Introduction: Prevalence of Gluteus Medius Weakness with Nonspecific Low Back Pain

How Does this Relate to Brookbush Institute Content: Impaired Core Stability Is Predictor of Knee Injury Risk

Introduction: The Impact of Hip Strength on Trunk and Lower Extremity Coordination During Walking and Hopping

Study Summary: The Impact of Hip Strength on Trunk and Lower Extremity Coordination During Walking and Hopping

How this Study Contributes to the Body of Research: The Impact of Hip Strength on Trunk and Lower Extremity Coordination During Walking and Hopping

How the Findings Apply to Practice: The Impact of Hip Strength on Trunk and Lower Extremity Coordination During Walking and Hopping

How Does this Study Relate to Brookbush Institute Content: The Impact of Hip Strength on Trunk and Lower Extremity Coordination During Walking and Hopping

Study Summary: Prevalence of Gluteus Medius Weakness with Nonspecific Low Back Pain

How this Study Contributes to the Body of Research: Prevalence of Gluteus Medius Weakness with Nonspecific Low Back Pain

How the Findings Apply to Practice: Prevalence of Gluteus Medius Weakness with Nonspecific Low Back Pain

How Does this Study Relate to Brookbush Institute Content: Prevalence of Gluteus Medius Weakness with Nonspecific Low Back Pain

Introduction: Impaired Core Stability Is Predictor of Knee Injury Risk

Study Summary: Impaired Core Stability Is Predictor of Knee Injury Risk

How this Study Contributes to the Body of Research: Impaired Core Stability Is Predictor of Knee Injury Risk

How the Findings Apply to Practice: Impaired Core Stability Is Predictor of Knee Injury Risk

Regional Interdependence: Trunk and Lower Extremity

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Prevalence of Gluteus Medius Weakness with Nonspecific Low Back Pain

Original Citation: Cooper, N. A., Scavo, K. M., Strickland, K. J., Tipayamongkol, N., Nicholson, J. D., Bewyer, D. C., &amp; Sluka, K. A. (2016). Prevalence of gluteus medius weakness in people with chronic low back pain compared to healthy controls. European Spine Journal, 25(4), 1258-1265. - <a href="https://www.researchgate.net/profile/Kathleen_Sluka/publication/277252736_Prevalence_of_gluteus_medius_weakness_in_people_with_chronic_low_back_pain_compared_to_healthy_controls/links/5665fa5508ae192bbf9276d9/Prevalence-of-gluteus-medius-weakness-in-people-with-chronic-low-back-pain-compared-to-healthy-controls.pdf" target="_blank" rel="noopener">ARTICLE</a>
Low back pain (LBP) is the leading cause of disability worldwide (1). A growing body of research is demonstrating a correlation between myofascial pain, myofascial <a id="trigger-point" data-tip="1634" target="_blank" href="/glossary-term/trigger-point" class="glossary">trigger points</a>, weakness, and altered recruitment patterns of the <a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">hip</a> abductor musculature and LBP (2-10). This 2015 study by U.S. researchers demonstrates that chronic non-specific LBP was most strongly correlated with <a id="ipsilateral" data-tip="1550" target="_blank" href="/glossary-term/ipsilateral" class="glossary">ipsilateral</a> <a href="https://brookbushinstitute.com/article/gluteus-medius" target="_blank" rel="noopener">gluteus medius</a> weakness and gluteal tenderness, and also correlated with <a id="ipsilateral" data-tip="1550" target="_blank" href="/glossary-term/ipsilateral" class="glossary">ipsilateral</a> erector and trochanteric tenderness and greater strength of the <a id="contralateral" data-tip="1549" target="_blank" href="/glossary-term/contralateral" class="glossary">contralateral</a> <a href="https://brookbushinstitute.com/article/tensor-fascia-latae-tfl" target="_blank" rel="noopener">tensor fascia latae</a>. Human movement professionals working with individuals with LBP should consider assessing these issues and addressing any noted impairments as part of a comprehensive treatment plan.
<a href="https://www.datocms-assets.com/25800/1646160329-brookbush-gluteus-medius-1.jpeg"><img src="https://www.datocms-assets.com/25800/1646160329-brookbush-gluteus-medius-1.jpeg"></a> Karl Sterling, BI Presenter prepping to teach Gluteus Medius Activation

Introduction

<table>
 <tbody>
 <tr>
 <td width="40%">Study Design</td>
 <td>Case-control Study</td>
 </tr>
 <tr>
 <td>Level of Evidence</td>
 <td>IIB Evidence from at least one other type of quasi-experimental study</td>
 </tr>
 <tr>
 <td>Participant Characteristics</td>
 <td>
 Chronic Low Back Pain (LBP) Study Group
 Demographics
 <ul>
 <li>Age: 41.4 +/- 13 years</li>
 <li>Gender: 64.7% female</li>
 <li>Characteristics:
 <ul>
 <li>Height: 169.4 +/- 11.4 cm</li>
 <li>Weight: 84.9 +/- 22.2 kg</li>
 <li>BMI: 29.6 +/- 7.2 kg/m&#xB2;</li>
 </ul>
 </li>
 <li>Number of participants: 150</li>
 <li>Individuals with chronic non-specific LBP</li>
 </ul>
 Inclusion Criteria:
 <ul>
 <li>Non-specific LBP (pain anywhere from the <a id="inferior" data-tip="1569" target="_blank" href="/glossary-term/inferior" class="glossary">inferior</a> rib margin to the gluteal fold) for greater than 3 months</li>
 </ul>
 Exclusion Criteria:
 <ul>
 <li>Diagnosed <a id="etiology" data-tip="1489" target="_blank" href="/glossary-term/etiology" class="glossary">etiology</a> of LBP such as: radiculopathy, neurogenic claudication, fracture, primary or secondary spinal tumors, or other <a id="specificity" data-tip="1224" target="_blank" href="/glossary-term/specificity" class="glossary">specific</a> pathology</li>
 </ul>
 Control Group
 Demographics
 <ul>
 <li>Age: 40.7 +/- 13.9 years</li>
 <li>Gender: 65.3% female</li>
 <li>Characteristics:
 <ul>
 <li>Height: 168.2 +/- 9.4 cm</li>
 <li>Weight: 73.2 +/- 21.2 kg</li>
 <li>BMI: 25.8 +/- 7.0 kg/m&#xB2;</li>
 </ul>
 </li>
 <li>Number of participants: 75</li>
 <li>Individuals without a history of LBP</li>
 </ul>
 Inclusion Criteria:
 <ul>
 <li>No report of current LBP</li>
 <li>No history of more than 3 months of LBP</li>
 </ul>
 Exclusion Criteria:
 <ul>
 <li>History of more than 3 months of LBP</li>
 </ul>
 </td>
 </tr>
 <tr>
 <td>Methodology</td>
 <td>
 <ul>
 <li>Participants were screened to identify any symptoms suggestive of a <a id="specificity" data-tip="1224" target="_blank" href="/glossary-term/specificity" class="glossary">specific</a> pathology:
 <ul>
 <li>Subjective questioning</li>
 <li>Physical examination for:
 <ul>
 <li>Reflex asymmetry</li>
 <li>Myotomal weakness</li>
 <li>Sensory disturbance</li>
 <li>Straight leg raise</li>
 <li>Groin pain with <a href="https://brookbushinstitute.com/article/kinesiology-of-the-hip" target="_blank" rel="noopener">hip</a> internal rotation</li>
 </ul>
 
 </li>
 </ul>
 </li>
 <li>Participants were assessed for <a href="https://brookbushinstitute.com/article/kinesiology-of-the-hip" target="_blank" rel="noopener">hip</a> <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> strength and tenderness:
 <ul>
 <li>Manual <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> Testing (MMT):
 <ul>
 <li><a href="https://brookbushinstitute.com/article/gluteus-medius" target="_blank" rel="noopener">Gluteus Medius</a></li>
 <li><a href="https://brookbushinstitute.com/article/tensor-fascia-latae-tfl" target="_blank" rel="noopener">Tensor Fascia Latae (TFL)</a></li>
 <li><a href="https://brookbushinstitute.com/article/gluteus-maximus" target="_blank" rel="noopener">Gluteus Maximus</a></li>
 </ul>
 </li>
 <li>Trendelenburg sign in single-leg stance as a functional measure of <a href="https://brookbushinstitute.com/article/gluteus-medius" target="_blank" rel="noopener">gluteus medius</a> strength</li>
 <li>Tenderness upon palpation assessed bilaterally:
 <ul>
 <li>Gluteals</li>
 <li>Greater trochanter</li>
 <li>Lumbar paraspinals</li>
 <li><a href="https://brookbushinstitute.com/article/piriformis" target="_blank" rel="noopener">Piriformis</a></li>
 </ul>
 
 </li>
 </ul>
 </li>
 <li>Inter-rater <a id="reliability" data-tip="1515" target="_blank" href="/glossary-term/reliability" class="glossary">reliability</a> assessed for all 4 examiners</li>
 </ul>
 </td>
 </tr>
 <tr>
 <td>Data Collection and Analysis</td>
 <td>Data Analysis
 <ul>
 <li>Data from the chronic LBP group was divided into affected and unaffected sides with <a id="bilateral" data-tip="1552" target="_blank" href="/glossary-term/bilateral" class="glossary">bilateral</a> complaints treated as both sides affected.</li>
 <li>Age, height, weight, and BMI were compared with independent sample t-tests.</li>
 <li>MMT between groups and sides were calculated with Friedman&apos;s <a id="assessment" data-tip="1482" target="_blank" href="/glossary-term/assessment" class="glossary">test</a> with post hoc corrections for multiple comparisons.</li>
 <li>Trendelenburg sign and tenderness were calculated between groups and sides with Cochran&apos;s Q corrected for multiple comparisons.</li>
 <li>Differences in prevalence between groups were compared with a Mann-Whitney U <a id="assessment" data-tip="1482" target="_blank" href="/glossary-term/assessment" class="glossary">test</a>.</li>
 <li>Hierarchical linear <a id="exercise-regression" data-tip="1179" target="_blank" href="/glossary-term/exercise-regression" class="glossary">regression</a> was performed to identify predictors of the presence of LBP in the total sample with demographic differences treated as covariates.
 <ul>
 <li>Regression was performed forward and backward with p&lt;0.05 for entry criterion and p&gt;0.1 for exit criterion.</li>
 </ul>
 
 </li>
 <li>Inter-rater <a id="reliability" data-tip="1515" target="_blank" href="/glossary-term/reliability" class="glossary">reliability</a> for MMT, Trendelenburg sign, and tenderness was calculated with a two-way random effects <a id="model" data-tip="1469" target="_blank" href="/glossary-term/model" class="glossary">model</a>.</li>
 <li>Significance was set at p=0.01 for all tests.</li>
 </ul>
 </td>
 </tr>
 <tr>
 <td>Outcome Measures</td>
 <td>
 Low Back Pain
 Strength
 <ul>
 <li>MMT grade (1-5) for:
 <ul>
 <li><a href="https://brookbushinstitute.com/article/gluteus-medius" target="_blank" rel="noopener">Gluteus Medius</a></li>
 <li><a href="https://brookbushinstitute.com/article/tensor-fascia-latae-tfl" target="_blank" rel="noopener">TFL</a></li>
 <li><a href="https://brookbushinstitute.com/article/gluteus-maximus" target="_blank" rel="noopener">Gluteus Maximus</a></li>
 </ul>
 </li>
 <li>Presence of the Trendelenburg sign</li>
 </ul>
 Tenderness on Palpation
 <ul>
 <li>Gluteals</li>
 <li>Greater trochanter</li>
 <li>Lumbar paraspinals</li>
 <li><a href="https://brookbushinstitute.com/article/piriformis" target="_blank" rel="noopener">Piriformis</a></li>
 </ul>
 </td>
 </tr>
 <tr>
 <td>Results</td>
 <td>Strength (reported as MMT grade +/- standard deviation)
 <ul>
 <li><a href="https://brookbushinstitute.com/article/gluteus-medius" target="_blank" rel="noopener">Gluteus Medius</a> strength was significantly decreased for the affected side (3.35 +/- 0.73) compared to the unaffected side or control group.
 <ul>
 <li>Unaffected side: 4.56 +/- 0.66, p&lt;0.001</li>
 <li>Control group: 4.46 +/- 0.50, p&lt;0.001</li>
 </ul>
 </li>
 <li><a href="https://brookbushinstitute.com/article/tensor-fascia-latae-tfl" target="_blank" rel="noopener">TFL</a> strength was significantly greater for the unaffected side (4.93 +/- 0.26) compared to controls but not the affected side.
 <ul>
 <li>Control group: 4.48 +/- 0.50, p&lt;0.001</li>
 <li>Affected side: 4.81 +/- 0.44</li>
 </ul>
 </li>
 <li>No significant difference in <a href="https://brookbushinstitute.com/article/gluteus-maximus" target="_blank" rel="noopener">gluteus maximus</a> strength.</li>
 </ul>
 Trendelenburg Sign
 <ul>
 <li>More frequently present on the affected side (54.2%) compared to the unaffected side for the control group.
 <ul>
 <li>Unaffected side: 7.1%, p&lt;0.001</li>
 <li>Control group: 9.7%, p&lt;0.001</li>
 </ul>
 
 </li>
 </ul>
 Tenderness on Palpation
 <ul>
 <li>Gluteal tenderness was more prevalent on the affected side (68.1%) compared to the unaffected side or control group.
 <ul>
 <li>Unaffected side: 4.8%, p&lt;0.001</li>
 <li>Control group: 11.2%, p&lt;0.001</li>
 </ul>
 </li>
 <li>Greater trochanter tenderness was more prevalent on the affected side (44.9%) compared to the unaffected side or control group.
 <ul>
 <li>Unaffected side: 6.0%, p&lt;0.001</li>
 <li>Control group: 6.0%, p&lt;0.001</li>
 </ul>
 </li>
 <li>Lumbar paraspinal tenderness was more prevalent on the affected side (53.2%) compared to the unaffected side or control group.
 <ul>
 <li>Unaffected side: 23.8%, p&lt;0.001</li>
 <li>Control group: 0.7%, p&lt;0.001</li>
 </ul>
 </li>
 <li>There was no significant difference in <a href="https://brookbushinstitute.com/article/piriformis" target="_blank" rel="noopener">piriformis</a> tenderness.</li>
 </ul>
 Correlation with LBP
 <ul>
 <li>The strongest contributor was <a href="https://brookbushinstitute.com/article/gluteus-medius" target="_blank" rel="noopener">gluteus medius</a> weakness on the affected side (DR&#xB2; = 0.461, p&lt;0.001)</li>
 </ul>
 Inter-class Correlation Coefficient (ICC)
 <ul>
 <li>ICC for MMT was 0.597 (0.331-0.774, 95% confidence interval).</li>
 <li>There was perfect <a id="reliability" data-tip="1515" target="_blank" href="/glossary-term/reliability" class="glossary">reliability</a> among Trendelenburg sign and <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> tenderness examination.</li>
 </ul>
 </td>
 </tr>
 <tr>
 <td>Our Conclusions</td>
 <td>The results of this study demonstrate that increased BMI, <a href="https://brookbushinstitute.com/article/gluteus-medius" target="_blank" rel="noopener">gluteus medius</a> weakness, ipsilateral muscle tenderness, and potentially greater contralateral <a href="https://brookbushinstitute.com/article/tensor-fascia-latae-tfl" target="_blank" rel="noopener">TFL</a> strength are associated with chronic non-specific LBP. This may imply that a predictable set of compensatory changes may be indicative of risk for future low back pain. These compensatory changes are similar to those mentioned in the Brookbush Institute&#x2019;s <a href="https://brookbushinstitute.com/glossary/model/" target="_blank" rel="noopener">model</a> of <a href="https://brookbushinstitute.com/article/lumbo-pelvic-hip-complex-dysfunction-lphcd" target="_blank" rel="noopener">Lumbo Pelvic Hip Complex Dysfunction (LPHCD)</a>.</td>
 </tr>
 <tr>
 <td>Researchers&apos; Conclusions
 
 </td>
 <td><a href="https://brookbushinstitute.com/article/gluteus-medius" target="_blank" rel="noopener">Gluteus Medius</a> weakness and associated tenderness are common symptoms in individuals with chronic non-specific LBP. Assessment and treatment of <a href="https://brookbushinstitute.com/article/gluteus-medius" target="_blank" rel="noopener">gluteus medius</a> muscle dysfunction may enhance clinical decision making and treatment outcomes for individuals with LBP.</td>
 </tr>
 </tbody>
</table>
<a href="https://www.datocms-assets.com/25800/1646161075-gluteus-medius-mmt-1024x545.png"><img src="https://www.datocms-assets.com/25800/1646161075-gluteus-medius-mmt-1024x545.png"></a> Gluteus Medius Manual <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">Muscle</a> Testing. (Image: Courtesy of www.BrentBrookbush.com)

Study Summary

The relationships between low back pain (LBP) and <a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">hip</a> abductor <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> weakness highlight the interdependence of the trunk and hip musculature, as well as the predictable changes in motor recruitment associated with dysfunction (2-10). Previous research has shown a correlation between <a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">hip</a> abductor weakness and LBP, but examined frontal plane <a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">hip</a> abduction strength, without attempting to differentiate contributions from the <a href="https://brookbushinstitute.com/article/tensor-fascia-latae-tfl" target="_blank" rel="noopener">tensor fascia latae (TFL)</a> and <a href="https://brookbushinstitute.com/article/gluteus-medius" target="_blank" rel="noopener">gluteus medius</a> (6-7). Unique to this study, the researchers investigated the strength of the <a href="https://brookbushinstitute.com/article/gluteus-medius" target="_blank" rel="noopener">gluteus medius</a>, <a href="https://brookbushinstitute.com/article/tensor-fascia-latae-tfl" target="_blank" rel="noopener">TFL</a>, and <a href="https://brookbushinstitute.com/article/gluteus-maximus" target="_blank" rel="noopener">gluteus maximus</a> muscles individually in those with chronic LBP. Further, this study added additional information regarding tenderness of the lumbar and <a id="posterior" data-tip="1565" target="_blank" href="/glossary-term/posterior" class="glossary">posterior</a> hip regions. This study demonstrates that a strong correlation exists between <a href="https://brookbushinstitute.com/article/gluteus-medius" target="_blank" rel="noopener">gluteus medius</a> weakness, gluteal tenderness, and chronic LBP.

How this Study Contributes to the Body of Research

The strongest correlation found in this study was between low back pain (LBP) and decreased <a href="https://brookbushinstitute.com/article/gluteus-medius" target="_blank" rel="noopener">gluteus medius</a> strength. This may imply interdependence between trunk and hip muscles and suggest that patients/clients with LBP should also be assessed for <a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">hip</a> impairments. Human movement professionals should consider adding <a href="https://brookbushinstitute.com/article/gluteus-medius-activation-progression" target="_blank" rel="noopener">gluteus medius activation exercises</a> to their repertoire of potential interventions for LBP for those individuals with assessed weakness.
This study had many methodological strengths, including:
<ul>
 <li>Strength testing was performed on the affected and unaffected extremities and correlations were investigated to determine the relationship to the location of the participant&apos;s symptoms.</li>
 <li>Inter-rater <a href="https://brookbushinstitute.com/glossary/reliability/" target="_blank" rel="noopener">reliability</a> was calculated through intra-class correlation coefficients (ICCs), demonstrating significance and <a href="https://brookbushinstitute.com/glossary/reliability/" target="_blank" rel="noopener">reliability</a> for the data collected.</li>
 <li>The examination procedures used in this study were those commonly used in rehabilitation settings, allowing the practitioner to refine their examination selection to <a href="https://brookbushinstitute.com/article/gluteus-medius" target="_blank" rel="noopener">gluteus medius</a> testing that elicits the lowest <a href="https://brookbushinstitute.com/article/tensor-fascia-latae-tfl" target="_blank" rel="noopener">TFL</a> activity.</li>
</ul>
Weaknesses that should be noted prior to the clinical <a id="integration" data-tip="1472" target="_blank" href="/glossary-term/integration" class="glossary">integration</a> of the findings include:
<ul>
 <li>Participants in each group were not matched for height and weight; the LBP group had a higher BMI than the control group.</li>
 <li>The researchers did not incorporate EMG data in their analysis, which may have provided more <a id="reliability" data-tip="1795" target="_blank" href="/glossary-term/reliability" class="glossary">reliable</a> information on <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> activity than manual <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> testing.</li>
 <li>Algometry was not used to determine the level of tenderness. Having an objective measure of pressure <a id="sensitivity" data-tip="1226" target="_blank" href="/glossary-term/sensitivity" class="glossary">sensitivity</a> would have allowed for more detailed statistics.</li>
</ul>

How the Findings Apply to Practice

The Brookbush Institute (BI) has developed <a href="https://brookbushinstitute.com/article/introduction-to-postural-dysfunction-and-movement-impairment" target="_blank" rel="noopener">predictive </a><a id="model" data-tip="1471" target="_blank" href="/glossary-term/model" class="glossary">models</a> of <a id="posture" data-tip="1659" target="_blank" href="/glossary-term/posture" class="glossary">postural</a> dysfunction based on evidence of common tissue changes (<a href="https://brookbushinstitute.com/glossary/muscle-cell/" target="_blank" rel="noopener">muscle</a>, joint, fascia, and <a href="https://brookbushinstitute.com/glossary/nerve-cell/" target="_blank" rel="noopener">nerve</a>) to aid human movement professionals in selecting <a href="https://brookbushinstitute.com/glossary/optimal/" target="_blank" rel="noopener">optimal</a> <a href="https://brookbushinstitute.com/glossary/assessment/" target="_blank" rel="noopener">assessments</a>, manual interventions, and exercise. This study demonstrates that a decrease in <a href="https://brookbushinstitute.com/article/gluteus-medius" target="_blank" rel="noopener">gluteus medius</a> strength is correlated with chronic low back pain (LBP). The findings of this study were <a id="integration" data-tip="1473" target="_blank" href="/glossary-term/integration" class="glossary">integrated</a> with additional studies demonstrating a correlation between <a href="https://brookbushinstitute.com/article/gluteus-medius" target="_blank" rel="noopener">gluteus medius</a> inhibition and <a href="https://brookbushinstitute.com/article/lumbo-pelvic-hip-complex-dysfunction-lphcd" target="_blank" rel="noopener">Lumbo Pelvic Hip Complex Dysfunction (LPHCD)</a>. The BI will continue to pursue <a id="optimal" data-tip="1571" target="_blank" href="/glossary-term/optimal" class="glossary">optimal</a> practice by refining <a href="https://brookbushinstitute.com/article/introduction-to-postural-dysfunction-and-movement-impairment" target="_blank" rel="noopener">predictive </a><a id="model" data-tip="1471" target="_blank" href="/glossary-term/model" class="glossary">models</a> of <a id="posture" data-tip="1659" target="_blank" href="/glossary-term/posture" class="glossary">postural</a> dysfunction, using the aggregated results of all available evidence.

How Does this Study Relate to Brookbush Institute Content

Gluteus Medius Manual <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">Muscle</a> Testing
<iframe src="https://player.vimeo.com/video/136539407" frameborder="0" allowfullscreen="allowfullscreen"></iframe>
Gluteus Activation Taping
<iframe src="https://player.vimeo.com/video/125297635" frameborder="0" allowfullscreen="allowfullscreen"></iframe>
Gluteus Medius Activation
<iframe src="https://player.vimeo.com/video/82856186" frameborder="0" allowfullscreen="allowfullscreen"></iframe>
Gluteus Medius Activation Progression
<iframe src="https://player.vimeo.com/video/82857653" frameborder="0" allowfullscreen="allowfullscreen"></iframe>
Quick Gluteus Medius and Gluteus Maximus Activation Progression
<iframe src="https://player.vimeo.com/video/100443002" frameborder="0" allowfullscreen="allowfullscreen"></iframe>
Gluteus Medius and Gluteus Maximus Reactive Activation: Side Hop Progression
<iframe src="https://player.vimeo.com/video/76692013" frameborder="0" allowfullscreen="allowfullscreen"></iframe>

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Impaired Core Stability Is Predictor of Knee Injury Risk

Original Citation: Zazulak, B. T., Hewett, T. E., Reeves, N. P., Goldberg, B., and Cholewicki, J. (2007). Deficits in neuromuscular control of the trunk predict knee injury risk. The American journal of sports medicine, 35(7), 1123-1130. <a href="https://www.researchgate.net/profile/Norman_Reeves/publication/6362341_Deficits_in_Neuromuscular_Control_of_the_Trunk_Predict_Knee_Injury_Risk_A_Prospective_Biomechanical-Epidemiologic_Study/links/00b7d525bf496c69d7000000/Deficits-in-Neuromuscular-Control-of-the-Trunk-Predict-Knee-Injury-Risk-A-Prospective-Biomechanical-Epidemiologic-Study.pdf" target="_blank" rel="noopener">ARTICLE</a>
The <a href="https://brookbushinstitute.com/article/knee" target="_blank" rel="noopener">knee</a> joint is the second most commonly injured body part, and <a href="https://brookbushinstitute.com/article/knee" target="_blank" rel="noopener">knee</a> surgeries account for as much as 60% of all sports-related surgeries (1-2). Research is starting to imply that dynamic <a id="stability" data-tip="1191" target="_blank" href="/glossary-term/stability" class="glossary">stability</a> of the <a href="https://brookbushinstitute.com/article/knee" target="_blank" rel="noopener">knee</a> depends on the ability to react to changes in trunk position during cutting, stopping, and landing movements (3-4). This 2007 study by U.S. researchers demonstrated a correlation between the amount of trunk displacement after a significant isometric force was suddenly removed, and the risk of <a href="https://brookbushinstitute.com/article/knee" target="_blank" rel="noopener">knee</a> injury during a 3-year follow-up. Human movement professionals should consider screening for and addressing any noted impairments in core <a id="stability" data-tip="1191" target="_blank" href="/glossary-term/stability" class="glossary">stability</a> prior to the beginning of a season.
<a href="https://www.datocms-assets.com/25800/1646162623-kneeling-chop.jpeg"><img src="https://www.datocms-assets.com/25800/1646162623-kneeling-chop.jpeg"></a> Kneeling Chop. (Image: Courtesy of www.BrentBrookbush.com)

<table>
 <tbody>
 <tr>
 <td width="40%">Study Design</td>
 <td>Prospective cohort study</td>
 </tr>
 <tr>
 <td>Level of Evidence</td>
 <td>III Evidence from non-experimental observational studies, such as comparative studies, correlation studies, and case-control studies</td>
 </tr>
 <tr>
 <td>Participant Characteristics</td>
 <td>Demographics
 <ul>
 <li>Age (years +/- standard deviation):
 <ul>
 <li>19.4 +/- 1.0 (female)</li>
 <li>19.3 +/- 1.8 (male)</li>
 </ul>
 
 </li>
 <li>Gender: 140 female, 137 male</li>
 <li>Number of participants: 227</li>
 <li>Collegiate athletes participating in various sports</li>
 </ul>
 Inclusion Criteria:
 <ul>
 <li>No history of <a href="https://brookbushinstitute.com/article/knee" target="_blank" rel="noopener">knee</a> injury</li>
 </ul>
 Exclusion Criteria:
 <ul>
 <li>N/A</li>
 </ul>
 </td>
 </tr>
 <tr>
 <td>Methodology</td>
 <td>
 <ul>
 <li>Participants filled out a questionnaire with demographic data, athletic experience, and a history of any injury that prompted a visit to a physician</li>
 <li>Baseline trunk <a id="stability" data-tip="1191" target="_blank" href="/glossary-term/stability" class="glossary">stability</a> was tested</li>
 <li><a href="https://brookbushinstitute.com/article/knee" target="_blank" rel="noopener">Knee</a> injuries were tracked over a 3-year period</li>
 <li><a href="https://brookbushinstitute.com/article/knee" target="_blank" rel="noopener">Knee</a> injury was defined as &quot;ligament, meniscal or patellofemoral injury to the <a href="https://brookbushinstitute.com/article/knee" target="_blank" rel="noopener">knee</a> joint&quot;
 <ul>
 <li>All <a href="https://brookbushinstitute.com/article/knee" target="_blank" rel="noopener">knee</a> injuries were confirmed by magnetic resonance imaging (MRI)</li>
 <li>Fractures and contusions were not classified as <a href="https://brookbushinstitute.com/article/knee" target="_blank" rel="noopener">knee</a> injuries.</li>
 </ul>
 
 </li>
 <li>Core <a id="stability" data-tip="1191" target="_blank" href="/glossary-term/stability" class="glossary">stability</a> was evaluated by observing the response of the trunk to the sudden removal of an isometric force</li>
 <li>Testing was performed with the participant&apos;s pelvis and lower extremities stabilized in a wooden apparatus
 <ul>
 <li>Participants were semi-seated with their lumbar spine in a self determined &quot;comfortable position&quot;
 <ul>
 <li>The hips were in approximately 20&#xBA; of flexion, <a href="https://brookbushinstitute.com/article/knee" target="_blank" rel="noopener">knees</a> in approximately 90&#xBA; of flexion and the feet were free</li>
 </ul>
 
 </li>
 <li>Each participant wore a chest harness at the T5 spinal level that was connected via a pulley to an electromagnet and supplied the resistance for the isometric contraction for the trunk</li>
 <li>Resistance was &quot;30% of the maximal isometric trunk exertion for an average healthy man (108 N) or woman (72 N)&quot; as determined by a pilot study</li>
 </ul>
 
 </li>
 <li>Resistance was provided from 3 different directions:
 <ul>
 <li>Flexion (cable directed <a id="posterior" data-tip="1565" target="_blank" href="/glossary-term/posterior" class="glossary">posterior</a> from harness)</li>
 <li>Extension (cable <a id="anterior" data-tip="1566" target="_blank" href="/glossary-term/anterior" class="glossary">anterior</a> from harness)</li>
 <li>Lateral bending (cable right from harness)</li>
 </ul>
 
 </li>
 <li>Each participant performed 5 trials in which:
 <ul>
 <li>The electromagnet gradually increased direction-specific resistance</li>
 <li>Participants were instructed to maintain their position and were provided with a visual of the target resistance level</li>
 <li>The electromagnet was abruptly disengaged at random</li>
 </ul>
 <ul>
 <li>Trunk motion was recorded via sensor at T5 after the <a id="release" data-tip="1249" target="_blank" href="/glossary-term/release" class="glossary">release</a> of the isometric force
 <ul>
 <li>At 150 milliseconds (ms) after release</li>
 <li>At maximal trunk displacement</li>
 </ul>
 
 </li>
 </ul>
 
 </li>
 </ul>
 </td>
 </tr>
 <tr>
 <td>Data Collection and Analysis</td>
 <td>
 <ul>
 <li>A 3-factor analysis of variance and Tukey post hoc <a id="assessment" data-tip="1482" target="_blank" href="/glossary-term/assessment" class="glossary">test</a> identified significantly different values (force <a id="release" data-tip="1249" target="_blank" href="/glossary-term/release" class="glossary">release</a> direction, gender and history of injury) between injured and uninjured participants</li>
 <li>The variables were combined with demographic data to create a multiple logistic <a id="exercise-regression" data-tip="1179" target="_blank" href="/glossary-term/exercise-regression" class="glossary">regression</a> <a id="model" data-tip="1469" target="_blank" href="/glossary-term/model" class="glossary">model</a> that predicted <a href="https://brookbushinstitute.com/article/knee" target="_blank" rel="noopener">knee</a> injury in the sample as a whole, the type of <a href="https://brookbushinstitute.com/article/knee" target="_blank" rel="noopener">knee</a> injury and the difference between male and female participants
 <ul>
 <li>Data from a parallel study were also included, in which the Active Trunk Re-positioning (APR) <a id="assessment" data-tip="1482" target="_blank" href="/glossary-term/assessment" class="glossary">test</a> was used to <a id="assessment" data-tip="1486" target="_blank" href="/glossary-term/assessment" class="glossary">assess</a> trunk proprioception (2).
 <ul>
 <li>Each participant&apos;s trunk was slowly rotated from neutral to 20&#xBA; then slowly back to neutral.</li>
 <li>Participants pressed a switch to stop the return rotation when they believed they had returned to neutral.</li>
 <li>APR error was determined as the difference in degrees between neutral and where the apparatus was stopped.</li>
 </ul>
 
 </li>
 </ul>
 
 </li>
 </ul>
 <ul>
 <li>The <a id="exercise-regression" data-tip="1179" target="_blank" href="/glossary-term/exercise-regression" class="glossary">regression</a> was performed multiple times with minimally contributing variables removed each time until only variables with P&lt; 0.1 remained</li>
 <li>A binary logistic <a id="exercise-regression" data-tip="1179" target="_blank" href="/glossary-term/exercise-regression" class="glossary">regression</a> analysis was used to determine if the <a id="specificity" data-tip="1224" target="_blank" href="/glossary-term/specificity" class="glossary">specific</a> direction of trunk displacement was predictive of <a href="https://brookbushinstitute.com/article/knee" target="_blank" rel="noopener">knee</a> injury type and if there were differences between male and female participants</li>
 <li>A priori <a id="power" data-tip="1399" target="_blank" href="/glossary-term/power" class="glossary">power</a> analysis determined that 21 injuries over the 3-year period were needed to achieve a statistical <a id="power" data-tip="1399" target="_blank" href="/glossary-term/power" class="glossary">power</a> of 0.8</li>
 </ul>
 </td>
 </tr>
 <tr>
 <td>Outcome Measures</td>
 <td>
 <ul>
 <li>History of low back pain</li>
 <li><a href="https://brookbushinstitute.com/article/knee" target="_blank" rel="noopener">Knee</a> injuries and type over a 3-year period</li>
 <li>Trunk displacement at 150 milliseconds for flexion, extension and <a id="lateral" data-tip="1567" target="_blank" href="/glossary-term/lateral" class="glossary">lateral</a> displacement</li>
 <li>Maximal trunk displacement for flexion, extension and <a id="lateral" data-tip="1567" target="_blank" href="/glossary-term/lateral" class="glossary">lateral</a> displacement</li>
 <li>Active trunk re-positioning (APR) error</li>
 </ul>
 </td>
 </tr>
 <tr>
 <td>Results</td>
 <td>
 <ul>
 <li>During the 3-year follow-up period, 25 <a href="https://brookbushinstitute.com/article/knee" target="_blank" rel="noopener">knee</a> injuries occurred
 <ul>
 <li>11 female and 14 male participants reported injuries</li>
 <li>11 injuries were ligament injuries (5 female, 6 male)</li>
 <li>6 injuries were ACL ruptures (4 female, 2 male)</li>
 </ul>
 
 </li>
 <li>Trunk displacement at 150 milliseconds (ms) was greater in <a href="https://brookbushinstitute.com/article/knee" target="_blank" rel="noopener">knee</a>-injured than in uninjured athletes
 <ul>
 <li><a href="https://brookbushinstitute.com/article/knee" target="_blank" rel="noopener">Knee</a> injury P&lt;.05</li>
 <li>Ligament injury P&lt;.001</li>
 <li>ACL injury P&lt;.05</li>
 </ul>
 
 </li>
 <li>Maximal trunk displacement was significantly greater in <a href="https://brookbushinstitute.com/article/knee" target="_blank" rel="noopener">knee</a>-injured than in uninjured athletes
 <ul>
 <li><a href="https://brookbushinstitute.com/article/knee" target="_blank" rel="noopener">Knee</a> injury P&lt;.001</li>
 <li>Ligament injury P&lt;.05</li>
 <li>ACL injury P&lt;.001</li>
 <li>Uninjured P&lt;.05</li>
 </ul>
 
 </li>
 <li><a href="https://brookbushinstitute.com/article/knee" target="_blank" rel="noopener">Knee</a> ligament injured females demonstrated significantly greater maximal trunk displacement than uninjured females (P=.005)
 <ul>
 <li>No significant differences in maximal trunk displacement were noted between injured and uninjured males</li>
 </ul>
 
 </li>
 <li>The multiple logistic <a id="exercise-regression" data-tip="1179" target="_blank" href="/glossary-term/exercise-regression" class="glossary">regression</a> <a id="model" data-tip="1469" target="_blank" href="/glossary-term/model" class="glossary">model</a> determined:
 <ul>
 <li>Trunk displacement in all 3 directions at 150 ms (maximal trunk displacement variable eliminated because it correlated with displacement at 150 ms), absolute error in the APR <a id="assessment" data-tip="1482" target="_blank" href="/glossary-term/assessment" class="glossary">test</a> and the history of low back pain predicted <a href="https://brookbushinstitute.com/article/knee" target="_blank" rel="noopener">knee</a> injury with 83% <a id="sensitivity" data-tip="1226" target="_blank" href="/glossary-term/sensitivity" class="glossary">sensitivity</a> and 63% <a id="specificity" data-tip="1223" target="_blank" href="/glossary-term/specificity" class="glossary">specificity</a> (P&lt;.0001).</li>
 <li>Trunk displacement at 150 ms and a history of low back pain predicted ligament injury with 91% <a id="sensitivity" data-tip="1226" target="_blank" href="/glossary-term/sensitivity" class="glossary">sensitivity</a> and 68% <a id="specificity" data-tip="1223" target="_blank" href="/glossary-term/specificity" class="glossary">specificity</a> (P=.001)</li>
 <li>Trunk displacement in all directions at 150 ms was the sole predictor of ACL injury with 83% <a id="sensitivity" data-tip="1226" target="_blank" href="/glossary-term/sensitivity" class="glossary">sensitivity</a> and 76% <a id="specificity" data-tip="1223" target="_blank" href="/glossary-term/specificity" class="glossary">specificity</a> (P=.002)</li>
 <li>The strongest predictor of injuries in females were the trunk displacement variables (85% accurate for <a href="https://brookbushinstitute.com/article/knee" target="_blank" rel="noopener">knee</a> injuries, 91% for ligament, 89% for ACL)
 <ul>
 <li>Active Proprioceptive Re-positioning (APR) error and history of low back pain were also predictors</li>
 </ul>
 
 </li>
 <li>The strongest predictor of injuries in male participants was a history of low back pain (P=.015).</li>
 </ul>
 
 </li>
 <li>The binary logistic <a id="exercise-regression" data-tip="1179" target="_blank" href="/glossary-term/exercise-regression" class="glossary">regression</a> determined:
 <ul>
 <li>Excessive <a id="lateral" data-tip="1567" target="_blank" href="/glossary-term/lateral" class="glossary">lateral</a> displacement was the strongest predictor of <a href="https://brookbushinstitute.com/article/knee" target="_blank" rel="noopener">knee</a>, ligament and ACL injuries in all athletes
 <ul>
 <li>It was a significant predictor of ligament injury in female athletes (100% <a id="sensitivity" data-tip="1226" target="_blank" href="/glossary-term/sensitivity" class="glossary">sensitivity</a>, 72% <a id="specificity" data-tip="1223" target="_blank" href="/glossary-term/specificity" class="glossary">specificity</a>, P=.024)</li>
 <li>It did not predict injury in male athletes</li>
 </ul>
 
 </li>
 </ul>
 
 </li>
 </ul>
 </td>
 </tr>
 <tr>
 <td>Our Conclusions</td>
 <td>The results of this study demonstrate that greater trunk displacement following the sudden removal of a significant isometric force is correlated with increased risk of <a href="https://brookbushinstitute.com/article/knee" target="_blank" rel="noopener">knee</a> injury. This may imply that descriptions of <a href="https://brookbushinstitute.com/article/lower-leg-dysfunction" target="_blank" rel="noopener">Lower Extremity Dysfunction (LED)</a> should include re-activity as well as changes in alignment.</td>
 </tr>
 <tr>
 <td>Researchers&apos; Conclusions
 
 </td>
 <td>Athletes with a history of low back pain, increased trunk displacement following release of an isometric force and errors in trunk APR demonstrated an increased risk of <a href="https://brookbushinstitute.com/article/knee" target="_blank" rel="noopener">knee</a> injury. Males and females exhibited different predisposing factors for injury. The implementation of interventions that incorporate core stability training, including proprioceptive exercise, perturbation and correction of body sway, has the potential to reduce <a href="https://brookbushinstitute.com/article/knee" target="_blank" rel="noopener">knee</a>, ligament and ACL injury risk in male and female athletes.</td>
 </tr>
 </tbody>
</table>
<a href="https://www.datocms-assets.com/25800/1646162676-kill-the-trainer.jpeg"><img src="https://www.datocms-assets.com/25800/1646162676-kill-the-trainer.jpeg"></a> Single-Leg <a id="balance" data-tip="1190" target="_blank" href="/glossary-term/balance" class="glossary">Balance</a> Reactive Drill (Kill the Trainer). (Image: Courtesy of www.BrentBrookbush.com)

The relationship between core <a id="stability" data-tip="1191" target="_blank" href="/glossary-term/stability" class="glossary">stability</a> and lower extremity (LE) injury highlights the interdependence of the trunk and LE (5-8). Previous research has shown a correlation between decreased neuromuscular control of the core, hamstrings, and <a href="https://brookbushinstitute.com/article/ankle-joint-talocrural-subtalor-tibiofibular-joints" target="_blank" rel="noopener">ankle</a> injuries (9-11). Unique to this study, the researchers prospectively investigated an athlete&apos;s trunk displacement following the sudden removal of a significant isometric force and correlation with future <a href="https://brookbushinstitute.com/article/knee" target="_blank" rel="noopener">knee</a> injury. This study demonstrates that decreased core reactivity is correlated with future <a href="https://brookbushinstitute.com/article/knee" target="_blank" rel="noopener">knee</a> injury.

The findings of this study demonstrate a correlation between decreased core reactivity and increased risk of future <a href="https://brookbushinstitute.com/article/knee" target="_blank" rel="noopener">knee</a> injury in athletes. This may imply interdependence between the trunk and leg, and suggest that <a id="assessment" data-tip="1478" target="_blank" href="/glossary-term/assessment" class="glossary">assessment</a> of <a href="https://brookbushinstitute.com/article/lower-leg-dysfunction" target="_blank" rel="noopener">Lower Extremity Dysfunction (LED)</a> should include <a id="assessment" data-tip="1480" target="_blank" href="/glossary-term/assessment" class="glossary">assessments</a> for <a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">hip</a>, <a href="https://brookbushinstitute.com/article/knee" target="_blank" rel="noopener">knee</a>, and <a href="https://brookbushinstitute.com/article/ankle-joint-talocrural-subtalor-tibiofibular-joints" target="_blank" rel="noopener">ankle</a> impairments and trunk <a href="https://brookbushinstitute.com/glossary/compensation-pattern/" target="_blank" rel="noopener">compensation patterns</a>. Further, human movement professionals should have a repertoire of techniques for addressing decreased core reactivity, and potentially <a id="integration" data-tip="1473" target="_blank" href="/glossary-term/integration" class="glossary">integrated</a> techniques for addressing coordination between the trunk/pelvis and lower extremity.
This study had many methodological strengths, including:
<ul>
 <li>Prospective studies are relatively rare in human movement science. This study followed athletes for 3 years after testing and provides evidence that impairment may be a cause, and/or predictive of injury.</li>
 <li>The researchers tested the trunk from multiple directions, which mimicked the potential variability in <a id="posture" data-tip="1659" target="_blank" href="/glossary-term/posture" class="glossary">postural</a> perturbations during sport activities.</li>
 <li>An athlete&apos;s ability to generate a trunk stabilizing motor response (sudden trunk unloading <a id="assessment" data-tip="1482" target="_blank" href="/glossary-term/assessment" class="glossary">test</a>) and his or her ability to accurately perceive the position of their trunk in space (Active Trunk Repositioning <a id="assessment" data-tip="1482" target="_blank" href="/glossary-term/assessment" class="glossary">test</a>) were included in the <a id="exercise-regression" data-tip="1179" target="_blank" href="/glossary-term/exercise-regression" class="glossary">regression</a> <a id="model" data-tip="1471" target="_blank" href="/glossary-term/model" class="glossary">models</a> in this study. Both accurate sensory input and efficient motor output are needed for <a id="optimal" data-tip="1571" target="_blank" href="/glossary-term/optimal" class="glossary">optimal</a> dynamic <a id="stability" data-tip="1191" target="_blank" href="/glossary-term/stability" class="glossary">stability</a>.</li>
 <li>Statistical analysis was performed on male and female participants together and separately. This allowed for observation of whether different variables predicted injury in different sexes.</li>
 <li>The researchers performed an a priori <a id="power" data-tip="1399" target="_blank" href="/glossary-term/power" class="glossary">power</a> analysis based on pilot testing to achieve a statistical <a id="power" data-tip="1399" target="_blank" href="/glossary-term/power" class="glossary">power</a> of 0.80, and exceeded the number of needed injuries in the study.</li>
</ul>
Weaknesses that should be noted prior to clinical <a href="https://brookbushinstitute.com/glossary/integration/" target="_blank" rel="noopener">integration</a> of the findings include:
<ul>
 <li>The participants&apos; baseline injury history was not reported. Such data would have provided more information about the sample prior to observation.</li>
 <li>A significant amount of equipment was required to position participants and record perturbations. Future research should consider the <a id="predictive-values" data-tip="1738" target="_blank" href="/glossary-term/predictive-values" class="glossary">predictive value</a> of core <a id="stability" data-tip="1191" target="_blank" href="/glossary-term/stability" class="glossary">stability</a> &quot;field tests&quot; that can be performed with minimal or no equipment.</li>
 <li>A functional athletic position was not tested. While the authors noted this was done to avoid compensation by any lower extremity muscles, this limits generalization of the findings to functional activity.</li>
 <li>A young, athletic population was studied. Findings may not generalize to older or more sedentary populations.</li>
</ul>

The Brookbush Institute (BI) has developed 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, such as the <a href="https://brookbushinstitute.com/article/lower-leg-dysfunction" target="_blank" rel="noopener">Lower Extremity Dysfunction (LED)</a>, to aid human movement professionals in selecting <a id="optimal" data-tip="1571" target="_blank" href="/glossary-term/optimal" class="glossary">optimal</a> <a id="assessment" data-tip="1480" target="_blank" href="/glossary-term/assessment" class="glossary">assessments</a>, manual interventions, and exercise. This study demonstrates that decreased core reactivity is correlated with an increased risk of <a href="https://brookbushinstitute.com/article/knee" target="_blank" rel="noopener">knee</a> injury in athletes. The findings of this study were <a id="integration" data-tip="1473" target="_blank" href="/glossary-term/integration" class="glossary">integrated</a> with additional studies demonstrating a correlation between trunk <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> weakness, <a id="stability" data-tip="1191" target="_blank" href="/glossary-term/stability" class="glossary">stability</a>, and <a href="https://brookbushinstitute.com/article/lower-leg-dysfunction" target="_blank" rel="noopener">Lower Extremity Dysfunction (LED)</a>. In a comprehensive treatment and/or training program, the BI recommends including core stability/reactivity exercises to ensure <a id="integration" data-tip="1472" target="_blank" href="/glossary-term/integration" class="glossary">integration</a> with the affected/addressed segment. The BI continues to pursue <a href="https://brookbushinstitute.com/glossary/optimal/" target="_blank" rel="noopener">optimal</a> practice by refining <a href="https://brookbushinstitute.com/article/introduction-to-postural-dysfunction-and-movement-impairment" target="_blank" rel="noopener">predictive </a><a id="model" data-tip="1471" target="_blank" href="/glossary-term/model" class="glossary">models</a> of <a id="posture" data-tip="1659" target="_blank" href="/glossary-term/posture" class="glossary">postural</a> dysfunction&#xA0;and looks forward to the <a id="integration" data-tip="1472" target="_blank" href="/glossary-term/integration" class="glossary">integration</a> of more insightful studies like the one reviewed here.

TVA and Gluteus Maximus Activation and Progressions
<iframe src="https://player.vimeo.com/video/82877282" frameborder="0" allowfullscreen="allowfullscreen"></iframe>
Quadruped Crawl
<iframe src="https://player.vimeo.com/video/133934741" frameborder="0" allowfullscreen="allowfullscreen"></iframe>
Quadruped Crawl 2
<iframe src="https://player.vimeo.com/video/263787607" frameborder="0" allowfullscreen="allowfullscreen"></iframe>
Resisted Quadruped Crawl
<iframe src="https://player.vimeo.com/video/306488004" frameborder="0" allowfullscreen="allowfullscreen"></iframe>
Kneeling Chop Pattern
<iframe src="https://player.vimeo.com/video/267500518" frameborder="0" allowfullscreen="allowfullscreen"></iframe>
Single Leg Standing Chop Pattern
<iframe src="https://player.vimeo.com/video/267503968" frameborder="0" allowfullscreen="allowfullscreen"></iframe>
Crunch and Catch

<ol>
 <li>Ingram, J. G., Fields, S. K., Yard, E. E., and Comstock, R. D. (2008). Epidemiology of knee injuries among boys and girls in US high school athletics. The American journal of sports medicine, 36(6), 1116-1122.</li>
 <li>Powell, J. W., &amp; Barber-Foss, K. D. (1999). Injury patterns in selected high school sports: a review of the 1995-1997 seasons. Journal of athletic training, 34(3), 277.</li>
 <li>Hewett, T. E., Paterno, M. V., &amp; Myer, G. D. (2002). Strategies for enhancing proprioception and neuromuscular control of the knee. Clinical Orthopaedics and Related Research&reg;, 402, 76-94.</li>
 <li>Hewett, T. E., Zazulak, B. T., Myer, G. D., &amp; Ford, K. R. (2005). A review of electromyographic activation levels, timing differences, and increased anterior cruciate ligament injury incidence in female athletes. British journal of sports medicine, 39(6), 347-350.</li>
 <li>Zazulak, B. T., Hewett, T. E., Reeves, N. P., Goldberg, B., and Cholewicki, J. (2007). The effects of core proprioception on knee injury: a prospective biomechanical-epidemiological study. The American journal of sports medicine.</li>
 <li>Heiderscheit, B. C. (2010). Lower extremity injuries: is it just about hip strength? journal of orthopaedic &amp; sports physical therapy, 40(2), 39-41.</li>
 <li>Leetun, D. T., Ireland, M. L., Willson, J. D., Ballantyne, B. T., &amp; Davis, I. M. (2004). Core stability measures as risk factors for lower extremity injury in athletes. Medicine &amp; Science in Sports &amp; Exercise, 36(6), 926-934.</li>
 <li><a href="https://brookbushinstitute.com/article/role-of-the-diaphragm-in-stabilization" target="_blank" rel="noopener">Hodges, P. W., Butler, J. E., McKenzie, D. K., and Gandevia, S. C. (1997). Contraction of the human diaphragm during rapid postural adjustments. The Journal of physiology, 505(Pt 2), 539-548.</a></li>
 <li>Cholewicki, J., Silfies, S. P., Shah, R. A., Greene, H. S., Reeves, N. P., Alvi, K., &amp; Goldberg, B. (2005). Delayed trunk muscle reflex responses increase the risk of low back injuries. Spine, 30(23), 2614-2620.</li>
 <li>Devlin, L. (2000). Recurrent posterior thigh symptoms detrimental to performance in rugby union. Sports Medicine, 29(4), 273-287.</li>
 <li>Beynnon, B., Vacek, P. M., Abate III, J. A., Murphy, D., &amp; Paller, D. (2006, July). A prospective study of risk factors for first time ankle inversion ankle ligament trauma. In 32nd annual meeting of the American Orthopaedic Society for Sports Medicine</li>
</ol>

The Impact of Hip Strength on Trunk and Lower Extremity Coordination During Walking and Hopping

Original Citation: Smith, J. A., Popovich Jr, J. M., &amp; Kulig, K. (2014). The influence of hip strength on lower-limb, pelvis, and trunk kinematics and coordination patterns during walking and hopping in healthy women. journal of orthopaedic &amp; sports physical therapy, 44(7), 525-531. - <a href="https://www.jospt.org/doi/pdf/10.2519/jospt.2014.5028" target="_blank" rel="noopener">ARTICLE</a>
A growing body of research is demonstrating that impaired muscular control of the <a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">hip</a>, pelvis, and trunk affects lower extremity (LE) kinematics and kinetics in multiple planes (1-5). This 2014 study by U.S. researchers demonstrated a correlation between <a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">hip</a> weakness, increased frontal plane trunk motion, and significantly altered LE, trunk, and pelvis coordination during weight-bearing tasks. Human movement professionals should consider assessing and addressing any noted weakness of <a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">hip</a> abductors and extensors in individuals exhibiting LE dysfunction.
<a href="https://brookbush.s3.us-east-2.amazonaws.com/wordpress/wp-content/uploads/2014/12/1347722902.png" target="_blank" rel="noopener"><img src="https://brookbush.s3.us-east-2.amazonaws.com/wordpress/wp-content/uploads/2014/12/1347722902.png" alt></a>
Compensation of the trunk in response to weakness in hip extensors/abductors. (Image: Courtesy of http://www.thestudentphysicaltherapist.com/online-courses/online-courses/trendelenburg-test)

<table>
 <tbody>
 <tr>
 <td width="40%">Study Design</td>
 <td>Cross-sectional correlation study</td>
 </tr>
 <tr>
 <td>Level of Evidence</td>
 <td>III Evidence from non-experimental descriptive studies, such as comparative studies, correlation studies, and case-control studies</td>
 </tr>
 <tr>
 <td>Participant Characteristics</td>
 <td>Demographics
 <ul>
 <li>Age:
 <ul>
 <li>Strong Group (SG): 23.44 &#xB1; 3.54 years</li>
 <li>Weak Group (WG): 24.10 &#xB1; 3.31 years</li>
 </ul>
 </li>
 <li>Gender: female</li>
 <li>Characteristics:
 <ul>
 <li>Height:
 <ul>
 <li>SG: 1.66 &#xB1; 0.06 meters</li>
 <li>WG: 1.67 &#xB1; 0.05 meters</li>
 </ul>
 </li>
 <li>Weight:
 <ul>
 <li>SG: 58.57 &#xB1; 5.32 kg</li>
 <li>WG: 61.16 &#xB1; 6.49 kg</li>
 </ul>
 </li>
 </ul>
 </li>
 <li>Number of participants: 19 (SG= 10, WG=9)</li>
 </ul>
 Inclusion Criteria:
 <ul>
 <li>Participants were assigned to either the SG or WG based on normalized peak <a id="torque" data-tip="1294" target="_blank" href="/glossary-term/torque" class="glossary">torque</a> if both <a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">hip</a> abduction (ABD) and extension (EXT) in their dominant limb fell outside of a 95% confidence interval.</li>
 </ul>
 Exclusion Criteria:
 <ul>
 <li>History of injury or surgery in the lower extremities and spine.</li>
 <li>Presence of any other medical condition that could affect physical activity.</li>
 </ul>
 </td>
 </tr>
 <tr>
 <td>Methodology</td>
 <td>
 <ul>
 <li>150 young, healthy females underwent strength testing for peak isometric <a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">hip</a> EXT and ABD torques.</li>
 <li>Participants whose normalized peak <a id="torque" data-tip="1294" target="_blank" href="/glossary-term/torque" class="glossary">torque</a> of both <a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">hip</a> abduction (ABD) and extension (EXT) in their dominant limb fell outside of a 95% confidence interval were assigned into either the SG (n=10) or WG (n=9).
 <ul>
 <li>The confidence interval was calculated from the distribution of ABD and EXT <a id="torque" data-tip="1294" target="_blank" href="/glossary-term/torque" class="glossary">torque</a> values from a database of the first 30 female participants tested in the study.</li>
 </ul>
 </li>
 <li>Participants in the SG and WG were assessed for:
 <ul>
 <li>Kinematics of the <a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">hip</a>, <a href="https://brookbushinstitute.com/article/knee" target="_blank" rel="noopener">knee</a>, pelvis and trunk during the stance phase of walking and rate-controlled hopping.</li>
 <li><a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">Hip</a>/<a href="https://brookbushinstitute.com/article/knee" target="_blank" rel="noopener">knee</a> and pelvis/trunk coordination were calculated using the vector coding technique.</li>
 </ul>
 </li>
 </ul>
 </td>
 </tr>
 <tr>
 <td>Data Collection and Analysis</td>
 <td>Data Collection
 <ul>
 <li>Kinematic data were collected using a 10-camera 3-D motion-capture system at 250 Hz.
 <ul>
 <li>Placement of retroreflective markers:
 <ul>
 <li>Bilateral <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 spines, iliac crests, and L5-S1 interspinous space to track motion of the pelvis.</li>
 <li>Spinous process of T3 to track motion of the trunk.</li>
 <li>Bilateral heel counter of the shoes, shanks, and <a id="lateral" data-tip="1567" target="_blank" href="/glossary-term/lateral" class="glossary">lateral</a> thighs to track the segmental motion of the lower extremities (LE).</li>
 </ul>
 </li>
 </ul>
 </li>
 </ul>
 Data Analysis
 <ul>
 <li>2-way repeated-measures analyses of variance were used to examine the main effects of group (between-subjects, SG and WG) and interaction effects of the group by task (within-subject, walk and hop) on the <a id="dependent-variable" data-tip="1438" target="_blank" href="/glossary-term/dependent-variable" class="glossary">dependent variables</a>.</li>
 <li>Post hoc comparisons on significant group effects were calculated using t-tests&#xA0;for independent samples.
 <ul>
 <li>A Bonferroni correction was used for multiple comparisons.</li>
 <li>The alpha level for each pairwise comparison was multiplied by the number of comparisons for that variable.</li>
 </ul>
 </li>
 <li>Significance was set at p&#x2264;0.05.</li>
 <li>Effect sizes for pairwise comparisons were calculated using Cohen&apos;s d.</li>
 </ul>
 </td>
 </tr>
 <tr>
 <td>Outcome Measures</td>
 <td>
 <ul>
 <li>Peak <a id="torque" data-tip="1294" target="_blank" href="/glossary-term/torque" class="glossary">torque</a> isometric <a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">hip</a> ABD strength for dominant and non-dominant LE.</li>
 <li>Peak <a id="torque" data-tip="1294" target="_blank" href="/glossary-term/torque" class="glossary">torque</a> isometric <a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">hip</a> EXT strength for dominant and non-dominant LE.</li>
 <li>Self-selected walking speed.</li>
 <li>Single-leg hopping at a predetermined pace.</li>
 <li>Peak angles of the hip and knee joints in the frontal and transverse planes.</li>
 <li>Peak angles of the pelvis and trunk in the frontal and transverse planes.</li>
 <li>Coordination patterns between LE joints.</li>
 <li>Coordination patterns between the trunk and pelvis segments.</li>
 </ul>
 </td>
 </tr>
 <tr>
 <td>Results</td>
 <td>
 <ul>
 <li>There were no significant differences in age, height or weight between the groups.</li>
 </ul>
 Strength and Walking Speed
 <ul>
 <li>The SG demonstrated significantly greater <a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">hip</a> ABD and EXT strength on both LE as compared to the WG.</li>
 <li>Mean self-selected walking speed was not significantly different between groups.</li>
 </ul>
 Kinematics
 <ul>
 <li>The WG demonstrated a significantly greater change in peak trunk motion during hopping compared with walking than the SG (F = 8.657, P = 0.009).</li>
 <li>There was no significant difference in peak trunk motion between groups during walking (WG 2.5&#xB0; &#xB1; 1.6&#xB0;, SG 1.3&#xB0; &#xB1; 1.5&#xB0;, P = o.234).</li>
 <li>The WG demonstrated a significantly greater trunk <a id="lateral" data-tip="1567" target="_blank" href="/glossary-term/lateral" class="glossary">lateral</a> bend toward the stance limb during hopping compared to the SG (WG 7.9&#xB0; &#xB1; 2.1&#xB0;, SG 4.1&#xB0; &#xB1; 2.0&#xB0;, P = 0.002; d = 1.88).</li>
 <li>There was a trend toward the WG demonstrating a greater <a id="ipsilateral" data-tip="1550" target="_blank" href="/glossary-term/ipsilateral" class="glossary">ipsilateral</a> frontal plane pelvic tilt than the SG for both walking and hopping.
 <ul>
 <li>Walking: WG 2.0&#xB0; &#xB1; 1.3&#xB0;, SG 2.5&#xB0; &#xB1; 1.1&#xB0;, P = 0.756</li>
 <li>Hopping: WG 11.0&#xB0; &#xB1; 2.1&#xB0;, SG 9.0&#xB0; &#xB1; 2.0&#xB0;, P = 0.108</li>
 </ul>
 
 </li>
 </ul>
 Coordination Patterns
 <ul>
 <li>The WG utilized less inphase coordination between the hip and knee in the transverse plane during walking (WG 22.4% &#xB1; 6.4%, SG 29.4% &#xB1; 2.7%, P = 0.036, d = 1.45).</li>
 <li>The WG utilized greater hip motion in the transverse plane (<a id="proximal" data-tip="1564" target="_blank" href="/glossary-term/proximal" class="glossary">proximal</a> phase) than SG (WG 23.2% &#xB1; 6.1%; SG 15.7% &#xB1; 2.0%, P = 0.036, d = 1.70).</li>
 <li>The WG had significantly greater antiphase coordination between the hip and knee in the transverse plane during hopping (WG 30.2% &#xB1; 7.1%; SG 17.0% &#xB1; 10.4%, P = 0.03, d = 1.47).</li>
 <li>There was a trend toward the WG utilizing more inphase coordination between the trunk and pelvis in the frontal plane than the SG, however, this did not achieve statistical significance (WG 10.0% &#xB1; 5.3%, SG 5.4% &#xB1; 1.8%, P = 0.066, d = 1.19).</li>
 <li>The WG demonstrated less inphase coordination between the pelvis and trunk in the transverse plane during hopping (WG 33.0% &#xB1; 18.5%; SG 47.90% &#xB1; 8.72%, P = 0.028).</li>
 </ul>
 </td>
 </tr>
 <tr>
 <td>Our Conclusions</td>
 <td>The results of this study demonstrate that increased frontal plane trunk motion during hopping, and significantly altered LE and trunk/pelvis coordination during walking and hopping are associated with hip weakness. This may imply that compensatory changes may be indicative of hip weakness. These compensatory changes are similar to those described in the Brookbush Institute&#x2019;s model of <a href="https://brookbushinstitute.com/article/lower-leg-dysfunction" target="_blank" rel="noopener">Lower Extremity Dysfunction (LED)</a>.</td>
 </tr>
 <tr>
 <td>Researchers&apos; Conclusions
 
 </td>
 <td>Young, healthy women at either end of the spectrum of <a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">hip</a> ABD and EXT strength demonstrated significantly different coordination patterns between the LE and the trunk/pelvis. While kinematics of the <a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">hip</a> and <a href="https://brookbushinstitute.com/article/knee" target="_blank" rel="noopener">knee</a> were not significant between the SG and WG, significant differences were noted at the trunk/pelvis during walking and hopping tasks. This suggests that women with weak <a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">hip</a> musculature use compensation strategies at the trunk/pelvis during submaximal motor tasks.</td>
 </tr>
 </tbody>
</table>
<a href="https://brookbush.s3.us-east-2.amazonaws.com/wordpress/wp-content/uploads/2016/06/Gluteus-Medius-MMT.png" target="_blank" rel="noopener"><img src="https://brookbush.s3.us-east-2.amazonaws.com/wordpress/wp-content/uploads/2016/06/Gluteus-Medius-MMT-1024x545.png" alt="Dr. Brent Brookbush tests the Gluteus Medius using a Manual Muscle Test modified for an active population"></a> Hip abduction with manual resistance. (Image: Courtesy of www.BrentBrookbush.com)

The relationship between lower extremity (LE) dysfunction and <a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">hip</a> abductor (ABD) and extensor (EXT) <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> weakness highlights the interdependence of the trunk and LE musculature (1-5). Previous research has shown a correlation between <a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">hip</a> strength and single-joint LE kinematics but did not investigate the influence on trunk motion (6-9). Unique to this study, the researchers investigated the angular motion and coordination patterns of the trunk, pelvis, and LE in healthy, young females. This study demonstrates that a correlation exists between <a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">hip</a> weakness, frontal plane trunk motion, and coordination of the LE and trunk/pelvis during weight-bearing tasks.

The strongest correlation found in this study was between <a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">hip</a> weakness and altered LE and trunk/pelvis coordination during dynamic weight-bearing tasks. This may imply interdependence between the trunk and LE muscles and suggest that <a id="assessment" data-tip="1478" target="_blank" href="/glossary-term/assessment" class="glossary">assessment</a> of <a href="https://brookbushinstitute.com/article/lower-leg-dysfunction" target="_blank" rel="noopener">Lower Extremity Dysfunction (LED)</a> should include <a id="assessment" data-tip="1480" target="_blank" href="/glossary-term/assessment" class="glossary">assessments</a> for <a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">hip</a> impairments and trunk compensation patterns. Further, human movement professionals should have a repertoire of techniques for addressing hip <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> weakness (<a href="https://brookbushinstitute.com/article/gluteus-medius-activation-progression" target="_blank" rel="noopener">gluteus medius activation</a> and <a href="https://brookbushinstitute.com/article/gluteus-maximus-activation" target="_blank" rel="noopener">gluteus maximus activation</a>), and potentially <a id="integration" data-tip="1473" target="_blank" href="/glossary-term/integration" class="glossary">integrated</a> techniques for addressing coordination between the trunk/pelvis and lower extremity.
This study had many methodological strengths, including:
<ul>
 <li>The researchers used <a id="reliability" data-tip="1795" target="_blank" href="/glossary-term/reliability" class="glossary">reliable</a> <a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">hip</a> ABD and EXT strength testing methods as demonstrated by a previous study (10), and the use of a dynamometer during testing provided objective data.</li>
 <li>The vector coding technique utilized in this study for coordination analysis has been shown to be more appropriate for oscillatory motor tasks, such as hopping (11).</li>
 <li>The hopping rate was controlled during testing using a metronome to control for extraneous variables and to induce a greater demand on the <a href="https://brookbushinstitute.com/article/knee" target="_blank" rel="noopener">knee</a> than self-selected hopping (12).</li>
 <li>The researchers performed an a priori <a id="power" data-tip="1399" target="_blank" href="/glossary-term/power" class="glossary">power</a> analysis based on previous studies on drop jump tasks to achieve a statistical <a id="power" data-tip="1399" target="_blank" href="/glossary-term/power" class="glossary">power</a> of 0.80, and exceeded the number of needed participants in the study.</li>
</ul>
Weaknesses that should be noted prior to clinical <a href="https://brookbushinstitute.com/glossary/integration/" target="_blank" rel="noopener">integration</a> of the findings include:
<ul>
 <li>This study examined females with strong and weak <a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">hip</a> <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> strength, which limits the generalizability of the results to those with less extreme <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> performance.</li>
 <li>This study examined the strength of the <a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">hip</a> abductor and extensor musculature. Future research may also consider targeted strength testing of the <a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">hip</a> external rotator muscles.</li>
 <li>The researchers did not control for physical activity levels in the participants, which could have impacted the results.</li>
 <li>The researchers did not examine the non-dominant LE, which could have provided additional data and improved the results.</li>
</ul>

The Brookbush Institute (BI) has developed 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, such as the predictive <a id="model" data-tip="1469" target="_blank" href="/glossary-term/model" class="glossary">model</a> of <a href="https://brookbushinstitute.com/article/lower-leg-dysfunction" target="_blank" rel="noopener">Lower Extremity Dysfunction (LED)</a>, to aid human movement professionals in the <a id="optimal" data-tip="1571" target="_blank" href="/glossary-term/optimal" class="glossary">optimal</a> selection of <a id="assessment" data-tip="1480" target="_blank" href="/glossary-term/assessment" class="glossary">assessments</a>, manual interventions, and exercise. This study demonstrates that increased frontal plane trunk motion and significantly altered LE and trunk/pelvis coordination during weight-bearing tasks are correlated with <a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">hip</a> <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> weakness in healthy, young females. These findings were <a id="integration" data-tip="1473" target="_blank" href="/glossary-term/integration" class="glossary">integrated</a> with similar studies demonstrating a correlation between <a href="https://brookbushinstitute.com/article/hip-joint" target="_blank" rel="noopener">hip</a> <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> weakness and LED and further consideration was given to the effect on trunk and pelvis motion in the <a id="model" data-tip="1469" target="_blank" href="/glossary-term/model" class="glossary">model</a> of <a href="https://brookbushinstitute.com/article/lower-leg-dysfunction" target="_blank" rel="noopener">Lower Extremity Dysfunction (LED)</a>. The BI will continue to pursue <a href="https://brookbushinstitute.com/glossary/optimal/" target="_blank" rel="noopener">optimal</a> practice by aggregating the results of all available evidence.

Quadratus Lumborum SA Static <a id="release" data-tip="1249" target="_blank" href="/glossary-term/release" class="glossary">Release</a> and Stretch
<iframe src="//player.vimeo.com/video/104193121?title=0&amp;byline=0&amp;portrait=0" frameborder="0" allowfullscreen="allowfullscreen"></iframe>
Kneeling Hip Flexor (TFL) Stretch:
<iframe src="https://player.vimeo.com/video/82860782" frameborder="0" allowfullscreen="allowfullscreen"></iframe>
Gluteus Medius Isolated Activation
<iframe src="//player.vimeo.com/video/82856186?title=0&amp;byline=0&amp;portrait=0" frameborder="0" allowfullscreen="allowfullscreen"></iframe>
Gluteus Medius <a id="exercise-progression" data-tip="1182" target="_blank" href="/glossary-term/exercise-progression" class="glossary">Progressions</a> (Activation Circuit)
<iframe src="//player.vimeo.com/video/82857653?title=0&amp;byline=0&amp;portrait=0" frameborder="0" allowfullscreen="allowfullscreen"></iframe>
Side Stepping:
<iframe src="//player.vimeo.com/video/76716671?title=0&amp;byline=0&amp;portrait=0" frameborder="0" allowfullscreen="allowfullscreen"></iframe>
Side Stepping Progressions:
<iframe src="//player.vimeo.com/video/76716828?title=0&amp;byline=0&amp;portrait=0" frameborder="0" allowfullscreen="allowfullscreen"></iframe>

<ol>
 <li>Heiderscheit, B. C. (2010). Lower extremity injuries: is it just about hip strength? journal of orthopaedic &amp; sports physical therapy, 40(2), 39-41.</li>
 <li>Powers, C. M. (2010). The influence of abnormal hip mechanics on knee injury: a biomechanical perspective. journal of orthopaedic &amp; sports physical therapy, 40(2), 42-51.</li>
 <li>Leetun, D. T., Ireland, M. L., Willson, J. D., Ballantyne, B. T., &amp; Davis, I. M. (2004). Core stability measures as risk factors for lower extremity injury in athletes. Medicine &amp; Science in Sports &amp; Exercise, 36(6), 926-934.</li>
 <li>Niemuth, P. E., Johnson, R. J., Myers, M. J., &amp; Thieman, T. J. (2005). Hip muscle weakness and overuse injuries in recreational runners. Clinical Journal of Sport Medicine, 15(1), 14-21.</li>
 <li>Reiman, M. P., Bolgla, L. A., &amp; Lorenz, D. (2009). Hip function&rsquo;s influence on knee dysfunction: a proximal link to a distal problem. Journal of Sport Rehabilitation, 18(1), 33-46.</li>
 <li>Cashman, G. E. (2012). The effect of weak hip abductors or external rotators on knee valgus kinematics in healthy subjects: a systematic review. Journal of sport rehabilitation, 21(3), 273-284.</li>
 <li>Hollman, J. H., Hohl, J. M., Kraft, J. L., Strauss, J. D., &amp; Traver, K. J. (2012). Effects of hip extensor fatigue on lower extremity kinematics during a jump-landing task in women: a controlled laboratory study. Clinical Biomechanics, 27(9), 903-909.</li>
 <li>Lawrence III, R. K., Kernozek, T. W., Miller, E. J., Torry, M. R., &amp; Reuteman, P. (2008). Influences of hip external rotation strength on knee mechanics during single-leg drop landings in females. Clinical biomechanics, 23(6), 806-813.</li>
 <li>Powers, C. M. (2010). The influence of abnormal hip mechanics on knee injury: a biomechanical perspective. journal of orthopaedic &amp; sports physical therapy, 40(2), 42-51.</li>
 <li>Latash, M. L., &amp; Anson, J. G. (2006). Synergies in health and disease: relations to adaptive changes in motor coordination. Physical therapy, 86(8), 1151-1160.</li>
 <li>Popovich, J. J., &amp; Kulig, K. (2012). Lumbopelvic landing kinematics and EMG in women with contrasting hip strength. Medicine and science in sports and exercise, 44(1), 146-153.</li>
 <li>Souza, R. B., Arya, S., Pollard, C. D., Salem, G., &amp; Kulig, K. (2010). Patellar tendinopathy alters the distribution of lower extremity net joint moments during hopping. Journal of applied biomechanics, 26(3), 249-255.</li>
</ol>

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

Copyright

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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