Introduction

Practical Application

Research Corner Abdominal Fascia

Research Corner Rectus Abdominis

Research Corner External Obliques

Anterior Adductors

Pectoralis Major

Serratus Anterior

Summary of Research Findings

More on Function

Anterior Oblique Subsystem (AOS)

NASM

ACSM

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NCBTMB

CanFitPro

PTAGlobal

ISSA

REPS

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PACE

YOGA

WITS

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Anterior Oblique Subsystem Integration

This course describes the <a id="anterior" data-tip="1566" target="_blank" href="/glossary-term/anterior" class="glossary">anterior</a> oblique subsystem (AOS). The <a id="anterior" data-tip="1566" target="_blank" href="/glossary-term/anterior" class="glossary">anterior</a> oblique subsystem may also be referred to as the <a id="anterior" data-tip="1566" target="_blank" href="/glossary-term/anterior" class="glossary">anterior</a> oblique sling, oblique sling, <a id="anterior" data-tip="1566" target="_blank" href="/glossary-term/anterior" class="glossary">anterior</a> oblique myofascial synergy, and is similar to the concepts of <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> synergies, myofascial lines, myofascial trains, anatomy trains, myofascial meridians, superficial front line, functional line, spiral line, and the serape effect. This course covers a detailed analysis of the <a id="anterior" data-tip="1566" target="_blank" href="/glossary-term/anterior" class="glossary">anterior</a> oblique subsystem (sling) including anatomy, research, <a id="integration" data-tip="1472" target="_blank" href="/glossary-term/integration" class="glossary">integration</a> techniques and a sample routine.
<h4>The Anterior Oblique Subsystem (AOS) is comprised of:</h4>
<ul>
 <li><a href="https://brookbushinstitute.com/courses/rectus-abdominis-pyramidalis">Rectus abdominis and pyramidalis</a></li>
 <li>Abdominal Fascia (<a id="anterior" data-tip="1566" target="_blank" href="/glossary-term/anterior" class="glossary">Anterior</a> layer)</li>
 <li><a href="https://brookbushinstitute.com/courses/external-obliques">External Obliques</a></li>
 <li><a href="https://brookbushinstitute.com/courses/adductors">Anterior Adductors</a>
 <ul>
 <li>Potentially
 <ul>
 <li><a href="https://brookbushinstitute.com/courses/pectoralis-major">Pectoralis Major</a></li>
 <li><a href="https://brookbushinstitute.com/courses/serratus-anterior">Serratus Anterior</a></li>
 </ul>
 </li>
 </ul>
 </li>
</ul>
The concepts and techniques described in this course may be particularly beneficial for neuromuscular re-education, coordination, motor pattern <a id="integration" data-tip="1472" target="_blank" href="/glossary-term/integration" class="glossary">integration</a>, whole-body strength, functional strength, and sports performance. Sports medicine professionals (personal trainers, fitness instructors, physical therapists, massage therapists, chiropractors, occupational therapists, athletic trainers, etc.) should consider adding these exercises to their repertoire to improve the outcomes of their <a id="integration" data-tip="1473" target="_blank" href="/glossary-term/integration" class="glossary">integrated</a> exercise programs, sports performance programs, and therapeutic (rehabilitation) interventions.
<h4>For additional self-administered joint mobilization techniques check out:</h4>
<ul>
 <li><a href="https://brookbushinstitute.com/courses/intrinsic-stabilization-subsystem">Intrinsic Stabilization Subsystem (ISS)</a></li>
 <li><a href="https://brookbushinstitute.com/courses/posterior-oblique-subsystem-pos">Posterior Oblique Subsystem (POS)</a></li>
 <li><a href="https://brookbushinstitute.com/courses/deep-longitudinal-subsystem">Deep Longitudinal Subsystem (DLS)</a></li>
</ul>

Course Description: Anterior Oblique Subsystem

<h3><a href="https://www.datocms-assets.com/25800/1684183329-anterior-oblique-subsystem-study-guide-pdf.pdf" title="Quick Study Guide: Anterior Oblique Subsystem (AOS)">Quick Study Guide: Anterior Oblique Subsystem (AOS)</a></h3>
<h3>Function (Brief):</h3>
The muscles that comprise the AOS are the global movers of the <a id="anterior" data-tip="1566" target="_blank" href="/glossary-term/anterior" class="glossary">anterior</a> trunk and the <a href="https://brookbushinstitute.com/courses/adductors" target="_blank" rel="noopener">adductors.</a> This subsystem plays a significant role in stabilizing the thoracic and lumbar spine, sacroiliac joint (SIJ), pubic symphysis, and <a href="https://brookbushinstitute.com/courses/hip-joint" target="_blank" rel="noopener">hip</a>, as well as transferring force between lower and upper extremities. The AOS plays an active role in all pushing and rotational movement patterns (especially turning in), multi-segmental flexion, and eccentrically decelerating spinal extension and rotation, as well as hip extension, abduction, and external rotation (<a href="https://brookbushinstitute.com/video/overhead-squat-assessment-6-knees-bow-in-breakdown" target="_blank" rel="noopener">knees bow in</a> and <a href="https://brookbushinstitute.com/video/overhead-squat-assessment-8-excessive-forward-lean" target="_blank" rel="noopener">excessive forward lean</a>). The AOS is the functional <a id="antagonists" data-tip="1705" target="_blank" href="/glossary-term/antagonists" class="glossary">antagonist</a> of the <a href="https://brookbushinstitute.com/courses/posterior-oblique-subsystem-pos" target="_blank" rel="noopener">Posterior Oblique Subsystems (POS)</a>.
The muscles of the <a id="anterior" data-tip="1566" target="_blank" href="/glossary-term/anterior" class="glossary">anterior</a> oblique subsystem which includes external obliques and adductors
<ul>
 <li> Concentric Function: Pushing, rotation &quot;inward&quot;, multi-segmental flexion</li>
 <li> Isometric Function: Transfer force between lower and upper extremities, stabilization of the SIJ, pubic symphysis thoracic and lumbar spine and <a href="https://brookbushinstitute.com/courses/hip-joint" target="_blank" rel="noopener">hips </a></li>
 <li> Eccentric Function: Decelerate spine extension and rotation, as well as hip extension, abduction, and external rotation</li>
</ul>
<h3> Common Maladaptive Behavior </h3>
<ul>
 <li>Over-active</li>
</ul>

Introduction: Anterior Oblique Subsystem (Sling)

<h3>Signs of AOS Dysfunction </h3>
<ul>
 <li> <a href="https://brookbushinstitute.com/courses/solutions-table-overhead-squat-assessment">Overhead Squat Assessment</a> (OHSA)
 <ul>
 <li><a href="https://brookbushinstitute.com/video/overhead-squat-assessment-10-arms-fall" target="_blank" rel="noopener"> Arms Fall </a></li>
 <li><a href="https://brookbushinstitute.com/video/overhead-squat-assessment-11-shoulders-elevate" target="_blank" rel="noopener"> Shoulders Elevate </a></li>
 <li><a href="https://brookbushinstitute.com/video/overhead-squat-assessment-9-anterior-pelvic-tilt-excessive-lordosis" target="_blank" rel="noopener"> Excessive lordosis </a></li>
 <li><a href="https://brookbushinstitute.com/video/overhead-squat-assessment-8-excessive-forward-lean" target="_blank" rel="noopener"> Excessive forward lean </a></li>
 <li><a href="https://brookbushinstitute.com/video/overhead-squat-assessment-6-knees-bow-in-breakdown" target="_blank" rel="noopener"> Knees bow in</a></li>
 <li><a href="https://brookbushinstitute.com/videos/overhead-squat-assessment-13-sign-clusters-upper-body-dysfunction" title="OHSA Upper Body Dysfunction" target="_blank" rel="noopener">OHSA with Modification: Arm Down -&#xA0; Excessive Trunk Flexion</a></li>
 </ul>
 <a href="https://brookbushinstitute.com/videos/overhead-squat-assessment-13-sign-clusters-upper-body-dysfunction" title="OHSA Upper Body Dysfunction" target="_blank" rel="noopener"> </a>
 </li>
</ul>
<img title="Knee valgus (functional valgus) during squats, running, and landing" src="https://www.datocms-assets.com/25800/1650308470-knee-valgus.jpeg" alt="Example of knee valgus (knee bow in)">
<h3> Practical Application </h3>
<ul>
 <li> Core 
 <ul>
 <li><a href="https://brookbushinstitute.com/courses/chop-pattern-progressions" target="_blank" rel="noopener"> Static Chop and </a><a id="exercise-progression" data-tip="1184" target="_blank" href="/glossary-term/exercise-progression" class="glossary">Progression</a> </li>
 <li><a href="https://brookbushinstitute.com/courses/plank-progression" target="_blank" rel="noopener"> Planks and </a><a id="exercise-progression" data-tip="1182" target="_blank" href="/glossary-term/exercise-progression" class="glossary">Progressions</a> </li>
 </ul>
 </li>
 <li> <a id="integration" data-tip="1473" target="_blank" href="/glossary-term/integration" class="glossary">Integrated</a> Exercise 
 <ul>
 <li>Legs with Push</li>
 </ul>
 </li>
</ul>

Signs of AOS Dysfunction 

<ul>
 <li>
 <h4> <a id="mobility" data-tip="1455" target="_blank" href="/glossary-term/mobility" class="glossary">Mobility</a> </h4>
 <ul>
 <li>Release
 <ul>
 <li><a href="https://brookbushinstitute.com/video/tensor-fascia-latae-tfl-self-administered-release" target="_blank" rel="noopener"> Tensor fascia latae (TFL) </a><a id="release" data-tip="1249" target="_blank" href="/glossary-term/release" class="glossary">Release</a> </li>
 <li><a href="https://brookbushinstitute.com/video/gluteus-minimus-sa-release" target="_blank" rel="noopener"> Gluteus minimus </a><a id="release" data-tip="1249" target="_blank" href="/glossary-term/release" class="glossary">Release</a> </li>
 <li><a href="https://brookbushinstitute.com/video/vastus-lateralis-sa-static-release" target="_blank" rel="noopener"> Vastus lateralis </a><a id="release" data-tip="1249" target="_blank" href="/glossary-term/release" class="glossary">Release</a> </li>
 <li><a href="https://brookbushinstitute.com/video/rectus-femoris-sa-static-release" target="_blank" rel="noopener"> Rectus femoris </a><a id="release" data-tip="1249" target="_blank" href="/glossary-term/release" class="glossary">Release</a> </li>
 </ul>
 </li>
 <li>Mobilization
 <ul>
 <li><a href="https://brookbushinstitute.com/video/hip-mobilization" target="_blank" rel="noopener"> Self-administered hip mobilization </a></li>
 </ul>
 </li>
 <li>Lengthen
 <ul>
 <li><a href="https://brookbushinstitute.com/video/kneeling-hip-flexor-static-stretch" target="_blank" rel="noopener"> Kneeling hip flexor static stretch </a></li>
 </ul>
 </li>
 </ul>
 </li>
 <li>
 <h4> Activity </h4>
 <ul>
 <li>Isolated Activation
 <ul>
 <li><a href="https://brookbushinstitute.com/video/quick-glute-activation-circuit" target="_blank" rel="noopener"> Glute activation circuit </a></li>
 </ul>
 </li>
 <li> Core 
 <ul>
 <li> <a href="https://brookbushinstitute.com/video/kneeling-chop-pattern" target="_blank" rel="noopener">Kneeling Chop Pattern</a> (AOS)</li>
 <li><a href="https://brookbushinstitute.com/video/ultimate-glute-bridge" target="_blank" rel="noopener"> Ultimate Glute Bridge</a> (POS)</li>
 </ul>
 </li>
 <li>Subsystem <a id="integration" data-tip="1472" target="_blank" href="/glossary-term/integration" class="glossary">Integration</a> 
 <ul>
 <li> <a href="https://brookbushinstitute.com/video/anterior-oblique-subsystem-integration-step-up-to-chest-press" target="_blank" rel="noopener"> Step-up to Press</a> (AOS)</li>
 <li><a href="https://brookbushinstitute.com/video/squat-to-row-posterior-oblique-subsystem-integration" target="_blank" rel="noopener"> Squat to Row</a> (POS)</li>
 </ul>
 </li>
 </ul>
 </li>
</ul>

Sample Program (Anterior Pelvic Tilt)

Research Corner 

<div tabindex="0">
 <div tabindex="0">
 The rectus sheath envelopes the <a href="https://brookbushinstitute.com/courses/rectus-abdominis-pyramidalis" target="_blank" rel="noopener">rectus abdominis</a> <a href="https://brookbushinstitute.com/glossary/anterior/" target="_blank" rel="noopener">anteriorly</a> and <a href="https://brookbushinstitute.com/glossary/posterior/" target="_blank" rel="noopener">posteriorly</a>. From costal cartilage to the arcuate line (the level of the umbilicus), the <a href="https://brookbushinstitute.com/glossary/anterior/" target="_blank" rel="noopener">anterior</a> sheath is comprised of a continuation of the <a href="https://brookbushinstitute.com/courses/external-obliques" target="_blank" rel="noopener">external oblique </a>fascia while the <a href="https://brookbushinstitute.com/glossary/posterior/" target="_blank" rel="noopener">posterior</a> sheath is comprised of a continuation of the <a href="https://brookbushinstitute.com/courses/internal-obliques" target="_blank" rel="noopener">internal oblique</a> and transverse abdominis fascia(1). Below the level of the arcuate line, the <a href="https://brookbushinstitute.com/glossary/posterior/" target="_blank" rel="noopener">posterior</a> sheath does not continue, and the fascia of the <a href="https://brookbushinstitute.com/courses/internal-obliques" target="_blank" rel="noopener">internal obliques</a>, <a href="https://brookbushinstitute.com/courses/external-obliques" target="_blank" rel="noopener">external obliques</a>, and transverse abdominis continue <a href="https://brookbushinstitute.com/glossary/anterior/" target="_blank" rel="noopener">anteriorly</a> to the <a href="https://brookbushinstitute.com/courses/rectus-abdominis-pyramidalis" target="_blank" rel="noopener">rectus abdominis</a>. The fusion of the layers of the abdominal fascia below the arcuate line may serve as a fascial connection between the <a id="anterior" data-tip="1566" target="_blank" href="/glossary-term/anterior" class="glossary">anterior</a> abdominal fascia of the AOS, and the middle and <a id="posterior" data-tip="1565" target="_blank" href="/glossary-term/posterior" class="glossary">posterior</a> layers of abdominal fascia of the <a href="https://brookbushinstitute.com/courses/intrinsic-stabilization-subsystem" target="_blank" rel="noopener">Intrinsic Stabilization Subsystem (ISS)</a>.
 The fascial layers of the abdomen converge at the linea alba, where they continue into identical fascial sheaths on the opposite side. The linea alba, running vertically between the two <a href="https://brookbushinstitute.com/courses/rectus-abdominis-pyramidalis" target="_blank" rel="noopener">rectus abdominis</a> muscles, is a thickening created by the union of the transverse fibers of the fascial sheaths from either side (2). The transverse inscriptions that run horizontally through the <a href="https://brookbushinstitute.com/courses/rectus-abdominis-pyramidalis" target="_blank" rel="noopener">rectus abdominis</a> are also continuations of the oblique fascia (3). In addition, fascia from the sternal fibers of the <a href="https://brookbushinstitute.com/courses/pectoralis-major" target="_blank" rel="noopener">pectoralis major</a> and the fascia of the <a href="https://brookbushinstitute.com/courses/serratus-anterior" target="_blank" rel="noopener">serratus anterior</a> invests in the fascia of the <a href="https://brookbushinstitute.com/courses/external-obliques" target="_blank" rel="noopener">external obliques</a> (and sometimes <a href="https://brookbushinstitute.com/courses/rectus-abdominis-pyramidalis" target="_blank" rel="noopener">rectus abdominis</a>)(1, 4-7). These findings expand the original description of the AOS as described by Vleeming et al. (1) to include two powerful upper extremity muscles.
 Relative to function, any significant <a href="https://brookbushinstitute.com/glossary/lateral/" target="_blank" rel="noopener">lateral</a>, <a href="https://brookbushinstitute.com/glossary/posterior/" target="_blank" rel="noopener">posterior</a>, or rotational force imparted on the trunk will result in an increase in <a href="https://brookbushinstitute.com/courses/rectus-abdominis-pyramidalis" target="_blank" rel="noopener">rectus abdominis</a>, <a href="https://brookbushinstitute.com/courses/rectus-abdominis-pyramidalis" target="_blank" rel="noopener">pyramidalis</a>, <a href="https://brookbushinstitute.com/courses/external-obliques" target="_blank" rel="noopener"> external obliques,</a> <a href="https://brookbushinstitute.com/courses/internal-obliques" target="_blank" rel="noopener">internal obliques</a>, and transverse abdominis activity (recruitment of the AOS and ISS ) (2), and may increase quadratus lumborum and psoas activity (7-9). This increase in <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> activity will also increase <a id="tension" data-tip="1229" target="_blank" href="/glossary-term/tension" class="glossary">tension</a> of the abdominal fascia, transverse inscriptions, and linea alba. Studies show that force imparted by a trunk <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> will be transmitted between all layers of abdominal fascial network (10, 11). This may imply that <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> recruitment and/or fascial <a id="tension" data-tip="1229" target="_blank" href="/glossary-term/tension" class="glossary">tension</a> may signal an increase in the other. Studies on the amount any <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> can displace a layer of abdominal fascia are not available as they are for the thoracolumbar fascia (TLF) (10); however, Vleeming makes the following analogy (6) &#x2013; The abdominal fascia features muscles encased in a fascial network, much like the TLF. The paired <a href="https://brookbushinstitute.com/courses/rectus-abdominis-pyramidalis" target="_blank" rel="noopener">rectus abdominis</a> muscles are encased in the fascia of investing muscles (<a href="https://brookbushinstitute.com/courses/transverse-abdominis" target="_blank" rel="noopener">transverse abdominis</a>, <a href="https://brookbushinstitute.com/courses/internal-obliques" target="_blank" rel="noopener"> internal obliques</a>, and <a href="https://brookbushinstitute.com/courses/external-obliques" target="_blank" rel="noopener">external obliques</a>). <a id="tension" data-tip="1229" target="_blank" href="/glossary-term/tension" class="glossary">tension</a> in these muscles increases <a id="tension" data-tip="1229" target="_blank" href="/glossary-term/tension" class="glossary">tension</a> in the abdominal fascia like the<a href="https://brookbushinstitute.com/courses/latissimus-dorsi" target="_blank" rel="noopener"> latissimus dorsi</a> and <a href="https://brookbushinstitute.com/courses/gluteus-maximus" target="_blank" rel="noopener">gluteus maximus</a> increases <a id="tension" data-tip="1229" target="_blank" href="/glossary-term/tension" class="glossary">tension</a> in the TLF.
 Only one study could be located that may imply the efficacy of a technique directed at the abdominal fascia. In this study, deep, slow pressure resulted in a decrease in <a href="https://brookbushinstitute.com/glossary/muscle-cell/" target="_blank" rel="noopener">muscle</a> activity (5). Admittedly, this is not a common or comfortable technique to apply to the abdomen. If manual pressure is applied, a tangential force is recommended to reduce discomfort. No studies could be located that investigated instrument-assisted soft tissue mobilization (IASTM) on the abdominal region, but based on the idea that <a href="https://brookbushinstitute.com/glossary/glide/" target="_blank" rel="noopener">shear</a> between layers may be reduced as a result of dysfunction, careful application in practice may be warranted, especially where the layers converge at the semilunar lines and <a href="https://brookbushinstitute.com/glossary/lateral/" target="_blank" rel="noopener">lateral</a> raphe of the TLF.
 <a href="https://brookbush.s3.us-east-2.amazonaws.com/wordpress/wp-content/uploads/2016/12/TVA-image.png" target="_blank" rel="noopener"> <img src="https://brookbush.s3.us-east-2.amazonaws.com/wordpress/wp-content/uploads/2016/12/TVA-image.png" alt="Image of Transverse Abdominis and Rectus Abdominis" title="Transverse abdominis and abdominal fascia"> </a>
 Modified image from Gray&apos;s Anatomy - https://en.wikipedia.org/wiki/Transverse_abdominal_muscle
 </div>
</div>

Abdominal Fascia (Anterior Layer)

<div tabindex="0">
 <div tabindex="0">
 The <a href="https://brookbushinstitute.com/courses/rectus-abdominis-pyramidalis" target="_blank" rel="noopener">rectus abdominis</a> may enhance rigidity or aid in transferring force between the left and right sides of the abdominal fascia; however, the relationship between the <a href="https://brookbushinstitute.com/courses/rectus-abdominis-pyramidalis" target="_blank" rel="noopener">rectus abdominis</a> and the abdominal fascia has not been well-researched. The proximity and continuity of the <a href="https://brookbushinstitute.com/courses/rectus-abdominis-pyramidalis" target="_blank" rel="noopener">rectus abdominis</a> tendon and the tendon of the <a href="https://brookbushinstitute.com/courses/adductors" target="_blank" rel="noopener">adductor longus</a> may be the most significant link between the trunk muscles and <a href="https://brookbushinstitute.com/courses/adductors" target="_blank" rel="noopener">adductor muscles</a> that comprise the AOS.
 The <a href="https://brookbushinstitute.com/courses/rectus-abdominis-pyramidalis" target="_blank" rel="noopener">rectus abdominis</a> is a strong lumbar flexor, also contributing to <a id="posterior" data-tip="1565" target="_blank" href="/glossary-term/posterior" class="glossary">posterior</a> tilting of the pelvis, and the sacral <a id="counter-nutation" data-tip="1214" target="_blank" href="/glossary-term/counter-nutation" class="glossary">counter-nutation</a> linked to lumbar flexion (13-15). This <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> may be active during <a id="axial-skeleton" data-tip="1292" target="_blank" href="/glossary-term/axial-skeleton" class="glossary">axial</a> rotation and <a id="lateral" data-tip="1567" target="_blank" href="/glossary-term/lateral" class="glossary">lateral</a> stabilization of the spine (16); however, it is doubtful that this recruitment contributes to rotation and/or side-bending force vectors. It is more likely this activity is a co-contraction with the lumbar erectors to aid in bracing (stabilization of) the lumbar spine (17). This bracing function should not be confused with the type of stabilization demonstrated by the <a href="https://brookbushinstitute.com/courses/intrinsic-stabilization-subsystem" target="_blank" rel="noopener">Intrinsic stabilization Subsystem (ISS)</a>, which is anticipatory, <a id="bilateral" data-tip="1552" target="_blank" href="/glossary-term/bilateral" class="glossary">bilateral</a>, non-direction dependent, and noted even during low intensity tasks. Recruitment of the <a href="https://brookbushinstitute.com/courses/rectus-abdominis-pyramidalis" target="_blank" rel="noopener">rectus abdominis</a> is direction <a id="specificity" data-tip="1224" target="_blank" href="/glossary-term/specificity" class="glossary">specific</a> and related to larger loads (18).
 The activity of the <a href="https://brookbushinstitute.com/courses/rectus-abdominis-pyramidalis" target="_blank" rel="noopener">rectus abdominis</a> (as well as the <a href="https://brookbushinstitute.com/courses/external-obliques" target="_blank" rel="noopener">external obliques</a>) relative to low back pain and <a href="https://brookbushinstitute.com/courses/lumbo-pelvic-hip-complex-dysfunction-lphcd" target="_blank" rel="noopener">LPHCD</a> is complex. Swayback <a id="posture" data-tip="1661" target="_blank" href="/glossary-term/posture" class="glossary">postures</a> may result in an increase or decrease in activity (19, 20), low back pain may result in decreased <a href="https://brookbushinstitute.com/courses/rectus-abdominis-pyramidalis" target="_blank" rel="noopener">rectus abdominis</a> activity during rotation (21), but increased reliance when fatigued (22), low back pain patients generally are weaker in trunk flexion than extension (23); however, they recruit the <a href="https://brookbushinstitute.com/courses/rectus-abdominis-pyramidalis" target="_blank" rel="noopener">rectus abdominis</a> more during stair climbing (24), and chronic low back pain patients typically cannot differentiate between transverse abdominis and <a href="https://brookbushinstitute.com/courses/rectus-abdominis-pyramidalis" target="_blank" rel="noopener">rectus abdominis</a> activation during the abdominal <a id="drawing-in" data-tip="1580" target="_blank" href="/glossary-term/drawing-in" class="glossary">drawing-in</a> maneuver (<a id="drawing-in" data-tip="1588" target="_blank" href="/glossary-term/drawing-in" class="glossary">ADIM</a>) (25). This pattern of simultaneously &quot;more and less&quot; may suggest that the <a href="https://brookbushinstitute.com/courses/rectus-abdominis-pyramidalis" target="_blank" rel="noopener">rectus abdominis</a> is compensating for inhibition of primary stabilizers (<a href="https://brookbushinstitute.com/courses/intrinsic-stabilization-subsystem" target="_blank" rel="noopener">ISS</a>); a concept referred to as <a id="synergistic-dominance" data-tip="1643" target="_blank" href="/glossary-term/synergistic-dominance" class="glossary">synergistic dominance</a>. Generally, <a id="synergistic-dominance" data-tip="1647" target="_blank" href="/glossary-term/synergistic-dominance" class="glossary">over-active synergists</a> demonstrate an increase in activity due to inhibition of other primary musculature, but less strength due to an increase in length and disruption of <a id="optimal" data-tip="1571" target="_blank" href="/glossary-term/optimal" class="glossary">optimal</a> <a id="lengthtension-relationship" data-tip="1681" target="_blank" href="/glossary-term/lengthtension-relationship" class="glossary">length/tension relationship</a>.
 Note: The <a href="https://brookbushinstitute.com/courses/rectus-abdominis-pyramidalis" target="_blank" rel="noopener">pyramidalis</a> lies between the right and left <a href="https://brookbushinstitute.com/courses/rectus-abdominis-pyramidalis" target="_blank" rel="noopener">rectus abdominis</a>, within the <a href="https://brookbushinstitute.com/glossary/anterior/" target="_blank" rel="noopener">anterior</a> rectus sheath at the linea alba. Although it is mentioned in this article, it is only mentioned in an attempt to be comprehensive. This <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> does not play a role in intervention selection or practical application, as it only serves to increase <a id="tension" data-tip="1229" target="_blank" href="/glossary-term/tension" class="glossary">tension</a> in the linea alba, and is absent in 17 - 25% of individuals (26).
 <a href="https://brookbush.s3.us-east-2.amazonaws.com/wordpress/wp-content/uploads/2017/05/AOS.jpg" target="_blank" rel="noopener"><img alt="Fascial attachment of the muscles in the anterior oblique subsystem" title="Muscles that attach to the pubis including Fascial Attachment between Rectus Abdominis and Adductor Tendons" src="https://www.datocms-assets.com/25800/1649099601-aos.jpg"> </a>
 Fascial Attachment between Rectus Abdominis and Adductor Tendons
 </div>
</div>

Rectus Abdominis (and Pyramidalis)

<div tabindex="0">
 The <a id="anterior" data-tip="1566" target="_blank" href="/glossary-term/anterior" class="glossary">anterior</a> layer of the abdominal fascia is a continuation of the <a href="https://brookbushinstitute.com/courses/external-obliques" target="_blank" rel="noopener">external oblique</a> fascia, which passes superficial to the <a href="https://brookbushinstitute.com/courses/rectus-abdominis-pyramidalis" target="_blank" rel="noopener">rectus abdominis</a>, and invests in, or is continuous with the fascia from the <a id="contralateral" data-tip="1549" target="_blank" href="/glossary-term/contralateral" class="glossary">contralateral</a> side at the linea alba (27). The <a href="https://brookbushinstitute.com/courses/external-obliques" target="_blank" rel="noopener">external obliques</a> are likely the <a id="prime-mover" data-tip="1663" target="_blank" href="/glossary-term/prime-mover" class="glossary">prime movers</a> for trunk rotation and <a id="lateral" data-tip="1567" target="_blank" href="/glossary-term/lateral" class="glossary">lateral</a> flexion (16, 28-30), and are active during flexion and forceful expiration (30-32). The recruitment of the <a href="https://brookbushinstitute.com/courses/external-obliques" target="_blank" rel="noopener">external obliques </a>varies significantly from the other muscles of the <a id="lateral" data-tip="1567" target="_blank" href="/glossary-term/lateral" class="glossary">lateral</a> abdominal wall. The <a href="https://brookbushinstitute.com/courses/external-obliques" target="_blank" rel="noopener">external obliques</a> contribute to contra-lateral rotation of the spine and do not demonstrate the &quot;bilateral co-activation&quot; often noted in the <a href="https://brookbushinstitute.com/courses/internal-obliques" target="_blank" rel="noopener">internal obliques</a> and transverse abdominis during static or dynamic rotation of the trunk (16, 33). Although the <a href="https://brookbushinstitute.com/courses/external-obliques" target="_blank" rel="noopener">external obliques</a> may also contribute to stabilization, they do so in a direction-dependent manner (ex. unilaterally active during eccentric deceleration of rotation) (34), and in response to larger loads (bracing) (17). Further, the <a href="https://brookbushinstitute.com/courses/external-obliques" target="_blank" rel="noopener">external obliques</a> are also more active during a <a id="posterior" data-tip="1565" target="_blank" href="/glossary-term/posterior" class="glossary">posterior</a> pelvic tilt than during the abdominal <a id="drawing-in" data-tip="1580" target="_blank" href="/glossary-term/drawing-in" class="glossary">drawing-in</a> maneuver (<a id="drawing-in" data-tip="1588" target="_blank" href="/glossary-term/drawing-in" class="glossary">ADIM</a>) (35). In fact, their activity is not necessary to increase intra-abdominal pressure (36), which may be attributed to a lack of attachment to the thoracolumbar fascia (37). In short, the <a href="https://brookbushinstitute.com/courses/external-obliques" target="_blank" rel="noopener">external oblique</a> should likely be categorized as a global mover with the <a href="https://brookbushinstitute.com/courses/rectus-abdominis-pyramidalis" target="_blank" rel="noopener">rectus abdominis</a> and as a <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> the AOS, whereas the <a href="https://brookbushinstitute.com/courses/internal-obliques" target="_blank" rel="noopener">internal obliques</a> and transverse abdominis behave like stabilizers and other muscles of the <a href="https://brookbushinstitute.com/courses/intrinsic-stabilization-subsystem" target="_blank" rel="noopener">Intrinsic stabilization Subsystem (ISS) </a> .
 The behavior of the <a href="https://brookbushinstitute.com/courses/external-obliques" target="_blank" rel="noopener">external obliques</a> relative to LPHCD and low back pain resembles that of the <a href="https://brookbushinstitute.com/courses/rectus-abdominis-pyramidalis" target="_blank" rel="noopener">rectus abdominis</a>; however, the alterations in activity are easier to predict. Studies show that low back pain and fatigue increase reliance on the <a href="https://brookbushinstitute.com/courses/external-obliques" target="_blank" rel="noopener">external obliques</a>, relative to a decrease in <a href="https://brookbushinstitute.com/courses/internal-obliques" target="_blank" rel="noopener">internal obliques</a> and transverse abdominis activity and in some cases <a href="https://brookbushinstitute.com/courses/rectus-abdominis-pyramidalis" target="_blank" rel="noopener">rectus abdominis</a> activity (22 - 25, 38). Like the <a href="https://brookbushinstitute.com/courses/rectus-abdominis-pyramidalis" target="_blank" rel="noopener">rectus abdominis</a>, the <a href="https://brookbushinstitute.com/courses/external-obliques" target="_blank" rel="noopener">external obliques</a> exhibit less activity in sway standing (19), may be more active (bilaterally) to stabilize the spine (bracing) during functional tasks in those with low back pain, and are more active during exercises requiring more <a id="stability" data-tip="1191" target="_blank" href="/glossary-term/stability" class="glossary">stability</a> (ex. <a href="https://brookbushinstitute.com/video/ball-bridge" target="_blank" rel="noopener">bridges on the ball</a>) (19, 39, 40). This behavior implies that in those exhibiting dysfunction, the <a href="https://brookbushinstitute.com/courses/external-obliques" target="_blank" rel="noopener">external obliques</a> become <a id="synergistic-dominance" data-tip="1649" target="_blank" href="/glossary-term/synergistic-dominance" class="glossary">synergistically dominant</a> for an inhibited transverse abdominis and <a href="https://brookbushinstitute.com/courses/internal-obliques" target="_blank" rel="noopener">internal obliques</a>; behavior that is most often attributed to muscles that have adopted maladaptive behavior of long and over-active. This behavior and categorization are the same as the <a href="https://brookbushinstitute.com/courses/rectus-abdominis-pyramidalis" target="_blank" rel="noopener">rectus abdominis</a>.
 <img src="https://www.datocms-assets.com/25800/1650604543-cadaver-abdominal-muscles.jpg" title="The multiple layers of the abdominal fascia including rectus abdominis, external obliques, internal obliques, and transverse abdominis" alt="Layers of the abdominal muscles and fascia">
 <a href="https://brookbush.s3.us-east-2.amazonaws.com/wordpress/wp-content/uploads/2013/07/B9781416067269000043_f004-001ab-9781416067269.jpg" target="_blank" rel="noopener"></a> Layers of abdominal muscles and fascia. - http://clinicalgate.com/anatomy-and-mechanics-of-the-abdominal-muscles/
</div>

 External Obliques

The abdominal fascia runs with some continuity from abdomen, through pubic symphysis, into the tendons of the <a id="anterior" data-tip="1566" target="_blank" href="/glossary-term/anterior" class="glossary">anterior</a> <a href="https://brookbushinstitute.com/courses/adductors" target="_blank" rel="noopener">adductors</a>. The strongest fascial relationship likely exists between the tendons of the <a href="https://brookbushinstitute.com/courses/rectus-abdominis-pyramidalis" target="_blank" rel="noopener">rectus abdominis</a> and the tendons of the <a href="https://brookbushinstitute.com/courses/adductors" target="_blank" rel="noopener">adductor longus muscles</a>. The continuity between the <a href="https://brookbushinstitute.com/courses/rectus-abdominis-pyramidalis" target="_blank" rel="noopener">rectus abdominis</a> and the <a href="https://brookbushinstitute.com/courses/adductors" target="_blank" rel="noopener">adductor longus</a> can then be expanded upon by location to the tendons of the rest of the <a id="anterior" data-tip="1566" target="_blank" href="/glossary-term/anterior" class="glossary">anterior</a> adductors. The tendon of the <a href="https://brookbushinstitute.com/courses/adductors" target="_blank" rel="noopener">pectineus</a> abuts the <a id="lateral" data-tip="1567" target="_blank" href="/glossary-term/lateral" class="glossary">lateral</a> side of the <a href="https://brookbushinstitute.com/courses/rectus-abdominis-pyramidalis" target="_blank" rel="noopener">rectus abdominis</a> tendon, and the attachments of the <a href="https://brookbushinstitute.com/courses/adductors">gracilis and adductor brevis </a>abut the tendon of the <a href="https://brookbushinstitute.com/courses/adductors" target="_blank" rel="noopener">adductor longus</a> inferiorly and laterally.
A few publications <a id="base-of-support" data-tip="1197" target="_blank" href="/glossary-term/base-of-support" class="glossary">support</a> a relationship that includes the sacroiliac joint, pubic symphysis, <a href="https://brookbushinstitute.com/glossary/anterior/" target="_blank" rel="noopener">anterior</a> abdominal activity, and <a href="https://brookbushinstitute.com/courses/adductors" target="_blank" rel="noopener">adductor</a> activity (1, 42-45). The most direct <a id="base-of-support" data-tip="1197" target="_blank" href="/glossary-term/base-of-support" class="glossary">support</a> in the research to date can be found in a study by Snijders et al.. This study demonstrated that crossing the legs decreased the activity of the <a href="https://brookbushinstitute.com/courses/internal-obliques" target="_blank" rel="noopener">internal obliques </a> (45). It is hypothesized that crossing the legs altered adductor activity and force imparted on the pubis, resulting in a reduction in activity by the <a href="https://brookbushinstitute.com/courses/internal-obliques" target="_blank" rel="noopener">internal obliques</a> to equalize force on the pubis. Another study worth mentioning investigated altered <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> activity in individuals exhibiting signs of sacroiliac joint pain. In this study, sacroiliac joint dysfunction was correlated with <a href="https://brookbushinstitute.com/courses/adductors" target="_blank" rel="noopener">adductor</a> activity that remained unchanged (along with <a href="https://brookbushinstitute.com/courses/tensor-fascia-latae-tfl" target="_blank" rel="noopener">TFL</a>, <a href="https://brookbushinstitute.com/courses/biceps-femoris" target="_blank" rel="noopener">biceps femoris</a>), which is a relative increase when compared to <a href="https://brookbushinstitute.com/courses/internal-obliques" target="_blank" rel="noopener">internal oblique</a>, lumbar multifidus, and <a href="https://brookbushinstitute.com/courses/gluteus-maximus" target="_blank" rel="noopener">gluteus maximus</a> activity that decreased or fired later (42). Although these studies are not direct evidence of a myofascial synergy that includes the abdominal fascia, the studies imply a relationship between the muscles and joints that comprise the AOS.
Over-activity of the <a href="https://brookbushinstitute.com/courses/adductors" target="_blank" rel="noopener">adductors</a> has been correlated with <a href="https://brookbushinstitute.com/video/overhead-squat-assessment-6-knees-bow-in-breakdown" target="_blank" rel="noopener">functional knee valgus </a>(46-48), hinting at this <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> groups common maladaptive behavior. As mentioned above, individuals with sacroiliac joint dysfunction demonstrated a relative increase in adductor activity during functional tasks (49). Although it may not be a direct indicator of relative changes in length, the adductors (and adductor tendons) are commonly associated with tendonitis and groin pain (50-52), of these muscles the adductor longus seems to be the most often affected (53). Although more research is needed, current evidence suggests these muscles are commonly over-active, and observations in clinic would suggest that this <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> has a propensity to adaptively shorten and restrict <a id="mobility" data-tip="1455" target="_blank" href="/glossary-term/mobility" class="glossary">mobility</a>.
<a href="https://brookbush.s3.us-east-2.amazonaws.com/wordpress/wp-content/uploads/2016/06/Attachments-on-Pubis.jpg" target="_blank" rel="noopener"><img src="https://www.datocms-assets.com/25800/1650604707-aos-attachment-on-pubis.jpg" title="Muscle Attachments on &lt;a id=" anterior" data-tip="1566" target="_blank" href="/glossary-term/anterior" class="glossary">Anterior</a> Pelvis, Femur and Lumbar Spine - Donald A. Neumann, &#x201C;Kinesiology of the Musculoskeletal System: Foundations of Rehabilitation &#x2013; 2nd Edition&#x201D; &#xA9; 2012 Mosby, Inc.&quot; alt=&quot;The muscles attachments of the <a id="anterior" data-tip="1566" target="_blank" href="/glossary-term/anterior" class="glossary">Anterior</a> oblique subsystem&quot;&gt;Muscle Attachments on <a id="anterior" data-tip="1566" target="_blank" href="/glossary-term/anterior" class="glossary">Anterior</a> Pelvis, Femur and Lumbar Spine - Donald A. Neumann, &#x201C;Kinesiology of the Musculoskeletal System: Foundations of Rehabilitation &#x2013; 2nd Edition&#x201D; &#xA9; 2012 Mosby, Inc.

The most superficial fibers of the sternal head of the <a href="https://brookbushinstitute.com/courses/pectoralis-major" target="_blank" rel="noopener">pectoralis major</a> invest in the fascia of the <a href="https://brookbushinstitute.com/courses/external-obliques" target="_blank" rel="noopener">external obliques</a> and sometimes the <a href="https://brookbushinstitute.com/courses/rectus-abdominis-pyramidalis" target="_blank" rel="noopener">rectus abdominis</a> (4, 54). This inspires consideration of the <a href="https://brookbushinstitute.com/courses/pectoralis-major" target="_blank" rel="noopener">pectoralis major</a> (and <a href="https://brookbushinstitute.com/courses/serratus-anterior" target="_blank" rel="noopener">serratus anterior</a> discussed below) as part of the AOS, and the AOS as the primary synergy responsible for generating force during some of the most powerful activities in sports (e.g. throwing a baseball, swinging a golf club, chop patterns, lineman pushing, etc.).
Research has demonstrated that the <a href="https://brookbushinstitute.com/courses/pectoralis-major" target="_blank" rel="noopener">pectoralis major</a> contributes to horizontal adduction and internal rotation, as well as extension and adduction from an arm elevated position (55-58). This includes activities, such as the tennis forehand and serve, the concentric phases of a golf swing or baseball pitch, swimming, and dumbbell pull-overs (59-64). Several studies have compared <a href="https://brookbushinstitute.com/video/dumbbell-chest-press-and-progressions" target="_blank" rel="noopener">dumbbell press</a>, <a href="https://brookbushinstitute.com/video/bench-press-chest-press" target="_blank" rel="noopener">bench press</a>, and chest flye variations. Incline press, flat, and decline press result in varied recruitment of <a href="https://brookbushinstitute.com/courses/pectoralis-major" target="_blank" rel="noopener">pectoralis major</a> fibers, with lower fibers (sternal head) being recruited more during a decline press; the clavicular head seems to be recruited similarly at all angles (65-67). Flyes resulted in a shorter recruitment period than pressing movements (68). <a id="stability" data-tip="1194" target="_blank" href="/glossary-term/stability" class="glossary">Unstable</a> environments often result in similar recruitment of the <a href="https://brookbushinstitute.com/courses/pectoralis-major" target="_blank" rel="noopener">pectoralis major</a> with less external load; however, most studies do not demonstrate that the addition of <a id="stability" data-tip="1193" target="_blank" href="/glossary-term/stability" class="glossary">instability</a> to an exercise increases <a href="https://brookbushinstitute.com/courses/pectoralis-major" target="_blank" rel="noopener">pectoralis major</a> recruitment (other muscles are often recruited more) (69, 71 -74).
The <a href="https://brookbushinstitute.com/courses/pectoralis-major" target="_blank" rel="noopener">pectoralis major</a> behaves like a prime mover; that is, it is recruited for the concentric phase of large powerful movements, following the recruitment of smaller stabilizers. In a study by David et al. it was demonstrated that the <a href="https://brookbushinstitute.com/courses/pectoralis-major" target="_blank" rel="noopener">pectoralis major</a> fired after recruitment of the rotator cuff muscles and the biceps brachii during internal and external rotation, and in a study by Saeterbakken et al. <a id="stability" data-tip="1193" target="_blank" href="/glossary-term/stability" class="glossary">instability</a> during a chest press did not increase <a href="https://brookbushinstitute.com/courses/pectoralis-major" target="_blank" rel="noopener">pectoralis major</a> activity but did increase biceps brachii activity (75, 76). In a study by Wang et al. the <a href="https://brookbushinstitute.com/courses/pectoralis-major" target="_blank" rel="noopener">pectoralis major</a> was more active during concentric internal rotation than eccentric external rotation, and a study by Kronberg et al. demonstrated that the <a href="https://brookbushinstitute.com/courses/pectoralis-major" target="_blank" rel="noopener">pectoralis major</a> is not active and does not aid in shoulder stabilization during flexion (77, 78). An interesting study by Hirashima et al. demonstrated that overhead throwing followed a <a id="proximal" data-tip="1564" target="_blank" href="/glossary-term/proximal" class="glossary">proximal</a> to <a id="distal" data-tip="1563" target="_blank" href="/glossary-term/distal" class="glossary">distal</a> recruitment pattern; that is, although the rotator cuff and biceps brachii may fire prior to the <a href="https://brookbushinstitute.com/courses/pectoralis-major" target="_blank" rel="noopener">pectoralis major</a>, the <a href="https://brookbushinstitute.com/courses/pectoralis-major" target="_blank" rel="noopener">pectoralis major</a> fires prior to elbow extensors and wrist flexors (79). This study also demonstrated synergy between the <a href="https://brookbushinstitute.com/courses/external-obliques" target="_blank" rel="noopener">external obliques</a>, <a href="https://brookbushinstitute.com/courses/serratus-anterior" target="_blank" rel="noopener">serratus anterior</a>, and <a href="https://brookbushinstitute.com/courses/pectoralis-major" target="_blank" rel="noopener">pectoralis major</a>.
The <a href="https://brookbushinstitute.com/courses/pectoralis-major" target="_blank" rel="noopener">pectoralis major</a> does appear to be one of the few muscles that adopts the maladaptive behavior of short/under-active in those exhibiting dysfunction, supporting the notion of &quot;prime mover inhibition.&quot; In two studies that compared <a href="https://brookbushinstitute.com/courses/pectoralis-major" target="_blank" rel="noopener">pectoralis major</a> activity in those exhibiting signs of shoulder dysfunction, the <a href="https://brookbushinstitute.com/courses/pectoralis-major" target="_blank" rel="noopener">pectoralis major </a>demonstrated less activity (64, 80). However, a study on patients with major rotator cuff tears demonstrated increased <a href="https://brookbushinstitute.com/courses/pectoralis-major" target="_blank" rel="noopener">pectoralis major</a> activity during flexion, and that activity returned to normal when pain decreased following subacromial injection (70). Although these may be viewed as contradictory findings, it may also imply a role reversal from concentric force producer to eccentric <a id="stabilizers" data-tip="1653" target="_blank" href="/glossary-term/stabilizers" class="glossary">stabilizer</a>. Further, this may be normal activity for an inhibited prime mover; more research is needed. Relative to exercise, the <a href="https://brookbushinstitute.com/courses/pectoralis-major" target="_blank" rel="noopener">pectoralis major</a> may exhibit more activity than the <a href="https://brookbushinstitute.com/courses/serratus-anterior" target="_blank" rel="noopener">serratus anterior</a> during pushing motions in those exhibiting scapular winging; however, this activity may be reversed with band resisted abduction during <a href="https://brookbushinstitute.com/courses/serratus-anterior" target="_blank" rel="noopener">serratus anterior</a> exercise (81, 82).

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 The superficial fascia of the <a href="https://brookbushinstitute.com/courses/serratus-anterior" target="_blank" rel="noopener">serratus anterior</a> runs continuous with the fascia of the <a href="https://brookbushinstitute.com/courses/external-obliques" target="_blank" rel="noopener">external obliques</a>, which is continuous with the <a id="anterior" data-tip="1566" target="_blank" href="/glossary-term/anterior" class="glossary">anterior</a> abdominal fascia (1). This fascial relationship may imply that this important <a id="stabilizers" data-tip="1653" target="_blank" href="/glossary-term/stabilizers" class="glossary">stabilizer</a> and mover of the scapula is part of the AOS and that the AOS is a synergy responsible for generating <a id="power" data-tip="1399" target="_blank" href="/glossary-term/power" class="glossary">power</a> in many explosive upper and lower body sporting activities, e.g. throwing a baseball, swinging a golf club, pushing a defender, etc. (as mentioned under &quot;<a href="https://brookbushinstitute.com/courses/pectoralis-major" target="_blank" rel="noopener">Pectoralis Major</a>&quot;). An interesting study by Hirashima et al. demonstrated that overhead throwing followed a <a id="proximal" data-tip="1564" target="_blank" href="/glossary-term/proximal" class="glossary">proximal</a> to <a id="distal" data-tip="1563" target="_blank" href="/glossary-term/distal" class="glossary">distal</a> recruitment pattern that started with <a id="contralateral" data-tip="1549" target="_blank" href="/glossary-term/contralateral" class="glossary">contralateral</a> than <a id="ipsilateral" data-tip="1550" target="_blank" href="/glossary-term/ipsilateral" class="glossary">ipsilateral</a> <a href="https://brookbushinstitute.com/courses/external-obliques" target="_blank" rel="noopener">external obliques</a>, then <a href="https://brookbushinstitute.com/courses/serratus-anterior" target="_blank" rel="noopener">serratus anterior</a>, then <a href="https://brookbushinstitute.com/courses/pectoralis-major" target="_blank" rel="noopener">pectoralis major</a> followed by elbow extensors (79). Additional stabilizing muscles were also recruited, but the sequence demonstrated in this study may be the best example of loading and recruiting the AOS during a functional activity.
 The <a href="https://brookbushinstitute.com/courses/serratus-anterior" target="_blank" rel="noopener">serratus anterior</a> is a protractor, upward rotator, and <a id="posterior" data-tip="1565" target="_blank" href="/glossary-term/posterior" class="glossary">posterior</a> tipper. Studies show that the <a href="https://brookbushinstitute.com/courses/serratus-anterior" target="_blank" rel="noopener">serratus anterior</a> is highly active in the trailing arm of forward swing and throughout back swing during golf (83, 84), works in synchronization with the <a href="https://brookbushinstitute.com/courses/pectoralis-major" target="_blank" rel="noopener">pectoralis major</a> during a windmill style softball pitch (85), and pushing motions that include protraction (86, 87), and works in synchronization with the <a href="https://brookbushinstitute.com/courses/trapezius-muscle" target="_blank" rel="noopener">upper trapezius</a> during the tennis serve (88). These studies suggest that the <a href="https://brookbushinstitute.com/courses/serratus-anterior" target="_blank" rel="noopener">serratus anterior</a> acts like a <a id="prime-mover" data-tip="1662" target="_blank" href="/glossary-term/prime-mover" class="glossary">prime mover</a>, and in conjunction with other <a id="prime-mover" data-tip="1663" target="_blank" href="/glossary-term/prime-mover" class="glossary">prime movers</a>. However, the <a href="https://brookbushinstitute.com/courses/serratus-anterior" target="_blank" rel="noopener">serratus anterior</a> is also highly active during all 3 tennis strokes (89), is active continually during all phases of the freestyle stroke during swimming (90, 91), and is active throughout all upper body PNF patterns (92). This continuous activity, regardless of the direction of motion, suggests a role in scapular stabilization. These findings suggest that the <a href="https://brookbushinstitute.com/courses/serratus-anterior" target="_blank" rel="noopener">serratus anterior</a> likely functions as both <a id="prime-mover" data-tip="1662" target="_blank" href="/glossary-term/prime-mover" class="glossary">prime mover</a> and <a id="stabilizers" data-tip="1653" target="_blank" href="/glossary-term/stabilizers" class="glossary">stabilizer</a> of the scapula (along with the <a href="https://brookbushinstitute.com/courses/trapezius-muscle" target="_blank" rel="noopener">trapezius</a> muscles).
 The <a href="https://brookbushinstitute.com/courses/serratus-anterior" target="_blank" rel="noopener">serratus anterior</a> has a propensity toward under-activity in those exhibiting dysfunction. Several studies demonstrate that <a id="anterior" data-tip="1566" target="_blank" href="/glossary-term/anterior" class="glossary">anterior</a> shoulder pain and/or impingement is correlated with a decrease in <a href="https://brookbushinstitute.com/courses/serratus-anterior" target="_blank" rel="noopener">serratus anterior</a> activity, including altered timing and decoupling from synchronization with the <a href="https://brookbushinstitute.com/courses/trapezius-muscle" target="_blank" rel="noopener">lower trapezius</a> (64, 93-95). A similar decrease is noted in those diagnosed with <a id="anterior" data-tip="1566" target="_blank" href="/glossary-term/anterior" class="glossary">anterior</a> shoulder <a id="stability" data-tip="1193" target="_blank" href="/glossary-term/stability" class="glossary">instability</a> (96, 97). Both cervical dysfunction and forward head <a id="posture" data-tip="1658" target="_blank" href="/glossary-term/posture" class="glossary">posture</a> also decrease <a href="https://brookbushinstitute.com/courses/serratus-anterior" target="_blank" rel="noopener">serratus anterior</a> activity (98 - 102), and even <a id="lateral" data-tip="1567" target="_blank" href="/glossary-term/lateral" class="glossary">lateral</a> epicondylitis has been correlated with scapular <a id="dyskinesis" data-tip="1693" target="_blank" href="/glossary-term/dyskinesis" class="glossary">dyskinesis</a> (103). This propensity toward under-activity may be a precursor to shoulder dysfunction, as two studies demonstrate that a fatiguing shoulder raise protocol results in scapular <a id="dyskinesis" data-tip="1693" target="_blank" href="/glossary-term/dyskinesis" class="glossary">dyskinesis</a> and altered activity (103, 104). Could it be that reinforcement of this &quot;fatigue/compensatory pattern&quot; during repetitive daily tasks, causes a shift toward this pattern over time? The under-activity of the <a href="https://brookbushinstitute.com/courses/serratus-anterior" target="_blank" rel="noopener">serratus anterior</a> is also coupled with an increase in length. Several studies have noted that shoulder dysfunction results in excessive downward rotation, <a id="anterior" data-tip="1566" target="_blank" href="/glossary-term/anterior" class="glossary">anterior</a> tipping, and internal rotation of the scapula, that is, during functional tasks that rely on the elevation of the arm, those exhibiting dysfunction exhibit inadequate upward rotation, <a id="posterior" data-tip="1565" target="_blank" href="/glossary-term/posterior" class="glossary">posterior</a> tipping, and maintenance of the scapula against the ribcage (104 - 109).
 A variety of interventions affecting the <a href="https://brookbushinstitute.com/courses/serratus-anterior" target="_blank" rel="noopener">serratus anterior</a> have been researched. Pressing motions, including pressing with &quot;a plus&quot; (protraction), and pressing that requires more or less <a id="stability" data-tip="1191" target="_blank" href="/glossary-term/stability" class="glossary">stability</a> have been well-researched. The largest issue with pressing motions is that many variations of pushing also increase <a href="https://brookbushinstitute.com/courses/trapezius-muscle" target="_blank" rel="noopener">upper trapezius</a> and <a href="https://brookbushinstitute.com/courses/pectoralis-minor" target="_blank" rel="noopener">pectoralis minor</a> activity which may reinforce compensatory patterns discussed above. Wall <a href="https://brookbushinstitute.com/video/push-ups-and-progression" target="_blank" rel="noopener">push-ups</a>, push-ups with a plus, and feet-up push-ups significantly increase <a href="https://brookbushinstitute.com/courses/trapezius-muscle" target="_blank" rel="noopener">upper trapezius</a> activity, and punch-ups increase <a href="https://brookbushinstitute.com/courses/pectoralis-minor" target="_blank" rel="noopener">pectoralis minor</a> activity (110 - 113). <a id="stability" data-tip="1194" target="_blank" href="/glossary-term/stability" class="glossary">Unstable</a> pushing motions may be effective for a variety of goals; however, it is unlikely that <a id="stability" data-tip="1191" target="_blank" href="/glossary-term/stability" class="glossary">stability</a> <a id="exercise-progression" data-tip="1182" target="_blank" href="/glossary-term/exercise-progression" class="glossary">progressions</a> will result in a relative increase in <a href="https://brookbushinstitute.com/courses/serratus-anterior" target="_blank" rel="noopener">serratus anterior</a> activity. Bench press actually had a better ratio of the <a href="https://brookbushinstitute.com/courses/serratus-anterior" target="_blank" rel="noopener">serratus anterior</a> to <a href="https://brookbushinstitute.com/courses/trapezius-muscle" target="_blank" rel="noopener">upper trapezius</a> activity than stable and <a id="stability" data-tip="1194" target="_blank" href="/glossary-term/stability" class="glossary">Unstable</a> <a href="https://brookbushinstitute.com/video/push-ups-and-progression" target="_blank" rel="noopener">push-ups</a> variations (114). Two studies comparing push-ups to <a href="https://brookbushinstitute.com/video/stability-ball-push" target="_blank" rel="noopener">push-ups on a </a><a id="stability" data-tip="1191" target="_blank" href="/glossary-term/stability" class="glossary">stability</a> ball showed no increase in EMG activity (115, 116), and bench press was shown to increase <a href="https://brookbushinstitute.com/courses/serratus-anterior" target="_blank" rel="noopener">serratus anterior</a> activity better than either variation (114). Additionally, those exhibiting scapular <a id="dyskinesis" data-tip="1693" target="_blank" href="/glossary-term/dyskinesis" class="glossary">dyskinesis</a> had less <a href="https://brookbushinstitute.com/courses/serratus-anterior" target="_blank" rel="noopener">serratus anterior</a> activity and more <a href="https://brookbushinstitute.com/courses/trapezius-muscle" target="_blank" rel="noopener">upper trapezius</a> and <a href="https://brookbushinstitute.com/courses/pectoralis-major" target="_blank" rel="noopener">pectoralis major </a>activity during pushing, even when a <a id="stability" data-tip="1191" target="_blank" href="/glossary-term/stability" class="glossary">stability</a> ball was added to <a href="https://brookbushinstitute.com/video/push-ups-and-progression" target="_blank" rel="noopener">push-ups</a> (81, 119). The <a id="hypothesis" data-tip="1446" target="_blank" href="/glossary-term/hypothesis" class="glossary">hypothesis</a> that <a id="stability-training" data-tip="1172" target="_blank" href="/glossary-term/stability-training" class="glossary">stability training</a> would preferentially recruit the <a href="https://brookbushinstitute.com/courses/serratus-anterior" target="_blank" rel="noopener">serratus anterior</a> is likely flawed because it does not consider how other muscles may participate in the stabilization of the shoulder girdle; however, this does not diminish the use of <a id="stability-training" data-tip="1172" target="_blank" href="/glossary-term/stability-training" class="glossary">stability training</a>. Studies have demonstrated that <a id="stability" data-tip="1193" target="_blank" href="/glossary-term/stability" class="glossary">instability</a> increases the activity of other musculature including the <a href="https://brookbushinstitute.com/courses/deltoids" target="_blank" rel="noopener">anterior deltoid</a>, <a href="https://brookbushinstitute.com/courses/pectoralis-major" target="_blank" rel="noopener">pectoralis major</a>, <a href="https://brookbushinstitute.com/courses/trapezius-muscle" target="_blank" rel="noopener">trapezius</a>, and core musculature (69, 71, 114, 116). The increase in activity of multiple muscles may aid in enhancing inter-muscular coordination, and <a id="integration" data-tip="1472" target="_blank" href="/glossary-term/integration" class="glossary">integration</a> of the AOS, once relative activity has been addressed with <a id="release" data-tip="1249" target="_blank" href="/glossary-term/release" class="glossary">release</a> and <a id="activation-technique" data-tip="1531" target="_blank" href="/glossary-term/activation-technique" class="glossary">activation techniques</a>. Interesting note, although <a id="stability" data-tip="1194" target="_blank" href="/glossary-term/stability" class="glossary">Unstable</a> environments do not consistently increase <a href="https://brookbushinstitute.com/courses/serratus-anterior" target="_blank" rel="noopener">serratus anterior</a> EMG, oscillations/vibration training does (117, 118). More systematic experimentation and research is needed to develop easy ways to implement vibration training.
 An alternative technique to pressing is <a href="https://brookbushinstitute.com/video/shoulder-scaption" target="_blank" rel="noopener">scaption</a> (elevation/abduction in the scapular plane). Several studies comparing various &quot;rehabilitation exercises&quot; and motions of the arm showed <a href="https://brookbushinstitute.com/video/shoulder-scaption" target="_blank" rel="noopener">scaption</a> to create the highest <a href="https://brookbushinstitute.com/courses/serratus-anterior" target="_blank" rel="noopener">serratus anterior</a> EMG activity (120-128). Further, unlike pressing motions that also increase activity of commonly over-active muscles (<a href="https://brookbushinstitute.com/courses/trapezius-muscle" target="_blank" rel="noopener">upper trapezius</a> and <a href="https://brookbushinstitute.com/courses/pectoralis-minor" target="_blank" rel="noopener">pectoralis minor</a>), <a href="https://brookbushinstitute.com/video/shoulder-scaption" target="_blank" rel="noopener">scaption</a> pairs the <a href="https://brookbushinstitute.com/courses/serratus-anterior" target="_blank" rel="noopener">serratus anterior</a> with the commonly under-active <a href="https://brookbushinstitute.com/courses/trapezius-muscle" target="_blank" rel="noopener">lower trapezius</a> (120-126). <a href="https://brookbushinstitute.com/video/shoulder-scaption" target="_blank" rel="noopener">Scaption</a> should likely be performed through the largest available range (without compensation or pain), as exercise that results in the most upward rotation resulted in the largest increase in <a href="https://brookbushinstitute.com/courses/serratus-anterior" target="_blank" rel="noopener">serratus anterior</a> activity (128). Additional variations including <a href="https://brookbushinstitute.com/video/nasm-prone-ball-combo-trapezius-activation" target="_blank" rel="noopener">prone scaption</a>, <a href="https://brookbushinstitute.com/video/transverse-abdominis-tva-isolated-activation-quadruped" target="_blank" rel="noopener">scaption in quadruped position</a>, and <a href="https://brookbushinstitute.com/video/serratus-anterior-activation-progressions" target="_blank" rel="noopener">wall slides</a> may also be beneficial, but consideration should be given to patient ability and recruitment of additional musculature (123-124).
 As mentioned above, those exhibiting scapular <a id="dyskinesis" data-tip="1693" target="_blank" href="/glossary-term/dyskinesis" class="glossary">dyskinesis</a> had less <a href="https://brookbushinstitute.com/courses/serratus-anterior" target="_blank" rel="noopener">serratus anterior</a> activity and more <a href="https://brookbushinstitute.com/courses/trapezius-muscle" target="_blank" rel="noopener">upper trapezius</a> and <a href="https://brookbushinstitute.com/courses/pectoralis-major" target="_blank" rel="noopener">pectoralis major</a> activity during pushing type exercise (81, 119). Further, a study by Lucas et al. demonstrated that addressing <a id="latent-trigger-point" data-tip="1133" target="_blank" href="/glossary-term/latent-trigger-point" class="glossary">latent trigger points</a> in muscles of the scapula, aided in normalizing <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> recruitment patterns, including increased <a href="https://brookbushinstitute.com/courses/serratus-anterior" target="_blank" rel="noopener">serratus anterior</a> activity (129). This may imply that <a id="release" data-tip="1249" target="_blank" href="/glossary-term/release" class="glossary">release</a> techniques for typically over-active muscles, and targeted intervention for the <a href="https://brookbushinstitute.com/courses/serratus-anterior" target="_blank" rel="noopener">serratus anterior</a> should precede multi-joint movement patterns.
 <img title="The attachments of the serratus anterior on the ribcage and scapula" src="https://www.datocms-assets.com/25800/1647364629-1642024352-serratus.jpeg" alt="The serratus anterior muscle">
 </div>
</div>

<ul>
 <li>A distinction can be made between <a id="anterior" data-tip="1566" target="_blank" href="/glossary-term/anterior" class="glossary">anterior</a> and <a id="posterior" data-tip="1565" target="_blank" href="/glossary-term/posterior" class="glossary">posterior</a> layers of abdominal fascia and the muscles that invest in those layers.</li>
 <li>The <a id="anterior" data-tip="1566" target="_blank" href="/glossary-term/anterior" class="glossary">anterior</a> layer of the abdominal and oblique fascia is invested by the rectus abdominis and pyramidalis, external obliques, pectoralis major, serratus <a id="anterior" data-tip="1566" target="_blank" href="/glossary-term/anterior" class="glossary">anterior</a>, and <a id="anterior" data-tip="1566" target="_blank" href="/glossary-term/anterior" class="glossary">anterior</a> adductors.</li>
 <li>Any change in <a id="anterior" data-tip="1566" target="_blank" href="/glossary-term/anterior" class="glossary">anterior</a> trunk <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> activity results in a change in the activity of all trunk muscles and an increase in <a id="tension" data-tip="1229" target="_blank" href="/glossary-term/tension" class="glossary">tension</a> in fascial layers.</li>
 <li>Force imparted by any trunk <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> will be transmitted between all layers of the abdominal fascial network.</li>
 <li>The rectus abdominis may play a role in tensing the abdominal fascia and its tendon may have fascial continuity with the adductor longus.</li>
 <li>The rectus abdominis and external obliques behave like a global mover of the spine</li>
 <li>In those exhibiting dysfunction, the rectus abdominis and external obliques behave like <a id="synergistic-dominance" data-tip="1647" target="_blank" href="/glossary-term/synergistic-dominance" class="glossary">over-active synergists</a> (long-over/active).</li>
 <li>Research suggests there may be a relationship between the adductors and <a id="anterior" data-tip="1566" target="_blank" href="/glossary-term/anterior" class="glossary">anterior</a> trunk muscles.</li>
 <li>The adductors have a propensity to become short and over-active.</li>
 <li>Superficial fibers of the pectoralis major and the serratus <a id="anterior" data-tip="1566" target="_blank" href="/glossary-term/anterior" class="glossary">anterior</a> invest in the fascia of the external obliques and sometimes the rectus abdominis.</li>
 <li>The pectoralis major has a propensity toward <a id="prime-mover" data-tip="1662" target="_blank" href="/glossary-term/prime-mover" class="glossary">prime mover</a> inhibition, that is, becoming short/under-active in those exhibiting dysfunction.</li>
 <li>The serratus <a id="anterior" data-tip="1566" target="_blank" href="/glossary-term/anterior" class="glossary">anterior</a> has a propensity to become long/under-active and may benefit from targeted intervention prior to multi-joint patterns.</li>
 <li>The pectoralis major and serratus <a id="anterior" data-tip="1566" target="_blank" href="/glossary-term/anterior" class="glossary">anterior</a> work in synergy during pushing and increasing <a id="stability" data-tip="1193" target="_blank" href="/glossary-term/stability" class="glossary">instability</a> may increase core recruitment (AOS recruitment)</li>
</ul>

<h3> Primary stabilizer of anterior kinetic chain during high-intensity activity: </h3>
Research implies a relationship that includes the sacroiliac joint, pubic symphysis, <a href="https://brookbushinstitute.com/glossary/anterior/" target="_blank" rel="noopener">anterior</a> abdominal activity, and <a href="https://brookbushinstitute.com/courses/adductors" target="_blank" rel="noopener">adductor</a> activity (1, 42-45). The most direct <a id="base-of-support" data-tip="1197" target="_blank" href="/glossary-term/base-of-support" class="glossary">support</a> of this relationship is a study by Snijders et al. demonstrating that crossing the legs decreases the activity of the <a href="https://brookbushinstitute.com/courses/internal-obliques" target="_blank" rel="noopener">internal obliques</a>(45). Another study by Hungerford et al. demonstrated sacroiliac joint dysfunction resulted in a relative increase in <a href="https://brookbushinstitute.com/courses/adductors" target="_blank" rel="noopener">adductor</a>, <a href="https://brookbushinstitute.com/courses/tensor-fascia-latae-tfl" target="_blank" rel="noopener">TFL</a>, <a href="https://brookbushinstitute.com/courses/biceps-femoris" target="_blank" rel="noopener">biceps femoris </a>activity compared to <a href="https://brookbushinstitute.com/courses/internal-obliques" target="_blank" rel="noopener">internal oblique</a>, lumbar multifidus, and <a href="https://brookbushinstitute.com/courses/gluteus-maximus" target="_blank" rel="noopener">gluteus maximus</a> activity that decreased or fired later (42). Although this research does not directly investigate the role of the AOS in the stabilization of the pelvis and lumbar spine, it implies a relationship between the structures involved that may be explained by its role as a <a id="stabilizers" data-tip="1653" target="_blank" href="/glossary-term/stabilizers" class="glossary">stabilizer</a>.
It may be hypothesized that the AOS is the <a id="antagonists" data-tip="1705" target="_blank" href="/glossary-term/antagonists" class="glossary">antagonist</a> to the <a href="https://brookbushinstitute.com/courses/posterior-oblique-subsystem-pos" target="_blank" rel="noopener">Posterior Oblique Subsystem (POS)</a>. That is, the AOS aids in bracing and control of the pubic symphysis, pelvis, and lumbar spine from the front, and the <a href="https://brookbushinstitute.com/courses/posterior-oblique-subsystem-pos" target="_blank" rel="noopener">POS</a> aids in bracing and control of the SIJ, pelvis, and lumbar spine from the back. Note, the term &quot;bracing&quot; is used rather than stabilization, as the AOS and POS are recruited during higher intensity activities to &quot;brace&quot; the lumbar spine. &quot;Drawing in&quot; and <a href="https://brookbushinstitute.com/courses/intrinsic-stabilization-subsystem" target="_blank" rel="noopener">Intrinsic Stabilization Subsystem (ISS)</a> recruitment should be sufficient for low-level activities, and should be synergistic with the AOS and POS during higher intensity activities. This is as analogous to the &quot;size principle&quot; of <a id="motor-unit" data-tip="1303" target="_blank" href="/glossary-term/motor-unit" class="glossary">motor unit</a> recruitment. When load is greater than the capacity of the ISS, the AOS and POS are generally recruited in a direction-specific manner to resist additional load. Several studies have demonstrated that the <a href="https://brookbushinstitute.com/courses/rectus-abdominis-pyramidalis" target="_blank" rel="noopener">rectus abdominis</a> and <a href="https://brookbushinstitute.com/courses/external-obliques" target="_blank" rel="noopener">external obliques</a> are recruited more in those with low back pain (guarding and <a href="https://brookbushinstitute.com/courses/intrinsic-stabilization-subsystem" target="_blank" rel="noopener">ISS </a> impairment), and during higher intensity activity (17, 19, 22, 24, 25, 34, 39, 40).
<h3> Primary eccentric decelerator during high-intensity activity: </h3>
The AOS may play an important &quot;protective&quot; role, as this subsystem can decelerate rotation and extension of the lumbar and thoracic spine. Further, the AOS is involved in eccentric deceleration of an <a id="anterior" data-tip="1566" target="_blank" href="/glossary-term/anterior" class="glossary">anterior</a> pelvic tilt, especially during standing and pushing motions (133-135). Lumbar extension, rotation, and an <a id="anterior" data-tip="1566" target="_blank" href="/glossary-term/anterior" class="glossary">anterior</a> pelvic tilt, have been hypothesized to lead to facet joint and <a id="posterior" data-tip="1565" target="_blank" href="/glossary-term/posterior" class="glossary">posterior</a> disk <a id="compression" data-tip="1595" target="_blank" href="/glossary-term/compression" class="glossary">compression</a>, and have been correlated with low back pain (130-132).
The ability to contribute to eccentric deceleration of shoulder elevation and external rotation, scapular retraction, spine rotation and extension, and hip extension make the AOS the subsystem &quot;loaded&quot; during the &quot;loading phase&quot; of a throw or swing. This may be the best example of loading a myofascial synergy for recoil and <a id="optimal" data-tip="1571" target="_blank" href="/glossary-term/optimal" class="glossary">optimal</a> <a id="power" data-tip="1399" target="_blank" href="/glossary-term/power" class="glossary">power</a> production.
<h3> Throwing, serving, and pushing with power: </h3>
The study by Hirashima et al. (mentioned above) demonstrated <a id="proximal" data-tip="1564" target="_blank" href="/glossary-term/proximal" class="glossary">proximal</a> to <a id="distal" data-tip="1563" target="_blank" href="/glossary-term/distal" class="glossary">distal</a> recruitment of the AOS during overhead throwing; that is, <a id="contralateral" data-tip="1549" target="_blank" href="/glossary-term/contralateral" class="glossary">contralateral</a> than <a id="ipsilateral" data-tip="1550" target="_blank" href="/glossary-term/ipsilateral" class="glossary">ipsilateral</a> <a href="https://brookbushinstitute.com/courses/external-obliques" target="_blank" rel="noopener">external obliques</a>, followed by <a href="https://brookbushinstitute.com/courses/serratus-anterior" target="_blank" rel="noopener">serratus anterior</a>, then shoulder stabilizers, and finally <a href="https://brookbushinstitute.com/courses/pectoralis-major" target="_blank" rel="noopener">pectoralis major</a> and elbow extensors (79). Further, the joint actions described during this motion are a return from the eccentric function of the AOS described above. The majority of this pattern may also be seen during pushing a defender, a tennis serve, a volleyball spike, and the butterfly stroke in swimming. The concentric function of this subsystem may imply it is one of the most important to sports performance.
<h3> Compensations and models of postural dysfunction: </h3>
The AOS could be viewed as a system <a id="prone" data-tip="1561" target="_blank" href="/glossary-term/prone" class="glossary">prone</a> to <a id="synergistic-dominance" data-tip="1643" target="_blank" href="/glossary-term/synergistic-dominance" class="glossary">synergistic dominance</a>. In the Brookbush Institute&apos;s predictive <a id="model" data-tip="1471" target="_blank" href="/glossary-term/model" class="glossary">models</a> of <a href="https://brookbushinstitute.com/courses/upper-body-dysfunction-ubd" target="_blank" rel="noopener">Upper Body Dysfunction (UBD)</a>, <a href="https://brookbushinstitute.com/courses/lumbo-pelvic-hip-complex-dysfunction-lphcd" target="_blank" rel="noopener">Lumbo Pelvic Hip Complex Dysfunction (LPHCD)</a>, Sacroiliac Joint Dysfunction (SIJD), and <a href="https://brookbushinstitute.com/courses/lower-leg-dysfunction" target="_blank" rel="noopener">Lower Extremity dysfunction (LED)</a> this sub-system is over-active and long. Commonly, the over-activity is paired with under-activity of the <a href="https://brookbushinstitute.com/courses/posterior-oblique-subsystem-pos" target="_blank" rel="noopener">Posterior Oblique Subsystem (POS)</a> and may be compensatory for under-activity of the <a href="https://brookbushinstitute.com/courses/intrinsic-stabilization-subsystem" target="_blank" rel="noopener">Intrinsic Stabilization Subsystem (ISS)</a>. Evidence of AOS dominance may result in <a href="https://brookbushinstitute.com/video/overhead-squat-assessment-6-knees-bow-in-breakdown" target="_blank" rel="noopener">knees bow-in</a>, <a href="https://brookbushinstitute.com/video/overhead-squat-assessment-8-excessive-forward-lean" target="_blank" rel="noopener">excessive forward lean</a> or <a href="https://brookbushinstitute.com/video/overhead-squat-assessment-10-arms-fall" target="_blank" rel="noopener">arms fall</a> during an <a href="https://brookbushinstitute.com/courses/solutions-table-overhead-squat-assessment" target="_blank" rel="noopener">Overhead Squat Assessment</a>, and/or an excessive kyphosis, spinal flexion, or an <a href="https://brookbushinstitute.com/video/overhead-squat-assessment-8-excessive-forward-lean" target="_blank" rel="noopener">excessive forward lean</a> during an <a href="https://brookbushinstitute.com/courses/sign-clusters-compensation-patterns-overhead-squat-assessment" target="_blank" rel="noopener">Overhead Squat </a><a id="assessment" data-tip="1478" target="_blank" href="/glossary-term/assessment" class="glossary">Assessment</a> with Modification. Dominance of the <a href="https://brookbushinstitute.com/courses/anterior-oblique-subsystem-aos" target="_blank" rel="noopener"> AOS</a> (and under-activity of the <a href="https://brookbushinstitute.com/courses/posterior-oblique-subsystem-pos" target="_blank" rel="noopener">POS)</a> is generally most dramatic in those individuals exhibiting <a href="https://brookbushinstitute.com/courses/upper-body-dysfunction-ubd" target="_blank" rel="noopener">UBD</a> and <a href="https://brookbushinstitute.com/courses/lower-leg-dysfunction" target="_blank" rel="noopener">LED</a>.
<a href="https://brookbush.s3.us-east-2.amazonaws.com/wordpress/wp-content/uploads/2017/10/stability-ball-push-up-progressi.jpg" target="_blank" rel="noopener"><img alt="A &lt;a id=" stability" data-tip="1191" target="_blank" href="/glossary-term/stability" class="glossary">Stability</a> ball pushup&quot; title=&quot;Dr. Brookbush instructs how to regress a <a id="stability" data-tip="1191" target="_blank" href="/glossary-term/stability" class="glossary">Stability</a> ball push-up.&quot; src=&quot;https://www.datocms-assets.com/25800/1632852857-stability-ball-push-up-progressi.jpg&quot;&gt; <a id="stability" data-tip="1191" target="_blank" href="/glossary-term/stability" class="glossary">Stability</a> Ball Push-up

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 <h3 tabindex="0">Movement Impairment</h3>
 Based on available research on individual muscles, the Brookbush Institute&apos;s (BI&apos;s) predictive <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, and observations in practice, this subsystem is categorized as &quot;long/over-active&quot;. As subsystems are synergies, dynamic multi-segmental <a id="posture" data-tip="1659" target="_blank" href="/glossary-term/posture" class="glossary">postural</a> <a id="assessment" data-tip="1478" target="_blank" href="/glossary-term/assessment" class="glossary">assessment</a> is recommended for determining compensatory activity, strengthening/activation of individual muscles within the system is avoided, but <a id="integration" data-tip="1473" target="_blank" href="/glossary-term/integration" class="glossary">integrated</a> exercise may be appropriate. The BI uses the research and theory of subsystems as a means of refining core and <a id="integration" data-tip="1473" target="_blank" href="/glossary-term/integration" class="glossary">integrated</a> exercise selection. Note, the BI&apos;s Corrective-Template addresses individual structures prior to addressing subsystems to reduce <a id="relative-flexibility" data-tip="1654" target="_blank" href="/glossary-term/relative-flexibility" class="glossary">relative flexibility</a>, <a id="synergistic-dominance" data-tip="1643" target="_blank" href="/glossary-term/synergistic-dominance" class="glossary">synergistic dominance</a>, and compensatory patterns.
 <h3>Assessment: </h3>
 Signs of <a href="https://brookbushinstitute.com/courses/posterior-oblique-subsystem-pos" target="_blank" rel="noopener">AOS</a> over-activity is based on the research, concentric function, and motor behavior described above, and signs are considered relative to the BI&apos;s preferred dynamic <a id="posture" data-tip="1659" target="_blank" href="/glossary-term/posture" class="glossary">postural</a> <a id="assessment" data-tip="1478" target="_blank" href="/glossary-term/assessment" class="glossary">assessment</a>, the <a href="https://brookbushinstitute.com/courses/introduction-overhead-squat-assessment" target="_blank" rel="noopener">Overhead Squat </a><a id="assessment" data-tip="1478" target="_blank" href="/glossary-term/assessment" class="glossary">assessment</a> (OHSA). Specifically, t<span style="display: inline !important; float: none; background-color: transparent; color: #333333; cursor: text; font-family: Georgia,&apos;Times New Roman&apos;,&apos;Bitstream Charter&apos;,Times,serif; font-size: 16px; font-style: normal; font-variant: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: left; text-decoration: none; text-indent: 0px; text-transform: none; -webkit-text-stroke-width: 0px; white-space: normal; word-spacing: 0px;">he AOS <span style="display: inline !important; float: none; background-color: transparent; color: #333333; cursor: text; font-family: Georgia,&apos;Times New Roman&apos;,&apos;Bitstream Charter&apos;,Times,serif; font-size: 16px; font-style: normal; font-variant: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: left; text-decoration: none; text-indent: 0px; text-transform: none; -webkit-text-stroke-width: 0px; white-space: normal; word-spacing: 0px;">contributes concentrically to multi-segmental flexion, as well as hip flexion, adduction, and internal rotation implying <a href="https://brookbushinstitute.com/video/overhead-squat-assessment-8-excessive-forward-lean" target="_blank" rel="noopener noreferrer">excessive forward lean</a> and <a href="https://brookbushinstitute.com/video/overhead-squat-assessment-6-knees-bow-in-breakdown" target="_blank" rel="noopener noreferrer">knees bow in</a> are signs of over-activity. Because of the role the AOS plays in core <a id="stability" data-tip="1191" target="_blank" href="/glossary-term/stability" class="glossary">stability</a> and motion an <a href="https://brookbushinstitute.com/video/overhead-squat-assessment-9-anterior-pelvic-tilt-excessive-lordosis" target="_blank" rel="noopener">excessive lordosis</a><span style="display: inline !important; float: none; background-color: transparent; color: #333333; cursor: text; font-family: Georgia,&apos;Times New Roman&apos;,&apos;Bitstream Charter&apos;,Times,serif; font-size: 16px; font-style: normal; font-variant: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: left; text-decoration: none; text-indent: 0px; text-transform: none; -webkit-text-stroke-width: 0px; white-space: normal; word-spacing: 0px;"> (<a id="anterior" data-tip="1566" target="_blank" href="/glossary-term/anterior" class="glossary">anterior</a> pelvic tilt) is a sign of dysfunction; however, this is a sign of increased length that may be addressed with <a id="integration" data-tip="1473" target="_blank" href="/glossary-term/integration" class="glossary">integrated</a> strengthening exercise<span style="display: inline !important; float: none; background-color: transparent; color: #333333; cursor: text; font-family: Georgia,&apos;Times New Roman&apos;,&apos;Bitstream Charter&apos;,Times,serif; font-size: 16px; font-style: normal; font-variant: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: left; text-decoration: none; text-indent: 0px; text-transform: none; -webkit-text-stroke-width: 0px; white-space: normal; word-spacing: 0px;">. The inclusion of the commonly under-active <a href="https://brookbushinstitute.com/courses/pectoralis-major" target="_blank" rel="noopener">pectoralis major</a> and <a href="https://brookbushinstitute.com/courses/serratus-anterior" target="_blank" rel="noopener">serratus anterior</a> implies that AOS dysfunction may also contribute to the signs of <a href="https://brookbushinstitute.com/video/overhead-squat-assessment-11-shoulders-elevate" target="_blank" rel="noopener" style="background-color: transparent;">shoulders elevate</a> and <a href="https://brookbushinstitute.com/video/overhead-squat-assessment-10-arms-fall" target="_blank" rel="noopener">arms fall</a>. The role of the AOS in <a href="https://brookbushinstitute.com/courses/upper-body-dysfunction-ubd" target="_blank" rel="noopener">Upper Body Dysfunction (UBD)</a> is complex, leading to a peculiar sign during the <a href="https://brookbushinstitute.com/courses/sign-clusters-compensation-patterns-overhead-squat-assessment" target="_blank" rel="noopener">Overhead Squat </a><a id="assessment" data-tip="1478" target="_blank" href="/glossary-term/assessment" class="glossary">assessment</a> with Modification. When the hands are placed on the hips (arms down), the lack of <a id="base-of-support" data-tip="1197" target="_blank" href="/glossary-term/base-of-support" class="glossary">support</a> from a lengthened <a href="https://brookbushinstitute.com/courses/posterior-oblique-subsystem-pos" target="_blank" rel="noopener">POS</a> exaggerates AOS dominance, leading to an excessive kyphosis, spinal flexion, or an <a href="https://brookbushinstitute.com/video/overhead-squat-assessment-8-excessive-forward-lean" target="_blank" rel="noopener">excessive forward lean</a> during re-assessment. Although the exaggerated forward lean looks like <a href="https://brookbushinstitute.com/courses/lumbo-pelvic-hip-complex-dysfunction-lphcd" target="_blank" rel="noopener">Lumbo Pelvic Hip Complex Dysfunction (LPHCD)</a>, practice would suggest it is a sign of <a href="https://brookbushinstitute.com/courses/upper-body-dysfunction-ubd" target="_blank" rel="noopener">UBD</a>. In summary, the signs <a href="https://brookbushinstitute.com/video/overhead-squat-assessment-6-knees-bow-in-breakdown" target="_blank" rel="noopener noreferrer" style="background-color: transparent;">knees bow in</a>, <a href="https://brookbushinstitute.com/video/overhead-squat-assessment-8-excessive-forward-lean" target="_blank" rel="noopener noreferrer" style="background-color: transparent;">excessive forward lean</a>, <a href="https://brookbushinstitute.com/video/overhead-squat-assessment-9-anterior-pelvic-tilt-excessive-lordosis" target="_blank" rel="noopener" style="background-color: transparent;">excessive lordosis</a>, <a href="https://brookbushinstitute.com/video/overhead-squat-assessment-11-shoulders-elevate" target="_blank" rel="noopener" style="background-color: transparent;">shoulders elevate</a>, <a href="https://brookbushinstitute.com/video/overhead-squat-assessment-10-arms-fall" target="_blank" rel="noopener">arms fall</a>, and <a href="https://brookbushinstitute.com/article/overhead-squat-assessment-part-2-sign-clusters-compensation-patterns" target="_blank" rel="noopener">Forward Lean during an Overhead Squat </a><a id="assessment" data-tip="1478" target="_blank" href="/glossary-term/assessment" class="glossary">assessment</a> with Modification may imply AOS over-activity.
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 <h3 tabindex="0">Core Exercise:</h3>
 <div tabindex="0">As mentioned above, the <a title="External Obliques" href="https://brookbushinstitute.com/courses/external-obliques" target="_blank" rel="noopener">external obliques</a> and <a title="Rectus Abdominis" href="https://brookbushinstitute.com/courses/rectus-abdominis-pyramidalis" target="_blank" rel="noopener">rectus abdominis</a> have a propensity to become over-active but are long in those exhibiting signs of <a href="https://brookbushinstitute.com/courses/lumbo-pelvic-hip-complex-dysfunction-lphcd" target="_blank" rel="noopener">LPHCD</a>. The attributes long/over-active are often a sign of synergistic dominance; it is recommended that muscles in this category are addressed by reducing postural dysfunction to optimize length/tension. Research supports this recommendation - in several studies, <a href="https://brookbushinstitute.com/courses/bridge-progression" target="_blank" rel="noopener">bridges</a>, and exercises that focused on posterior tilting immediately improved trunk flexor strength and improved recruitment patterns during gait (139-143). Due to the categorization of long/over-active and these research findings the BI recommends avoiding specific strengthening exercises for the <a title="External Obliques" href="https://brookbushinstitute.com/courses/external-obliques" target="_blank" rel="noopener">external obliques</a> and <a title="Rectus Abdominis" href="https://brookbushinstitute.com/courses/rectus-abdominis-pyramidalis" target="_blank" rel="noopener">rectus abdominis</a> while dysfunction persists. Instead, focus on <a href="https://brookbushinstitute.com/courses/bridge-progression" target="_blank" rel="noopener">bridges</a>, and chop progressions which may aid in improving posture, optimizing length/tension and improving synergy between the AOS and <a href="https://brookbushinstitute.com/courses/posterior-oblique-subsystem-pos" target="_blank" rel="noopener">POS</a>. </div>
 <h3 tabindex="0">Integrated Exercise:</h3>
 <div tabindex="0">The BI suggests ending <span style="display: inline !important; float: none; background-color: transparent; color: #333333; cursor: text; font-family: Georgia,&apos;Times New Roman&apos;,&apos;Bitstream Charter&apos;,Times,serif; font-size: 16px; font-style: normal; font-variant: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: left; text-decoration: none; text-indent: 0px; text-transform: none; -webkit-text-stroke-width: 0px; white-space: normal; word-spacing: 0px;">sessions with multi-joint exercise/activities (integrated exercise) to reinforce new motor patterns. The BI refines &quot;integrated exercise&quot; selection with research and theory on subsystems. As mentioned above, over-activity of the <a href="https://brookbushinstitute.com/courses/adductors" target="_blank" rel="noopener">adductors</a> has been correlated with <a href="https://brookbushinstitute.com/video/overhead-squat-assessment-6-knees-bow-in-breakdown" target="_blank" rel="noopener noreferrer">knees bow in</a> (62-63, 66). Further, it may be implied by function and research that the <a title="External Obliques" href="https://brookbushinstitute.com/courses/external-obliques" target="_blank" rel="noopener">external obliques</a> and <a title="Rectus Abdominis" href="https://brookbushinstitute.com/courses/rectus-abdominis-pyramidalis" target="_blank" rel="noopener">rectus abdominis</a> are over-active in those exhibiting dysfunction (19, 22, 24, 25, 38 - 40), contributing to an <a href="https://brookbushinstitute.com/video/overhead-squat-assessment-8-excessive-forward-lean" target="_blank" rel="noopener noreferrer">excessive forward lean</a>. Based on this research the BI categorizes the AOS as over-active. The Brookbush Institute addresses this issue with &#x201C;release and avoid.&#x201D; That is, the muscle&#xA0;and fascial structures that can be released are addressed, and exercises that place emphasis on the <a href="https://brookbushinstitute.com/courses/anterior-oblique-subsystem-aos" target="_blank" rel="noopener">AOS</a> are avoided until movement quality improves (for example, avoid <a href="https://brookbushinstitute.com/courses/plank-progression" target="_blank" rel="noopener">planks</a>, crunches, leg raises, etc.).</div>
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 </div>
 Alternatively, in an <a href="https://brookbushinstitute.com/video/overhead-squat-assessment-9-anterior-pelvic-tilt-excessive-lordosis" target="_blank" rel="noopener">anterior pelvic tilt</a>, the <a title="External Obliques" href="https://brookbushinstitute.com/courses/external-obliques" target="_blank" rel="noopener">external obliques</a> and <a title="Rectus Abdominis" href="https://brookbushinstitute.com/courses/rectus-abdominis-pyramidalis" target="_blank" rel="noopener">rectus abdominis</a> are long, which creates a puzzling combination of both short and long muscles in the <a href="https://brookbushinstitute.com/courses/anterior-oblique-subsystem-aos" target="_blank" rel="noopener">AOS</a> and over-activity throughout. In this case, the Brookbush Institute has found <a href="https://brookbushinstitute.com/courses/chop-pattern-progression" target="_blank" rel="noopener">chop patterns</a> (integrating <a href="https://brookbushinstitute.com/courses/rectus-abdominis-pyramidalis" target="_blank" rel="noopener">anterior abdominal muscles</a> and <a href="https://brookbushinstitute.com/courses/gluteus-maximus" target="_blank" rel="noopener">glute complex</a> activity), and <a href="https://brookbushinstitute.com/courses/anterior-oblique-subsystem-aos" target="_blank" rel="noopener">AOS</a>&#xA0;integration followed immediately by <a href="https://brookbushinstitute.com/courses/posterior-oblique-subsystem-pos" target="_blank" rel="noopener">POS</a> integration very helpful. Generally, the result of this progression is from an <a href="https://brookbushinstitute.com/video/overhead-squat-assessment-9-anterior-pelvic-tilt-excessive-lordosis" target="_blank" rel="noopener">anterior pelvic tilt</a> to an <a href="https://brookbushinstitute.com/video/overhead-squat-assessment-8-excessive-forward-lean" target="_blank" rel="noopener noreferrer">excessive forward lean</a>, followed by improvement of the <a href="https://brookbushinstitute.com/video/overhead-squat-assessment-8-excessive-forward-lean" target="_blank" rel="noopener noreferrer">excessive forward lean</a> with <a href="https://brookbushinstitute.com/courses/posterior-oblique-subsystem-pos" target="_blank" rel="noopener">POS</a> integration.
 </div>
 </div>
 </div>
</div>
<div tabindex="0">
 <div tabindex="0">
 <div tabindex="0">
 <h3 tabindex="0">Instrument Assisted Soft Tissue Mobilization (IASTM) of the Abdominal Fascia:</h3>
 <div tabindex="0">Fascia&apos;s response to specific intervention is complex. Responses may include strain hardening with repetitive or constant tension, enhanced shear and a reduction in cross-bridging between fascial layers, changes in both muscle tone and fibroblast mediated pre-tension (with sustained pressure), and/or altered transmission of force of multiple muscles acting to stabilize a joint (136-138). As mentioned above, one study implied deep, slow pressure to the abdominal region resulted in a decrease in <a class="glossaryLink " title="Glossary: Muscle cell" href="https://brookbushinstitute.com/glossary/muscle-cell/" target="_blank" rel="noopener" data-cmtooltip="&lt;div class=glossaryItemTitle&gt;Muscle cell&lt;/div&gt;Muscle Cells - These cells are specialized to respond to stimulation with contraction (movement) and are relatively elastic. There are 3 types of muscle cells/tissues; skeletal (striated), cardiac and smooth.&lt;br /&gt;&lt;br /&gt;Of the 3 types of muscles cells, skeletal muscle is the only type that allows for voluntary control.&lt;br /&gt;&lt;ol&gt;&lt;br /&gt; &lt;li&gt;Saladin, K. (2014). Anatomy &amp; physiology: The unity of form and function. McGraw-Hill Higher Education, New York. ISBN: 9780073403717&lt;/li&gt;&lt;br /&gt;&lt;/ol&gt;" style="background: transparent; color: #34363a; text-decoration: underline; box-sizing: border-box; border: 0px; font-style: inherit; font-variant: inherit; font-weight: inherit; font-stretch: inherit; font-size: inherit; font-family: inherit; line-height: 1.4; margin: 0px; padding: 0px; vertical-align: baseline;">muscle</a> activity (5). This may be an example of a manual technique altering fibroblast mediated pre-tension, but more research is needed to support or refute this claim. If manual pressure is applied a tangential force is recommended to reduce discomfort. No studies could be located that investigated IASTM on the abdominal region, but based on the idea that shear between layers may be reduced as a result of dysfunction, careful application in practice may be warranted, especially where the layers converge at the semilunar lines. Careful re-assessment is recommended (as recommended with all techniques) to determine the efficacy on an individual basis.</div>
 </div>
 </div>
</div>

Influence on Intervention

<div tabindex="0">
 <h3>Subsystems Summary</h3>
 <table>
 <tbody>
 <tr>
 <td width="151">Subsystem</td>
 <td width="216">Common Behavior</td>
 <td width="151">Core</td>
 <td width="133">Integration </td>
 </tr>
 <tr>
 <td width="151"><a href="https://brookbushinstitute.com/courses/intrinsic-stabilization-subsystem" target="_blank" rel="noopener">Intrinsic Stabilization Subsystem (ISS)</a>
 
 
 </td>
 <td width="216">Under-active</td>
 <td width="151">Transverse Abdominis (TVA) Activation</td>
 <td width="133">N/A</td>
 </tr>
 <tr>
 <td width="151">Anterior Oblique Subsystem (AOS)</td>
 <td width="216">Over-active</td>
 <td width="151">
 <span style="background-color: transparent; font-family: inherit; font-size: inherit; font-style: inherit; font-variant-ligatures: inherit; font-variant-caps: inherit; font-weight: inherit; color: var(--color); letter-spacing: 0px;"><a href="https://brookbushinstitute.com/courses/chop-pattern-progressions" target="_blank" style="letter-spacing: 0px;" rel="noopener">Chop Progression</a>
 Avoid: planks, crunches, resisted hip flexion
 </td>
 <td width="133">Legs with Push</td>
 </tr>
 <tr>
 <td width="151"><a href="https://brookbushinstitute.com/courses/posterior-oblique-subsystem-pos" target="_blank" rel="noopener">Posterior Oblique Subsystem (POS)</a>
 
 
 </td>
 <td width="216">Under-active</td>
 <td width="151"><a href="https://brookbushinstitute.com/courses/chop-pattern-progressions" target="_blank" rel="noopener">Chop Progression </a> and <a href="https://brookbushinstitute.com/courses/bridge-progression" target="_blank" rel="noopener">Bridge Progression</a></td>
 <td width="133">Legs with Pull</td>
 </tr>
 <tr>
 <td width="151"><a href="https://brookbushinstitute.com/courses/deep-longitudinal-subsystem" target="_blank" rel="noopener">Deep Longitudinal Subsystem (DLS)</a></td>
 <td width="216">Over-active</td>
 <td width="151">Avoid: leg curls, lumbar extensions</td>
 <td width="133">Avoid: straight-leg deadlifts, kettle bell windmills, Nordic curls</td>
 </tr>
 </tbody>
 </table>
 <h3>Signs of AOS Dysfunction</h3>
 <ul>
 <li> <a href="https://brookbushinstitute.com/courses/solutions-table-overhead-squat-assessment" target="_blank" rel="noopener"> Overhead Squat </a><a id="assessment" data-tip="1478" target="_blank" href="/glossary-term/assessment" class="glossary">Assessment</a> 
 <ul>
 <li><a href="https://brookbushinstitute.com/video/overhead-squat-assessment-9-anterior-pelvic-tilt-excessive-lordosis" target="_blank" rel="noopener"> </a><a id="anterior" data-tip="1566" target="_blank" href="/glossary-term/anterior" class="glossary">Anterior</a> Pelvic Tilt (Under-active)</li>
 <li><a href="https://brookbushinstitute.com/video/overhead-squat-assessment-8-excessive-forward-lean" target="_blank" rel="noopener"> Excessive Forward Lean</a> (Over-active)</li>
 <li><a href="https://brookbushinstitute.com/video/overhead-squat-assessment-15-sign-clusters-asymmetrical-weight-shift/" target="_blank" rel="noopener">Asymmetrical Weight Shift</a> (Over-active)</li>
 <li><a href="https://brookbushinstitute.com/video/overhead-squat-assessment-10-arms-fall" target="_blank" rel="noopener"> Arms Fall</a> (Over-active)</li>
 </ul>
 </li>
 </ul>
 Practical Application
 <ul>
 <li>Core
 <ul>
 <li><a href="https://brookbushinstitute.com/article/axe-chop-progression" target="_blank" rel="noopener">Static Chop Progression</a></li>
 <li><a href="https://brookbushinstitute.com/article/plank-progression" target="_blank" rel="noopener">Plank and Progressions</a></li>
 </ul>
 </li>
 <li>Integrated Exercise
 <ul>
 <li><a href="https://brookbushinstitute.com/article/stability-progression-for-integrated-exercise" target="_blank" rel="noopener">Legs with Push</a></li>
 </ul>
 </li>
 </ul>
 <h3>AOS Integration &quot;Legs with Push&quot; Progression</h3>
 <ol>
 <li>Step-Up to Chest Press</li>
 <li>Step-Up to <a id="unilateral" data-tip="1551" target="_blank" href="/glossary-term/unilateral" class="glossary">Unilateral</a> Chest Press</li>
 <li>Step-Up to <a id="balance" data-tip="1190" target="_blank" href="/glossary-term/balance" class="glossary">Balance</a> to Chest Press</li>
 <li>Step-Up to <a id="balance" data-tip="1190" target="_blank" href="/glossary-term/balance" class="glossary">Balance</a> to <a id="unilateral" data-tip="1551" target="_blank" href="/glossary-term/unilateral" class="glossary">unilateral</a> Chest Press</li>
 <li>Frontal Plane Step-Up to <a id="balance" data-tip="1190" target="_blank" href="/glossary-term/balance" class="glossary">balance</a> to Chest Press</li>
 <li>Frontal Plane Step-Up to <a id="balance" data-tip="1190" target="_blank" href="/glossary-term/balance" class="glossary">balance</a> to <a id="unilateral" data-tip="1551" target="_blank" href="/glossary-term/unilateral" class="glossary">unilateral</a> Chest Press</li>
 <li>Transverse Plane Step-Up to <a id="balance" data-tip="1190" target="_blank" href="/glossary-term/balance" class="glossary">balance</a> to Chest Press</li>
 <li>Transverse Plane Step-Up to <a id="balance" data-tip="1190" target="_blank" href="/glossary-term/balance" class="glossary">balance</a> to <a id="unilateral" data-tip="1551" target="_blank" href="/glossary-term/unilateral" class="glossary">unilateral</a> Chest Press</li>
 <li>Reverse Lunge to Chest Press</li>
 <li>Reverse Lunge to Contra-lateral Chest Press</li>
 <li>Transverse Plane Lunge to <a id="contralateral" data-tip="1549" target="_blank" href="/glossary-term/contralateral" class="glossary">Contralateral</a> Chest Press</li>
 <li>Reverse Lunge to Single Leg <a id="balance" data-tip="1190" target="_blank" href="/glossary-term/balance" class="glossary">Balance</a> to Chest Press</li>
 <li>Reverse Lunge to Single Leg <a id="balance" data-tip="1190" target="_blank" href="/glossary-term/balance" class="glossary">Balance</a> to <a id="unilateral" data-tip="1551" target="_blank" href="/glossary-term/unilateral" class="glossary">Unilateral</a> Chest Press</li>
 <li>Transverse Plane Lunge to Single Leg <a id="balance" data-tip="1190" target="_blank" href="/glossary-term/balance" class="glossary">Balance</a> to <a id="contralateral" data-tip="1549" target="_blank" href="/glossary-term/contralateral" class="glossary">Contralateral</a> Chest Press</li>
 </ol>
 <hr>
 <h3>Optimal Form:</h3>
 <a id="optimal" data-tip="1571" target="_blank" href="/glossary-term/optimal" class="glossary">Optimal</a> <a id="posture" data-tip="1660" target="_blank" href="/glossary-term/posture" class="glossary">form</a> for any exercise should be modeled with the intent of reducing signs that have been correlated with an increased risk of future pain an injury (e.g. absence of forward head, knees bow in, etc.). Generally, this results in cues that focus on the alignment of joints.
 <ul>
 <li>Feet parallel and hip-width
 <ul>
 <li>2nd toe pointing forward and under the <a id="anterior" data-tip="1566" target="_blank" href="/glossary-term/anterior" class="glossary">anterior</a> <a id="superior" data-tip="1570" target="_blank" href="/glossary-term/superior" class="glossary">superior</a> iliac spine (ASIS)</li>
 </ul>
 </li>
 <li>Ankle, knees, and hips in alignment</li>
 <li>Neutral pelvis (no <a id="anterior" data-tip="1566" target="_blank" href="/glossary-term/anterior" class="glossary">anterior</a> pelvic tilt)</li>
 <li>Neutral lumbar spine with abdominal <a id="drawing-in" data-tip="1580" target="_blank" href="/glossary-term/drawing-in" class="glossary">drawing-in</a> maneuver (<a id="drawing-in" data-tip="1588" target="_blank" href="/glossary-term/drawing-in" class="glossary">ADIM</a>)</li>
 <li>Tibia and torso parallel</li>
 <li>Cervical and thoracic spine in <a id="optimal" data-tip="1571" target="_blank" href="/glossary-term/optimal" class="glossary">optimal</a> alignment (head back with chin tucked)</li>
 <li>Scapula and shoulders in neutral position</li>
 </ul>
</div>

Best-use and Progressions

Videos

Step Up to Chest Press

Dynamic Lunge to Press

Sled Push

Bibliography

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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