMED</a> recruitment, noting a delay and shorter duration of activation during running. This study implies that altered neuromuscular control of <a href="https://brookbushinstitute.com/article/gluteus-maximus" target="_blank" rel="noopener">GMAX</a> and <a href="https://brookbushinstitute.com/article/gluteus-medius" target="_blank" rel="noopener">GMED</a> is more than a strength issue, additionally involving the timing and duration of recruitment.

The findings of this study correlate a delay and reduction in the duration of <a href="https://brookbushinstitute.com/article/gluteus-maximus" target="_blank" rel="noopener">GMAX</a> and <a href="https://brookbushinstitute.com/article/gluteus-medius" target="_blank" rel="noopener">GMED</a> activation with AT. This implies <a href="https://brookbushinstitute.com/glossary/regional-interdependence/" target="_blank" rel="noopener">regional interdependence</a> of the muscles and joints of the lower extremity; specifically, human movement professionals should consider an <a id="assessment" data-tip="1478" target="_blank" href="/glossary-term/assessment" class="glossary">assessment</a> of the <a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">hip</a> as well as the <a href="https://brookbushinstitute.com/article/ankle-joint-talocrural-subtalor-tibiofibular-joints" target="_blank" rel="noopener">ankle</a> in those exhibiting signs of ankle dysfunction. Further, human movement professionals should have a repertoire of techniques for addressing both <a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">hip</a> and <a href="https://brookbushinstitute.com/article/ankle-joint-talocrural-subtalor-tibiofibular-joints" target="_blank" rel="noopener">ankle</a> impairments, and consider the implementation of techniques targeting <a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">hip</a> structures for patients with ankle issues.
This study had many methodological strengths, including:
<ul>
 <li>This study filled a gap in the body of research by demonstrating the relationship between AT and the timing of gluteal <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> activation during running. This relationship had been theorized but not yet supported by research.</li>
 <li>Diagnostic ultrasound was used to confirm eligibility for group allocation for all participants, enhancing internal <a id="validity" data-tip="1511" target="_blank" href="/glossary-term/validity" class="glossary">validity</a>.</li>
 <li>The researchers used the VISA-A questionnaire, a validated and <a id="reliability" data-tip="1795" target="_blank" href="/glossary-term/reliability" class="glossary">reliable</a> index of clinical severity of AT, enhancing the <a id="reliability" data-tip="1515" target="_blank" href="/glossary-term/reliability" class="glossary">reliability</a> of outcome measures.</li>
 <li>The study and control groups in this study included participants who participated in weekly running activities in order to minimize extraneous variables.</li>
 <li>The researchers performed post hoc <a id="power" data-tip="1399" target="_blank" href="/glossary-term/power" class="glossary">power</a> calculations and demonstrated sufficient <a id="power" data-tip="1399" target="_blank" href="/glossary-term/power" class="glossary">power</a> in the number of participants in the study.</li>
</ul>
Weaknesses that should be noted prior to clinical <a id="integration" data-tip="1472" target="_blank" href="/glossary-term/integration" class="glossary">integration</a> of the findings include:
<ul>
 <li>The authors utilized surface EMG to collect <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> timing data, which is susceptible to cross-talk. Future research may consider confirmation of findings with fine wire EMG.</li>
 <li>This study examined the activation of the <a href="https://brookbushinstitute.com/article/gluteus-maximus" target="_blank" rel="noopener">gluteus maximus (GMAX)</a> and <a href="https://brookbushinstitute.com/article/gluteus-medius" target="_blank" rel="noopener">gluteus medius (GMED)</a> muscles. Future research may also consider the activity of other <a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">hip</a> muscles, such as <a href="https://brookbushinstitute.com/article/tensor-fascia-latae-tfl" target="_blank" rel="noopener">tensor fascia lata</a>, <a href="https://brookbushinstitute.com/article/gluteus-minimus" target="_blank" rel="noopener">gluteus minimus</a>, <a href="https://brookbushinstitute.com/article/semitendinosus-and-semimembranosus" target="_blank" rel="noopener">semitendinosus and semimembranosus</a>, <a href="https://brookbushinstitute.com/article/biceps-femoris" target="_blank" rel="noopener">biceps femoris</a>, and the <a href="https://brookbushinstitute.com/article/deep-rotators-of-the-hip" target="_blank" rel="noopener">deep external rotators</a>.</li>
</ul>

The Brookbush Institute (BI) has developed <a href="https://brookbushinstitute.com/article/introduction-to-postural-dysfunction-and-movement-impairment" target="_blank" rel="noopener">predictive </a><a id="model" data-tip="1471" target="_blank" href="/glossary-term/model" class="glossary">models</a> of <a id="posture" data-tip="1659" target="_blank" href="/glossary-term/posture" class="glossary">postural</a> dysfunction based on evidence of common tissue changes (<a href="https://brookbushinstitute.com/glossary/muscle-cell/" target="_blank" rel="noopener">muscle</a>, joint, fascia, and <a href="https://brookbushinstitute.com/glossary/nerve-cell/" target="_blank" rel="noopener">nerve</a>) to aid human movement professionals in selecting <a href="https://brookbushinstitute.com/glossary/optimal/" target="_blank" rel="noopener">optimal</a> <a href="https://brookbushinstitute.com/glossary/assessment/" target="_blank" rel="noopener">assessments</a>, manual interventions, and exercise. This study demonstrates that delayed activation and shorter duration of activation of the <a href="https://brookbushinstitute.com/article/gluteus-maximus" target="_blank" rel="noopener">gluteus maximus (GMAX)</a> and <a href="https://brookbushinstitute.com/article/gluteus-medius" target="_blank" rel="noopener">gluteus medius (GMED)</a> is associated with runners with Achilles tendinopathy; muscular maladaptations similar to those described in the <a href="https://brookbushinstitute.com/article/lower-leg-dysfunction" target="_blank" rel="noopener">Lower Extremity Dysfunction (LED)</a>. Further, this study demonstrates the importance of a dynamic movement <a href="https://brookbushinstitute.com/glossary/assessment/" target="_blank" rel="noopener">assessment</a>, such as the <a href="https://brookbushinstitute.com/article/introduction-overhead-squat-assessment" target="_blank" rel="noopener">overhead squat assessment</a> to determine <a href="https://brookbushinstitute.com/glossary/compensation-pattern/" target="_blank" rel="noopener">compensation patterns</a> that include multiple joints. This study also alludes to changes in timing and reactivity of the affected musculature, supporting the addition of &#x201C;Reactive Activation&#x201D; to the Brookbush Institute <a href="https://brookbushinstitute.com/glossary/integration/" target="_blank" rel="noopener">Integrated</a> Warm-Up and Rehabilitation Templates.

Side Stepping - <a href="https://brookbushinstitute.com/article/gluteus-medius" target="_blank" rel="noopener">Gluteus Medius</a> Reactive Activation
<iframe src="https://player.vimeo.com/video/76716671" frameborder="0" allowfullscreen="allowfullscreen"></iframe>
Side Stepping <a id="exercise-progression" data-tip="1182" target="_blank" href="/glossary-term/exercise-progression" class="glossary">Progressions</a> - <a href="https://brookbushinstitute.com/article/gluteus-medius" target="_blank" rel="noopener">Gluteus Medius</a> Reactive Activation
<iframe src="https://player.vimeo.com/video/76716828" frameborder="0" allowfullscreen="allowfullscreen"></iframe>
Side Stepping, Another <a id="exercise-progression" data-tip="1184" target="_blank" href="/glossary-term/exercise-progression" class="glossary">Progression</a> - <a href="https://brookbushinstitute.com/article/gluteus-medius" target="_blank" rel="noopener">Gluteus Medius</a> Reactive Activation
<iframe src="https://player.vimeo.com/video/109410320" frameborder="0" allowfullscreen="allowfullscreen"></iframe>
<a href="https://brookbushinstitute.com/article/gluteus-medius" target="_blank" rel="noopener">Gluteus Medius</a> Reactive Integration: Side Hop Progression
<iframe src="https://player.vimeo.com/video/76692013" frameborder="0" allowfullscreen="allowfullscreen"></iframe>
<a href="https://brookbushinstitute.com/article/gluteus-maximus" target="_blank" rel="noopener">Gluteus Maximus</a> Reactive Activation
<iframe src="https://player.vimeo.com/video/76690982" frameborder="0" allowfullscreen="allowfullscreen"></iframe>
<a href="https://brookbushinstitute.com/article/gluteus-maximus" target="_blank" rel="noopener">Gluteus Maximus</a> Reactive Activation Progressions
<iframe src="https://player.vimeo.com/video/76690880" frameborder="0" allowfullscreen="allowfullscreen"></iframe>
Hop Down to Single Leg Touchdown to Balance
<iframe src="https://player.vimeo.com/video/135007963" frameborder="0" allowfullscreen="allowfullscreen"></iframe>

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 <li>Munteanu, S. E., &amp; Barton, C. J. (2011). Lower limb biomechanics during running in individuals with achilles tendinopathy: a systematic review. Journal of foot and ankle research, 4(1), 15.</li>
 <li>Azevedo, L. B., Lambert, M. I., Vaughan, C. L., O&rsquo;Connor, C. M., &amp; Schwellnus, M. P. (2009). Biomechanical variables associated with Achilles tendinopathy in runners. British journal of sports medicine, 43(4), 288-292.</li>
 <li>Robinson, J. M., Cook, J. L., Purdam, C., Visentini, P. J., Ross, J., Maffulli, N., &hellip; &amp; Khan, K. M. (2001). The VISA-A questionnaire: a valid and reliable index of the clinical severity of Achilles tendinopathy. British journal of sports medicine, 35(5), 335-341.</li>
 <li><a href="https://brookbushinstitute.com/article/relationship-between-ankle-and-hip-motion" target="_blank" rel="noopener">Souza, T. R., Pinto, R. Z., Trede, R. G., Kirkwood, R. N., &amp; Fonseca, S. T. (2010). Temporal couplings between rearfoot&ndash;shank complex and hip joint during walking. Clinical biomechanics, 25(7), 745-748.</a></li>
 <li>Barton, C. J., Levinger, P., Crossley, K. M., Webster, K. E., &amp; Menz, H. B. (2012). The relationship between rearfoot, tibial and hip kinematics in individuals with patellofemoral pain syndrome. Clinical biomechanics, 27(7), 702-705.</li>
 <li>Willson, J. D., Kernozek, T. W., Arndt, R. L., Reznichek, D. A., &amp; Straker, J. S. (2011). Gluteal muscle activation during running in females with and without patellofemoral pain syndrome. Clinical biomechanics, 26(7), 735-740.</li>
 <li>Donoghue, O. A., Harrison, A. J., Laxton, P., &amp; Jones, R. K. (2008). Lower limb kinematics of subjects with chronic achilles tendon injury during running. Research in Sports Medicine, 16(1), 23-38.</li>
 <li>Mccrory, J. L., Martin, D. F., Lowery, R. B., Cannon, D. W., Curl, W. W., Read, J. H., &hellip; &amp; Messier, S. P. (1999). Etiologic factors associated with Achilles tendinitis in runners. Medicine and science in sports and exercise, 31(10), 1374-1381.</li>
 <li>Ryan, M., Grau, S., Krauss, I., Maiwald, C., Taunton, J., &amp; Horstmann, T. (2009). Kinematic analysis of runners with achilles mid-portion tendinopathy. Foot &amp; ankle international, 30(12), 1190-1195.</li>
 <li>Wyndow, N., Cowan, S. M., Wrigley, T. V., &amp; Crossley, K. M. (2013). Triceps surae activation is altered in male runners with Achilles tendinopathy. Journal of Electromyography and Kinesiology, 23(1), 166-172.</li>
</ol>

Souza et al. (2010). Temporal Couplings Between Rearfoot-Shank Complex and Hip Joint During Walking

Original Citation: Souza, T. R., Pinto, R. Z., Trede, R. G., Kirkwood, R. N., &amp; Fonseca, S. T. (2010). Temporal couplings between rearfoot&#x2013;shank complex and hip joint during walking. Clinical biomechanics, 25(7), 745-748. - <a href="https://www.clinbiomech.com/article/S0268-0033(10)00121-X/abstract" target="_blank" rel="noopener">ARTICLE</a>
<h3>Introduction:</h3>
A common assumption is that rearfoot ankle pronation occurs with hip internal rotation and rearfoot ankle supination with hip external rotation during walking. While previous studies have not shown a link between hip and ankle movements (1), deviations from this coupling pattern are thought to contribute to increased risk of lower extremity injury (2-5). This 2010 study by Brazilian and Australian researchers demonstrates a temporal coupling between rearfoot pronation and <a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">hip</a> IR and rearfoot supination with <a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">hip</a> ER during stance. Understanding this coupled motion may aid human movement professionals in choosing <a id="assessment" data-tip="1480" target="_blank" href="/glossary-term/assessment" class="glossary">assessments</a> to identify dysfunctional motion, and choose interventions to optimize motion.
<a href="https://www.datocms-assets.com/25800/1646159341-stjclosedkinematics.jpeg"><img src="https://www.datocms-assets.com/25800/1646159341-stjclosedkinematics.jpeg"></a>
Mechanics of the shank/rearfoot. (Image: Courtesy http://www.pt.ntu.edu.tw/hmchai/Kinesiology/KINlower/Foot.files/FootKinematics.htm)

<table>
 <tbody>
 <tr>
 <td width="40%">Study Design</td>
 <td>Cross-Correlational Study</td>
 </tr>
 <tr>
 <td>Level of Evidence</td>
 <td>IIB Evidence from at least one other type of quasi-experimental study</td>
 </tr>
 <tr>
 <td>Participant Characteristics</td>
 <td>Demographics
 <ul>
 <li>Age: mean 22.89 +/- 1.46</li>
 <li>Gender: 11 female and 7 male</li>
 <li>Number of participants: 18</li>
 <li>Young, healthy individuals</li>
 </ul>
 Inclusion Criteria:
 <ul>
 <li>No history of surgery or injury to the lower extremity (LE) or lumbopelvic-hip complex</li>
 </ul>
 Exclusion Criteria:
 <ul>
 <li>BMI greater than 25 (mean BMI was 21.56 +/- 0.36)</li>
 </ul>
 </td>
 </tr>
 <tr>
 <td>Methodology</td>
 <td>
 <ul>
 <li>Three-dimensional kinematics of the right LE and pelvis were analyzed during the stance phase of gait
 <ul>
 <li>Participants walked on a 10-meter walkway at their natural speed using trekking sandals with flat bases</li>
 <li>6 trials were completed</li>
 <li>Anatomical markers and a 6-camera motion analysis system were used to determine the motions of the pelvis, thigh shank and rearfoot</li>
 </ul>
 
 </li>
 </ul>
 </td>
 </tr>
 <tr>
 <td>Data Collection and Analysis</td>
 <td>Kinematic Variables
 <ul>
 <li>Visual 3D software was used to measure:
 <ul>
 <li>Transverse plane shank movement = shank internal/external rotation (IR/ER) at the <a href="https://brookbushinstitute.com/article/ankle-joint-talocrural-subtalor-tibiofibular-joints" target="_blank" rel="noopener">ankle</a> (seen as connected with rearfoot abduction/adduction) with respect to rearfoot frontal plane movement</li>
 <li>Frontal plane rearfoot movement = rearfoot inversion/eversion (INV/EV) with respect to shank transverse plane movement</li>
 <li>Transverse plane hip movement = <a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">hip</a> IR/ER as the thigh with respect to the pelvis</li>
 </ul>
 
 </li>
 <li>Shank IR (rearfoot abduction) and rearfoot EV are components of foot pronation.</li>
 <li>Shank ER (rearfoot adduction) and rearfoot INV are components of foot supination.</li>
 <li>Timing of peak motion = period between initial contact of stance and peak angular displacement (presented as percent of total stance phase for each kinematic variable)</li>
 <li>Mean values of the 6 trials for each participant were used for analysis</li>
 </ul>
 Data Analysis
 <ul>
 <li>Cross-correlation coefficients (CC) were calculated to <a id="assessment" data-tip="1486" target="_blank" href="/glossary-term/assessment" class="glossary">assess</a> the connection in timing between <a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">hip</a> and rearfoot/shank complex motions (allows for consideration of delays in timing)</li>
 <li>Pearson Correlation (PC) was calculated to <a id="assessment" data-tip="1486" target="_blank" href="/glossary-term/assessment" class="glossary">assess</a> whether individuals who show longer periods of shank IR and rearfoot EV also show longer periods of <a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">hip</a> IR
 <ul>
 <li>Level of significance was set at 0.05</li>
 </ul>
 
 </li>
 </ul>
 </td>
 </tr>
 <tr>
 <td>Outcome Measures</td>
 <td>
 <ul>
 <li>Transverse plane shank movement</li>
 <li>Frontal plane rearfoot movement</li>
 <li>Transverse plane <a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">hip</a> movement</li>
 <li>Timing of peak motion</li>
 </ul>
 </td>
 </tr>
 <tr>
 <td>Results</td>
 <td>
 <ul>
 <li>There were no significant time lags between rearfoot/shank and <a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">hip</a> motions
 <ul>
 <li>Therefore, CC at k=0 determined coupling strengths</li>
 </ul>
 
 </li>
 <li>The mean CC between shank IR/ER and <a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">hip</a> IR/ER = 0.77 +/- 0.09
 <ul>
 <li>Strong mean temporal coupling, r-values ranging from moderate to strong</li>
 </ul>
 
 </li>
 <li>The mean CC between rearfoot INV/EV and <a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">hip</a> IR/ER = 0.56 +/- 0.14
 <ul>
 <li>Moderate mean temporal coupling, r-values between moderate and strong</li>
 </ul>
 
 </li>
 <li>PC between the timing of peak shank IR and peak <a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">hip</a> IR was statistically significant and moderate at 0.45 (p=0.031)</li>
 <li>PC between the timing of peak rearfoot EV and peak <a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">hip</a> IR was statistically significant and moderate at 0.62 (p=0.003)</li>
 </ul>
 </td>
 </tr>
 <tr>
 <td>Our Conclusions</td>
 <td>This study demonstrates the interdependence between the segments of the LE. It is interesting to note that peak rearfoot EV demonstrated a stronger association with <a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">hip</a> IR than peak shank IR. This study aids in the analysis of signs noted during the <a href="https://brookbushinstitute.com/article/introduction-overhead-squat-assessment" target="_blank" rel="noopener">overhead squat assessment</a>, specifically those associated with <a href="https://brookbushinstitute.com/article/lower-leg-dysfunction" target="_blank" rel="noopener">Lower Extremity Dysfunction (LED)</a>.</td>
 </tr>
 <tr>
 <td>Researchers&apos; Conclusions
 
 </td>
 <td>The findings suggest a temporal coupling of rearfoot pronation with <a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">hip</a> IR and rearfoot supination with <a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">hip</a> ER during the stance phase of gait. The variability of the temporal curves and moderate relationships between the timings of peak motion between subjects indicates that coupling strength should be clinically addressed on an individual basis.</td>
 </tr>
 </tbody>
</table>
<a href="https://brookbush.s3.us-east-2.amazonaws.com/wordpress/wp-content/uploads/2013/05/Robert-Griffin.jpg" target="_blank" rel="noopener"><img src="https://brookbush.s3.us-east-2.amazonaws.com/wordpress/wp-content/uploads/2013/05/Robert-Griffin.jpg" alt="Robert Griffin III during a vertical jump test his rookie year. Note his knees bow in, a.k.a. functional valgus."></a>
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.

This correlational study examined the relationship between shank internal/external rotation (IR/ER), rearfoot inversion/eversion (INV/EV), and <a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">hip</a> IR/ER during the stance phase of gait. Previous research investigating these relationships are limited by methodology. Several studies consider the foot a rigid segment (6-8), and one study did not consider possible time lags in motion at each joint (9). Unique to this study, the researcher considered pronation a combination of tibial/shank IR and calcaneal/rearfoot eversion, and accounted for time lags in the motion curves. These findings demonstrate that a moderate to strong correlation exists between foot, shank, and hip motion in the stance phase of gait.

The findings of this study correlate <a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">hip</a> and foot/<a href="https://brookbushinstitute.com/article/ankle-joint-talocrural-subtalor-tibiofibular-joints" target="_blank" rel="noopener">ankle</a> motion, demonstrating <a id="regional-interdependence" data-tip="1542" target="_blank" href="/glossary-term/regional-interdependence" class="glossary">regional interdependence</a> 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> segments. This suggests that patients/clients with <a href="https://brookbushinstitute.com/article/lower-leg-dysfunction" target="_blank" rel="noopener">Lower Extremity Dysfunction (LED)</a> should be assessed for <a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">hip</a> and foot/<a href="https://brookbushinstitute.com/article/ankle-joint-talocrural-subtalor-tibiofibular-joints" target="_blank" rel="noopener">ankle</a> impairments, regardless of the area of patient complaint or observed change in lower extremity motion. Further, human movement professionals should have a repertoire of techniques for addressing both hip and ankle impairments, and consider implementation for those with any symptoms/diagnoses related to <a href="https://brookbushinstitute.com/article/lower-leg-dysfunction" target="_blank" rel="noopener">Lower Extremity Dysfunction (LED)</a>.
This study had many methodological strengths, including:
<ul>
 <li>This study filled a gap in the body of research by demonstrating the relationship between the <a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">hip</a> and foot/<a href="https://brookbushinstitute.com/article/ankle-joint-talocrural-subtalor-tibiofibular-joints" target="_blank" rel="noopener">ankle</a> complex during the stance phase of gait. This relationship had been theorized but not yet supported by research.</li>
 <li>Validated procedures for the placement of kinematic markers were used, minimizing errors in data collection.</li>
 <li>This study investigated the shank/foot complex as two distinct movable joints allowing for analysis of the relationship between the talocrural and subtalar joints in relation to <a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">hip</a> motion prior to clinical <a id="integration" data-tip="1472" target="_blank" href="/glossary-term/integration" class="glossary">integration</a>. Prior studies considered the foot a single rigid segment.</li>
 <li>This study investigated young, healthy participants in order to establish predictive data for <a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">hip</a> and foot/<a href="https://brookbushinstitute.com/article/ankle-joint-talocrural-subtalor-tibiofibular-joints" target="_blank" rel="noopener">ankle</a> complex temporal relationships.</li>
</ul>
Weaknesses that should be noted prior to clinical <a id="integration" data-tip="1472" target="_blank" href="/glossary-term/integration" class="glossary">integration</a> of the findings include:
<ul>
 <li>The results of this study showed variability of the rearfoot to <a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">hip</a> coupling strengths; whereas, data from an increased number of participants may improve the results and establish <a id="normative-data" data-tip="1508" target="_blank" href="/glossary-term/normative-data" class="glossary">normative data</a>.</li>
 <li>Participants performed the walking task in trekking sandals with flat bases which may have limited the ability of the foot and LE <a id="kinetic-chain-2" data-tip="1544" target="_blank" href="/glossary-term/kinetic-chain-2" class="glossary">kinetic chain</a> to respond during walking; thus limiting the results.</li>
</ul>

The Brookbush Institute (BI) has developed <a href="https://brookbushinstitute.com/article/introduction-to-postural-dysfunction-and-movement-impairment" target="_blank" rel="noopener">predictive </a><a id="model" data-tip="1471" target="_blank" href="/glossary-term/model" class="glossary">models</a> of <a id="posture" data-tip="1659" target="_blank" href="/glossary-term/posture" class="glossary">postural</a> dysfunction based on evidence of common tissue changes (<a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a>, joint, fascia, and <a id="nerve-cell" data-tip="1361" target="_blank" href="/glossary-term/nerve-cell" class="glossary">nerve</a>) to aid human movement professionals in selecting <a id="optimal" data-tip="1571" target="_blank" href="/glossary-term/optimal" class="glossary">optimal</a> <a id="assessment" data-tip="1480" target="_blank" href="/glossary-term/assessment" class="glossary">assessments</a>, manual interventions, and exercise. This study demonstrates that 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; <a href="https://brookbushinstitute.com/glossary/osteokinematic-motion/" target="_blank" rel="noopener">osteokinematic</a> relationships similar to those described in the <a href="https://brookbushinstitute.com/article/lower-leg-dysfunction" target="_blank" rel="noopener">Lower Extremity Dysfunction (LED)</a>. Further, this study demonstrates the importance of a dynamic movement <a id="assessment" data-tip="1478" target="_blank" href="/glossary-term/assessment" class="glossary">assessment</a>, such as the <a href="https://brookbushinstitute.com/article/introduction-overhead-squat-assessment" target="_blank" rel="noopener">overhead squat assessment</a>, to determine compensation patterns including multiple joints.

<a href="https://brookbushinstitute.com/article/introduction-overhead-squat-assessment" target="_blank" rel="noopener">Overhead Squat Assessment</a> - Sign Clusters - Lower Leg Dysfunction
<iframe src="https://player.vimeo.com/video/109546175" frameborder="0" allowfullscreen="allowfullscreen"></iframe>
Dorsiflexion Goniometry:
<iframe src="https://player.vimeo.com/video/100952921" frameborder="0" allowfullscreen="allowfullscreen"></iframe>
Hip Internal Rotation Goneiometry:

<ol>
 <li>McPoil, T. G., &amp; Knecht, H. G. (1985). Biomechanics of the foot in walking: a function approach. Journal of Orthopaedic &amp; Sports Physical Therapy, 7(2), 69-72.</li>
 <li>Tiberio, D. (1988). Pathomechanics of structural foot deformities. Physical Therapy, 68(12), 1840-1849.</li>
 <li>Botte, R. R. (1981). An interpretation of the pronation syndrome and foot types of patients with low back pain. Journal of the American Podiatry Association, 71(5), 243-253.</li>
 <li>Fonseca, S. T., Ocarino, J. M., Silva, P. L. P., &amp; Aquino, C. F. (2007). Integration of stresses and their relationship to the kinetic chain. Scientific foundations and principles of practice in musculoskeletal rehabilitation. St Louis: Saunders Elsevier, 476-86.</li>
 <li>Gross, K. D., Niu, J., Zhang, Y. Q., Felson, D. T., McLennan, C., Hannan, M. T., &hellip; &amp; Hunter, D. J. (2007). Varus foot alignment and hip conditions in older adults. Arthritis &amp; Rheumatism: Official Journal of the American College of Rheumatology, 56(9), 2993-2998.</li>
 <li>Chiari, L., Della Croce, U., Leardini, A., &amp; Cappozzo, A. (2005). Human movement analysis using stereophotogrammetry: Part 2: Instrumental errors. Gait &amp; posture, 21(2), 197-211.</li>
 <li>Manal, K., McClay, I., Stanhope, S., Richards, J., &amp; Galinat, B. (2000). Comparison of surface mounted markers and attachment methods in estimating tibial rotations during walking: an in vivo study. Gait &amp; posture, 11(1), 38-45.</li>
 <li>Schache, A. G., Baker, R., &amp; Lamoreux, L. W. (2008). Influence of thigh cluster configuration on the estimation of hip axial rotation. Gait &amp; posture, 27(1), 60-69.</li>
 <li>Nester, C. (2000). The relationship between transverse plane leg rotation and transverse plane motion at the knee and hip during normal walking. Gait &amp; posture, 12(3), 251-256.</li>
 <li>Page, P., Frank, C., &amp; Lardner, R. (2010). Assessment and treatment of muscle imbalance: the Janda approach. Human kinetics.</li>
 <li>Clark, M., &amp; Lucett, S. (Eds.). (2010). NASM essentials of corrective exercise training. Lippincott Williams &amp; Wilkins.</li>
 <li>Neumann, D. A. (2010). Kinesiology of the musculoskeletal system: foundations for rehabilitation. St Louis, MO: Mosby. Elsevier.</li>
 <li>Sahrmann, S. (2002). Diagnosis and treatment of movement impairment syndromes. Elsevier Health Sciences.</li>
</ol>

Snyder et al. (2009). Training Hip Musculature Results in Improved Lower Extremity Biomechanics During Running

Original Citation: Snyder, K. R., Earl, J. E., O&#x2019;connor, K. M., &amp; Ebersole, K. T. (2009). Resistance training is accompanied by increases in hip strength and changes in lower extremity biomechanics during running. Clinical Biomechanics, 24(1), 26-34. - <a href="https://www.ncbi.nlm.nih.gov/pubmed/19013697" target="_blank" rel="noopener">ABSTRACT</a>
It is estimated that 10 million people in the United States run regularly, and approximately 50-75% will suffer injuries (1-3). Prior studies have correlated lower extremity over-use injuries with excessive hip adduction, abduction and/or internal rotation, as well as tibial external rotation and foot pronation (4-6). While research studies investigating the use of foot orthoses to correct mechanics have demonstrated mixed results (7-13), the impact of <a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">hip</a> strengthening had yet to be studied. This 2009 study by U.S. researchers demonstrated that a hip strengthening protocol improved knee and ankle range of motion. Human movement professionals working with runners should consider assessing hip abduction and external rotation strength and addressing any noted weakness prior to the development of an injury.
<a href="https://www.datocms-assets.com/25800/1646159461-hip-abduction-increased-glute-ma.jpeg"><img src="https://www.datocms-assets.com/25800/1646159461-hip-abduction-increased-glute-ma.jpeg"></a>Dr. Brookbush performing a Manual <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">Muscle</a> <a id="assessment" data-tip="1482" target="_blank" href="/glossary-term/assessment" class="glossary">Test</a> for Gluteus Maximus on a patient.

<table>
 <tbody>
 <tr>
 <td width="40%">Study Design</td>
 <td>Cohort Study - Within Subject Repeated Measures Design</td>
 </tr>
 <tr>
 <td>Level of Evidence</td>
 <td>IIB Evidence from at least one other type of quasi-experimental study</td>
 </tr>
 <tr>
 <td>Participant Characteristics</td>
 <td>Demographics
 <ul>
 <li>Age: 21.9 +/- 1.2 years</li>
 <li>Gender: female</li>
 <li>Number of participants:
 <ul>
 <li>13 for kinematic analysis</li>
 <li>14 for strength analysis</li>
 </ul>
 
 </li>
 </ul>
 Inclusion Criteria:
 <ul>
 <li>Activity level defined as moderate by the American College of Sports Medicine (ACSM) criteria (30 minutes of moderate intensity activity on most days of the week).</li>
 <li>Regular menstrual cycle</li>
 </ul>
 Exclusion Criteria:
 <ul>
 <li>&gt; 10 mm navicular drop</li>
 <li>History of orthopedic surgery in the lower extremity, injury to the lower extremity within the last 6 months, neurological impairment, or history of orthotic use.</li>
 </ul>
 </td>
 </tr>
 <tr>
 <td>Methodology</td>
 <td>
 <ul>
 <li>Participants were tested on hip abduction and external rotation strength via a mid-range isometric contraction.
 <ul>
 <li>Strength was measured on both the untrained and trained sides.</li>
 </ul>
 
 </li>
 <li>Joint range of motion (ROM), or kinematic data, during running was calculated from heel strike to peak angle.</li>
 <li>Joint moments, or kinetic data, were calculated via analysis of the body&apos;s response to external moments/forces through a force plate.</li>
 </ul>
 Intervention Protocol
 <ul>
 <li>3 closed kinematic chain (CKC) hip exercises utilizing a waist belt attached to a cable column for resistance.</li>
 <li>The protocol was performed 3 times per week for 6 weeks.</li>
 <li>The protocol required each participant to <a id="balance" data-tip="1190" target="_blank" href="/glossary-term/balance" class="glossary">balance</a> on the targeted lower extremity (LE) while performing <a id="specificity" data-tip="1224" target="_blank" href="/glossary-term/specificity" class="glossary">specific</a> tasks with the <a id="contralateral" data-tip="1549" target="_blank" href="/glossary-term/contralateral" class="glossary">contralateral</a> LE.
 <ul>
 <li>The dominant LE was used as the <a id="assessment" data-tip="1482" target="_blank" href="/glossary-term/assessment" class="glossary">test</a> extremity and was the right LE for all participants.</li>
 </ul>
 
 </li>
 <li>Exercise #1 - the &quot;TOWARD&quot; exercise: participants stood on the right LE facing the column with resistance <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>. The left LE was extended while the participant rotated their trunk counterclockwise, lightly touching their toe on the floor, and then controlled a slow return to the start position.</li>
 <li>Exercise #2 - the &quot;AWAY&quot; exercise: participants stood on the right LE facing the column with resistance <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>. The left LE was extended while the participant rotated their trunk counterclockwise, lightly touching their toe on the floor, and then controlled a slow return to the start position.</li>
 <li>Exercise #3 - the &quot;HIP HIKE&quot; exercise: participants stood on the right LE with the column beside the left LE, and raised the left side of the pelvis toward the ceiling and then slowly lowered it.</li>
 <li>For all exercises, initial resistance was set at 60% of 1 repetition maximum. Participants completed as many repetitions as possible with proper <a id="posture" data-tip="1660" target="_blank" href="/glossary-term/posture" class="glossary">form</a>, with verbal cuing provided as needed to maintain <a id="posture" data-tip="1660" target="_blank" href="/glossary-term/posture" class="glossary">form</a>. In subsequent training sessions, resistance was increased by 1.13 kg (2.5 lbs) if 12 repetitions were performed, and increased by 2.27 kg (5 lbs) if 30 or more repetitions were performed.</li>
 </ul>
 </td>
 </tr>
 <tr>
 <td>Data Collection and Analysis</td>
 <td>Data Collection
 <ul>
 <li>Strength testing and movement analyses were performed at pre-intervention, mid-point (3 weeks), and post-intervention (6 weeks).</li>
 <li>A handheld Lafayette Manual <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">Muscle</a> Testing System dynamometer was used to measure hip abduction and external rotation strength.</li>
 <li>Kinematic data was collected during running via a 7 camera Motion Analysis Eagle System.</li>
 <li>Kinetic data was collected using a force plate.</li>
 </ul>
 Data Analysis
 <ul>
 <li>Repeated measures analysis of variance (ANOVA) were used to identify changes in peak isometric hip abduction and external rotation forces at pre-, mid- and post-intervention.</li>
 <li>A separate ANOVA was performed on the kinematic variables during running between groups at pre-, mid- and post-intervention.</li>
 <li>A final ANOVA was performed to determine changes in the 4 joint moments investigated at pre-, mid- and post-intervention.</li>
 <li>Tukey&apos;s post-hoc <a id="assessment" data-tip="1482" target="_blank" href="/glossary-term/assessment" class="glossary">test</a> was performed to determine statistical differences.</li>
 <li>Statistical significance was set at P &#x2264; 0.05 for all analyses.</li>
 <li>Cohens d was used to report effect size of pre-test standard deviation.</li>
 </ul>
 </td>
 </tr>
 <tr>
 <td>Outcome Measures</td>
 <td>Strength
 <ul>
 <li><a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">Hip</a> abduction (ABD)</li>
 <li><a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">Hip</a> external rotation (ER)</li>
 </ul>
 Joint Range of Motion
 <ul>
 <li>Rearfoot eversion (EV)</li>
 <li>EV angle at heel strike</li>
 <li>Max EV velocity</li>
 <li>Knee ABD</li>
 <li><a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">Hip</a> adduction (ADD)</li>
 <li><a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">Hip</a> internal rotation (IR)</li>
 </ul>
 Joint Moments
 <ul>
 <li>Rearfoot inversion (INV)</li>
 <li>Knee ABD</li>
 <li><a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">Hip</a> ABD</li>
 <li><a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">Hip</a> ER</li>
 </ul>
 </td>
 </tr>
 <tr>
 <td>Results</td>
 <td>Strength
 <ul>
 <li><a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">Hip</a> ABD and ER were significantly stronger on the trained side at mid- and post-intervention testing.
 <ul>
 <li>Isometric ABD (F(2,26) = 5.68, P = 0.009)</li>
 <li>Isometric ER (F(2,26) = 11.23, P &lt; 0.0005)</li>
 <li>Tukey&apos;s post-hoc <a id="assessment" data-tip="1482" target="_blank" href="/glossary-term/assessment" class="glossary">test</a> (P &#x2264; 0.05)</li>
 </ul>
 
 </li>
 <li>No additional strength gains occurred between mid- and post-intervention testing for either <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> group.</li>
 </ul>
 Kinematics
 <ul>
 <li>Rearfoot EV was significantly reduced (F(2,24) = 3.38, P = 0.05)</li>
 <li>Trend of reduced <a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">hip</a> IR, but not statistically significant (F(2,24) = 2.86, P = 0.08)</li>
 <li><a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">Hip</a> ADD significantly increased (F(2,24) = 3.29, P = 0.05)</li>
 <li>No statistically significant differences in EV angle at heel strike, EV velocity or knee ABD ROM.</li>
 </ul>
 Joint Moments
 <ul>
 <li>Rearfoot INV and knee ABD moments were significantly reduced.
 <ul>
 <li>Rearfoot INV moment (F(2,26) = 8.16, P = 0.02)</li>
 <li>Knee ABD moment (F(2,26) = 3.24, P = 0.05)</li>
 </ul>
 
 </li>
 <li><a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">Hip</a> ABD and ER moments were not significantly different.</li>
 </ul>
 </td>
 </tr>
 <tr>
 <td>Our Conclusions</td>
 <td>The results of this study demonstrate a relationship between <a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">hip</a> ABD and ER strength, and knee and <a href="https://brookbushinstitute.com/article/ankle-joint-talocrural-subtalor-tibiofibular-joints" target="_blank" rel="noopener">ankle</a> range of motion (ROM) during running. This implies interdependence between the segments of the LE, as has been proposed in the Brookbush Institute&apos;s model of <a href="https://brookbushinstitute.com/article/lower-leg-dysfunction" target="_blank" rel="noopener">Lower Extremity Dysfunction (LED)</a>. Further, this study supports the incorporation of stability integration exercises as part of an integrated approach to treatment.</td>
 </tr>
 <tr>
 <td>Researchers&apos; Conclusions
 
 </td>
 <td>The strengthening protocol used in this study demonstrate statistically significant improvements were made in <a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">hip</a> ABD and ER strength, leading to altered LE joint mechanics during running. The alterations in running mechanics included a reduction in rearfoot EV and <a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">hip</a> IR. The use of hip external rotation and extension strengthening should be considered in pre-habilitation and rehabilitation programs for runners.</td>
 </tr>
 </tbody>
</table>
<a href="https://www.datocms-assets.com/25800/1646159517-hip-and-abdominal-strengthening.jpeg"><img src="https://www.datocms-assets.com/25800/1646159517-hip-and-abdominal-strengthening.jpeg"></a>
Hip abduction with manual resistance. (Image: Courtesy of www.BrentBrookbush.com)

The relationships between overuse injuries in runners and <a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">hip</a>, knee and <a href="https://brookbushinstitute.com/article/ankle-joint-talocrural-subtalor-tibiofibular-joints" target="_blank" rel="noopener">ankle</a> kinematics, highlights the interdependence of lower extremity (LE) joints and muscles (4-6). Previous research on foot orthoses and <a href="https://brookbushinstitute.com/article/ankle-joint-talocrural-subtalor-tibiofibular-joints" target="_blank" rel="noopener">ankle</a> strengthening programs have shown mixed results in their ability to control LE frontal and transverse plane motion (7-13). Unique to this study, the researchers investigated a closed-chain <a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">hip</a> abduction (ABD) and external rotation (ER) strengthening protocol on LE joint ROM. This study demonstrates a correlation between an increase in <a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">hip</a> ABD and ER strength and a reduction in ankle eversion and hip internal rotation during running.

The findings of this study demonstrate the <a href="https://brookbushinstitute.com/glossary/regional-interdependence/" target="_blank" rel="noopener">regional interdependence</a> of joints of the lower extremity. This suggests that patients/clients with <a href="https://brookbushinstitute.com/article/lower-leg-dysfunction" target="_blank" rel="noopener">Lower Extremity Dysfunction (LED)</a> should be assessed for <a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">hip</a> impairments, as well as ankle and knee impairments, regardless of the area of patient complaint or injury. Further, human movement professionals should consider using <a href="https://brookbushinstitute.com/video/single-leg-balance-with-reach-excursion" target="_blank" rel="noopener">single-leg </a><a id="balance" data-tip="1190" target="_blank" href="/glossary-term/balance" class="glossary">balance</a> with resisted excursion as a component of a hip-strengthening program
This study had many methodological strengths, including:
<ul>
 <li>This study filled a gap in the body of research by demonstrating the relationship between <a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">hip</a> strengthening and improved knee and <a href="https://brookbushinstitute.com/article/ankle-joint-talocrural-subtalor-tibiofibular-joints" target="_blank" rel="noopener">ankle</a> motion during running. This relationship had been theorized but not yet supported by research.</li>
 <li>The researchers used <a id="reliability" data-tip="1795" target="_blank" href="/glossary-term/reliability" class="glossary">reliable</a> <a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">hip</a> ABD and ER strength testing methods as demonstrated by a previous study (14) and the calculation of intra-class correlation coefficients in the current study.</li>
 <li><a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">Hip</a> ABD and ER strength testing was performed on the trained and untrained extremities to investigate any cross-over training effects that may have occurred.</li>
 <li>The researchers included exercises in the strengthening program that have been shown to produce high levels of electromyographic (EMG) activity in the <a href="https://brookbushinstitute.com/article/gluteus-medius" target="_blank" rel="noopener">gluteus medius</a> (15).</li>
 <li>One repetition maximum tests were performed every 2 weeks throughout the training program to monitor and progress loads.</li>
 <li>The researchers performed an a priori <a id="power" data-tip="1399" target="_blank" href="/glossary-term/power" class="glossary">power</a> analysis based on previous studies to achieve a statistical <a id="power" data-tip="1399" target="_blank" href="/glossary-term/power" class="glossary">power</a> of 0.80, and exceeded the number of needed participants in the study.</li>
</ul>
Weaknesses that should be noted prior to the clinical <a id="integration" data-tip="1472" target="_blank" href="/glossary-term/integration" class="glossary">integration</a> of the findings include:
<ul>
 <li>The researchers noted that <a id="posture" data-tip="1659" target="_blank" href="/glossary-term/posture" class="glossary">postural</a> compensations were observed as resistance increased, despite verbal cueing.</li>
 <li>The researchers did not incorporate EMG data in their analysis, which would have provided information on changes in <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> activity as a result of the intervention and on potential compensation patterns during training.</li>
 <li>The functional task (running), strength testing, and training protocols were not matched relative to <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> contraction and timing. Future research involving isokinetic strength measurements at various speeds would <a id="assessment" data-tip="1486" target="_blank" href="/glossary-term/assessment" class="glossary">assess</a> strength gains more <a id="specificity" data-tip="1224" target="_blank" href="/glossary-term/specificity" class="glossary">specific</a> to running.</li>
</ul>

The Brookbush Institute (BI) has developed <a href="https://brookbushinstitute.com/article/introduction-to-postural-dysfunction-and-movement-impairment" target="_blank" rel="noopener">predictive </a><a id="model" data-tip="1471" target="_blank" href="/glossary-term/model" class="glossary">models</a> of <a id="posture" data-tip="1659" target="_blank" href="/glossary-term/posture" class="glossary">postural</a> dysfunction based on evidence of common tissue changes (<a href="https://brookbushinstitute.com/glossary/muscle-cell/" target="_blank" rel="noopener">muscle</a>, joint, fascia, and <a href="https://brookbushinstitute.com/glossary/nerve-cell/" target="_blank" rel="noopener">nerve</a>) to aid human movement professionals in selecting <a href="https://brookbushinstitute.com/glossary/optimal/" target="_blank" rel="noopener">optimal</a> <a href="https://brookbushinstitute.com/glossary/assessment/" target="_blank" rel="noopener">assessments</a>, manual interventions, and exercise. This study demonstrates that increases in <a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">hip</a> ABD and ER strength improves knee and <a href="https://brookbushinstitute.com/article/ankle-joint-talocrural-subtalor-tibiofibular-joints" target="_blank" rel="noopener">ankle</a> motion during running; biomechanical changes similar to those described in the <a href="https://brookbushinstitute.com/article/lower-leg-dysfunction" target="_blank" rel="noopener">Lower Extremity Dysfunction (LED)</a>. As shown in the <a href="https://brookbushinstitute.com/article/lower-leg-corrective-exercise-and-sample-routine" target="_blank" rel="noopener">Lower Leg Dysfunction: Corrective Exercise and Sample Routine</a>, the BI recommends an <a id="integration" data-tip="1473" target="_blank" href="/glossary-term/integration" class="glossary">integrated</a> approach that addresses impairments in the following order: <a id="release" data-tip="1249" target="_blank" href="/glossary-term/release" class="glossary">release</a>, mobilize, lengthen (stretch), isolated activation, core <a id="base-of-support" data-tip="1197" target="_blank" href="/glossary-term/base-of-support" class="glossary">support</a>, <a id="stability" data-tip="1191" target="_blank" href="/glossary-term/stability" class="glossary">stability</a> <a id="integration" data-tip="1472" target="_blank" href="/glossary-term/integration" class="glossary">integration</a>, reactive <a id="integration" data-tip="1472" target="_blank" href="/glossary-term/integration" class="glossary">integration</a>, and subsystem <a id="integration" data-tip="1472" target="_blank" href="/glossary-term/integration" class="glossary">integration</a>. The exercises described in this study are good examples of what BI refers to as &quot;stability <a id="integration" data-tip="1472" target="_blank" href="/glossary-term/integration" class="glossary">integration</a>.&quot;

Single-Leg <a id="balance" data-tip="1190" target="_blank" href="/glossary-term/balance" class="glossary">Balance</a> with Excursion
<iframe src="https://player.vimeo.com/video/76717841" frameborder="0" allowfullscreen="allowfullscreen"></iframe>
Resisted Single-Leg Balance:
<iframe src="https://player.vimeo.com/video/82871943" frameborder="0" allowfullscreen="allowfullscreen"></iframe>
Single-Leg Chop Pattern
<iframe src="https://player.vimeo.com/video/267503968" frameborder="0" allowfullscreen="allowfullscreen"></iframe>
Single-Leg Touchdown
<iframe src="https://player.vimeo.com/video/76719459" frameborder="0" allowfullscreen="allowfullscreen"></iframe>
Single-Leg Deadlift Touchdown with <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> Pull
<iframe src="https://player.vimeo.com/video/121109135" frameborder="0" allowfullscreen="allowfullscreen"></iframe>

<ol>
 <li>Kaufman, K. R., Brodine, S. K., Shaffer, R. A., Johnson, C. W., &amp; Cullison, T. R. (1999). The effect of foot structure and range of motion on musculoskeletal overuse injuries. The American journal of sports medicine, 27(5), 585-593.</li>
 <li>Van Mechelen, W. (1992). Running injuries. Sports Medicine, 14(5), 320-335.</li>
 <li>Taunton, J. E., Ryan, M. B., Clement, D. B., McKenzie, D. C., Lloyd-Smith, D. R., &amp; Zumbo, B. D. (2002). A retrospective case-control analysis of 2002 running injuries. British journal of sports medicine, 36(2), 95-101.</li>
 <li>Munteanu, S. E., &amp; Barton, C. J. (2011). Lower limb biomechanics during running in individuals with achilles tendinopathy: a systematic review. Journal of foot and ankle research, 4(1), 15.</li>
 <li>Ireland, M. L. (2002). The female ACL: why is it more prone to injury?. Orthopedic Clinics, 33(4), 637-651.</li>
 <li>Powers, C. M. (2003). The influence of altered lower-extremity kinematics on patellofemoral joint dysfunction: a theoretical perspective. Journal of Orthopaedic &amp; Sports Physical Therapy, 33(11), 639-646.</li>
 <li>Baitch, S. P., Blake, R. L., Fineagan, P. L., &amp; Senatore, J. (1991). Biomechanical analysis of running with 25 degrees inverted orthotic devices. Journal of the American Podiatric Medical Association, 81(12), 647-652.</li>
 <li>Bates, B. T., Osternig, L. R., Mason, B., &amp; James, L. S. (1979). Foot orthotic devices to modify selected aspects of lower extremity mechanics. The American journal of sports medicine, 7(6), 338-342.</li>
 <li>Smith, L. S., Clarke, T. E., Hamill, C. L., &amp; Santopietro, F. (1986). The effects of soft and semi-rigid orthoses upon rearfoot movement in running. Journal of the American Podiatric Medical Association, 76(4), 227-233.</li>
 <li>Nawoczenski, D. A., Cook, T. M., &amp; Saltzman, C. L. (1995). The effect of foot orthotics on three-dimensional kinematics of the leg and rearfoot during running. Journal of Orthopaedic &amp; Sports Physical Therapy, 21(6), 317-327.</li>
 <li>Stackhouse, C. L., Davis, I. M., &amp; Hamill, J. (2004). Orthotic intervention in forefoot and rearfoot strike running patterns. Clinical Biomechanics, 19(1), 64-70.</li>
 <li>Stacoff, A., Reinschmidt, C., Nigg, B. M., van den Bogert, A. J., Lundberg, A., Denoth, J., &amp; St&uuml;ssi, E. (2000). Effects of foot orthoses on skeletal motion during running. Clinical Biomechanics, 15(1), 54-64.</li>
 <li>Feltner, M. E., MacRae, H. S., Macrae, P. G., Turner, N. S., Hartman, C. A., Summers, M. L., &amp; Welch, M. D. (1994). Strength training effects on rearfoot motion in running. Medicine and science in sports and exercise, 26(8), 1021-1027.</li>
 <li>Ireland, M. L., Willson, J. D., Ballantyne, B. T., &amp; Davis, I. M. (2003). Hip strength in females with and without patellofemoral pain. Journal of orthopaedic &amp; sports physical therapy, 33(11), 671-676.</li>
 <li>Earl, J. E. (2005). Gluteus medius activity during 3 variations of isometric single-leg stance. Journal of Sport Rehabilitation, 14(1), 1-11.</li>
</ol>

&copy; 2018 Brent Brookbush
Questions, comments and criticisms are welcomed and encouraged

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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