Special Tests: Shoulder Instability and Labrum Pathology

Special Tests: Shoulder Instability (Apprehension) and Labrum Pathology

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>

Muscle Fiber Dysfunction - a general term used to encompass all commonly noted changes resulting from excessive stress to a muscle fiber, and the clinically observable phenomenon that result from those changes.
<ul>
 	<li>The term "muscle fiber dysfunction" has been chosen to describe this is a neuromyofascial phenomenon to separate the subject matter from information that may explain dysfunction originating from damage to a joint (e.g. arthritis), damage to a nerve (e.g. neuropraxia) or damage to fascia (e.g. fasciitis).</li>
</ul>
Observable Phenomena Associated with Muscle Fiber Dysfunction:
<ul>
 	<li>Increased tone (over-activity)
<ul>
 	<li>General increase in tissue density</li>
 	<li>Resistance to stretch</li>
 	<li>Changes in EMG activity</li>
 	<li>Changes in muscle spindle activity (H-reflex)</li>
 	<li>Twitch response</li>
</ul>
</li>
 	<li>Taut bands</li>
 	<li>Palpable nodules</li>
 	<li>Myalgia
<ul>
 	<li>Pain upon deep palpation</li>
 	<li>Latent trigger points (tender points)</li>
 	<li>Active trigger points</li>
 	<li>Referral pain</li>
 	<li>Diffuse myofascial pain and allodynia</li>
</ul>
</li>
 	<li>Centralization
<ul>
 	<li>Whiplash syndrome</li>
 	<li>Chronic low back pain</li>
 	<li>Fibromyalgia syndrome</li>
</ul>
</li>
</ul>
<h3>Pathobiology of Muscle Fiber Dysfunction:</h3>
<ol>
 	<li>Excessive Stress
<ul>
 	<li>Acute tissue trauma</li>
 	<li>Continuous low-load activity
<ul>
 	<li>Postural dysfunction</li>
</ul>
</li>
 	<li>Eccentric contractions</li>
</ul>
</li>
 	<li>Insufficient blood flow
<ul>
 	<li>Capillary restriction (especially during isometric contraction)</li>
 	<li>Insufficient recovery (cycling of motor units is insufficient)</li>
</ul>
</li>
 	<li>Metabolic crisis
<ul>
 	<li>Hypoxia</li>
 	<li>cytochrome c oxidase deficiency</li>
 	<li>Mitochondrial, sarcotubular system and cell membrane changes</li>
 	<li>Moth-eaten fibers and degeneration</li>
</ul>
</li>
 	<li>Muscle fiber changes
<ul>
 	<li>Taut bands and palpable nodules</li>
 	<li>Type I fiber hypertrophy</li>
 	<li>Increase in Type IIA fibers</li>
 	<li>Increase in transitional fibers</li>
 	<li>Preferential loss of Type I and/or Type II motor units</li>
 	<li>Infiltration of adipose and/or connective tissue</li>
</ul>
</li>
 	<li>Chemical change
<ul>
 	<li>Markers of inflammation and pain</li>
 	<li>Acidity (pH)</li>
 	<li>Excessive Ca2+</li>
 	<li>Excessive acetylcholine (ACh)</li>
</ul>
</li>
 	<li>Nervous system adaptation
<ul>
 	<li>Altered reflex sensitivity</li>
 	<li>Dorsal horn reorganization</li>
 	<li>Hippocampus inhibition</li>
 	<li>Autonomic system involvement</li>
</ul>
</li>
 	<li>Centralization</li>
</ol>
&nbsp;

Referred (Trigger Point) Pain - Pain that is generated by a trigger point, but is felt in a pattern that includes an area distal to that point. The pattern may be reproduced by stimulation of the original trigger point. Note, the distribution of referred trigger-point pain rarely completely congruent with the distribution of a peripheral nerve or dermatomal segment (1).
<ul>
 	<li>Example, many of the trigger points associated with muscles of the cervical spine may refer pain to the front, top or side of the head, and are thought to be one of the contributing factors to "tension type" and "cervicogenic" headaches.</li>
</ul>
<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>

Myalgia - muscle pain.

From the Greek prefix and suffix:
<ul>
 	<li>Myo - word-forming element meaning "muscle," from combining form of Greek mys for "muscle," literally translating to "mouse" (as in "little mouse under the skin") - <a href="https://www.etymonline.com/word/myo-#etymonline_v_45179" target="_blank" rel="noopener">etymology online</a></li>
 	<li>algia - word-forming element denoting "pain," from Greek algos "pain," . Related to alegein (of unknown origin) "to care about," originally "to feel pain." - <a href="https://www.etymonline.com/word/-algia#etymonline_v_8142" target="_blank" rel="noopener">etymology online</a></li>
</ul>

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>

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;

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>

Myofascial Pain Syndrome (MPS) - Diagnosed pain syndrome that generally includes (1-4):
<ol>
 	<li>Tenderness at points in firm bands of skeletal muscle</li>
 	<li>Specific patterns of pain referral associated with each point</li>
 	<li>Frequent emotional, postural, and behavioral contributing factors</li>
 	<li>Frequent associated symptoms and concomitant diagnoses</li>
 	<li>MPS is distinct diagnosis, separate from fibromyalgia</li>
</ol>
Alternatively, MPS has been defined as pain originating from trigger points (3).
<ul>
 	<li>Based on the Brookbush Institute's review of "Muscle Fiber Dysfunction and Trigger Points" it would seem that MPS encompasses all of the observable signs and symptoms associated with muscle fiber dysfunction, that are not fibromyalgia.</li>
</ul>
&nbsp;
<ol>
 	<li>Fricton, J. R., Kroening, R., Haley, D., &amp; Siegert, R. (1985). Myofascial pain syndrome of the head and neck: a review of clinical characteristics of 164 patients. Oral surgery, oral medicine, oral pathology, 60(6), 615-623.</li>
 	<li>Tough, E. A., White, A. R., Richards, S., &amp; Campbell, J. (2007). Variability of criteria used to diagnose myofascial trigger point pain syndrome—evidence from a review of the literature. The Clinical journal of pain, 23(3), 278-286.</li>
 	<li>Borg-Stein, J., &amp; Simons, D. G. (2002). Myofascial pain. Archives of physical medicine and rehabilitation, 83, S40-S47.</li>
 	<li>Harden, R. N., Bruehl, S. P., Gass, S., Niemiec, C., &amp; Barbick, B. (2000). Signs and symptoms of the myofascial pain syndrome: a national survey of pain management providers. The clinical journal of pain, 16(1), 64-72.</li>
</ol>

Twitch Response - A sudden contraction of fibers within a taut band when strummed (manually), needled, or compressed with a vibration massage device. The contractions may be observed visually, recorded electromyographically (EMG), or visualized with diagnostic ultrasound (1).
<ul>
 	<li>Sometimes referred to as a local twitch response and abbreviated "LTR".</li>
</ul>
<ol>
 	<li>Gerwin, R. D., &amp; Duranleau, D. (1997). Ultrasound identification of the myofacial trigger point. Muscle &amp; nerve, 20(6), 767-768.</li>
</ol>

Taut Band - an endogenous localized contracture within the muscle without activation of the motor endplate (1).
<ul>
 	<li>Palpation can be used to highlight the difference in tissue tension between a taut band and the surrounding fibers, by slowly "strumming" a muscle perpendicular to the fiber direction. Taut bands are often described as feeling like a "guitar string wound too tight".</li>
</ul>
<ol>
 	<li>Mense, S. (1997). Pathophysiologic basis of muscle pain syndromes: an update. Physical Medicine and Rehabilitation Clinics, 8(1), 23-53.</li>
</ol>

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>

Quasi-experimental Research - Studies in which the researchers introduce the independent variable with the intent of observing the outcome, but unlike true experimental research, group selection is not randomized.
<ul>
 	<li>In this study by Ghanbari et al., the independent variable was introduced by the the researchers to all individuals in the group, without randomization or a control group. Everyone was tested before treatment, received the same treatment, and was tested again after treatment.</li>
</ul>
<ol>
 	<li><a href="https://brentbrookbush.com/articles/research-corner/effect-knee-joint-mobilization-quadriceps-muscle-strength/" target="_blank" rel="noopener">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>
&nbsp;

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://brentbrookbush.com/private-yearly-plan/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;

Stability - the ability of a body to produce forces that will restore equilibrium when disturbed.
<ul>
 	<li>For example, when performing exercises on one leg (e.g. <a href="https://brentbrookbush.com/vimeo_videos/row-and-progressions/" target="_blank" rel="noopener">a single leg row</a>), stability would be the property of producing small forces that allow you to stay balanced on one leg while moving the load shifts your center of mass.</li>
</ul>

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>

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>

Retrospective study - a type of longitudinal study that looks backwards over a set of data to examine suspected factors in relation to an outcome that is established at the start of the study.
<ul>
 	<li>These studies are incredibly beneficial when large sets of high-quality data are available that can be analyzed for trends.</li>
 	<li>Unfortunately, these studies cannot be better than the data set that is being used (for example, incomplete or sloppy medical records would hinder analysis). Further, this type of research can be easily manipulated, either intentionally or unintentionally.</li>
</ul>
<ul>
 	<li>In this study by Chang et al., changes in muscle size were investigated and correlated with a history of chronic plantar fasciitis (1).</li>
</ul>
<ol>
 	<li><a href="https://brentbrookbush.com/articles/research-corner/ankle-and-foot/plantar-fasciitis-and-atrophy/" target="_blank" rel="noopener">Chang, R., Kent-Braun, JA., Hamill, J. Use of MRI for volume estimation of tibialis posterior and plantar intrinsic foot muscles in healthy and chronic plantar fasciitis limbs.  Clinical Biomechanics. 27 (2012) 500-505 </a></li>
</ol>

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>

Stability training  - An exercise or rehabilitation program designed to enhance the body's ability to stabilize; ability to maintain/restore balance.
<ul>
 	<li>Example, a program that prioritizes exercise progression over increases in repetitions, sets, load or speed.</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>

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>

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>

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>

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>

True Positive - the proportion of positives in a group that were assessed correctly
<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 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>

True Negative - the proportion of negatives in a group that were assessed correctly
<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>

Test-Item Cluster -  A specific group of special tests for a particular diagnosis that has greater accuracy than a single special test, as demonstrated by research.

For Example:
<ul>
 	<li><a href="https://brentbrookbush.com/vimeo_videos/park-et-al-subacromial-impingement-testing-cluster/" target="_blank" rel="noopener">Park et al. Shoulder Impingement Testing Cluster</a>
<ul>
 	<li><a href="https://brentbrookbush.com/vimeo_videos/hawkins-kennedy-and-yokum-tests/" target="_blank" rel="noopener">Hawkin's Kennedy</a></li>
 	<li><a href="https://brentbrookbush.com/vimeo_videos/infraspinatus-irrst-tests/" target="_blank" rel="noopener">Infraspinatus Strength Test</a></li>
 	<li><a href="https://brentbrookbush.com/vimeo_videos/painful-arc-test/" target="_blank" rel="noopener">Painful Arc Test</a></li>
</ul>
</li>
</ul>

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>

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>

Nutation - anterior rotation of sacrum relative to ilium, and/or relative posterior rotation of ilium relative to sacrum.
<ul>
 	<li>The <a href="https://brentbrookbush.com/articles/anatomy-articles/muscular-anatomy/erector-spinae/" target="_blank" rel="noopener">erector spinae</a> and <a href="https://brentbrookbush.com/articles/anatomy-articles/muscular-anatomy/psoas/" target="_blank" rel="noopener">psoas</a> are examples of muscle that may 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;

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>

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;

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>

Predictive values in diagnostic testing, are the proportion of true positives and true negatives. The positive predictive value (PPV) and negative predictive value (NPV) describe the accuracy of a diagnostic test; however, unlike sensitivity and specificity, predictive values are largely dependent on the dysfunctions prevalence in the examined population (1).

For example, imagine a patient who just tested positive on a special test. If the test was positive, what is the probability that they really have that dysfunction; how worried should they be? Now, imagine the same test performed on a very different individual in a different setting with very different subjective indicators. How do you think that would effect predictive value?
<ul>
 	<li>Positive predictive value (PPV) - describes the probability of having the dysfunction of interest in a subject with a positive result. Therefore PPV represents the proportion of patients with positive test result that are positive in a given population.</li>
 	<li>Negative predictive value (PPV) - describes the probability of not having the dysfunction of interest in a subject with a negative test result. Therefore NPV represents the proportion of patients without the disease that are negative in a given population.</li>
</ul>
<ol>
 	<li>Šimundić, A. M. (2009). Measures of diagnostic accuracy: basic definitions. Ejifcc, 19(4), 203</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>

Specificity: The probability of a negative test result in someone who does not have the pathology (the probability of a true negative). The ability to "specifically" identify only those individuals with the disease, by getting a negative result from everyone who does not.

Sensitivity: The probability of a positive test result in someone with the pathology (the probability of a true positive). This could also be viewed as the ability of a test to be "sensitive" enough to detect all of the positive individuals in a group of likely candidates.

Tension (physics) - may be described as a pulling force transmitted axially, or an action-reaction pair of forces acting at each end of a structure. Often this may be visualized as a "stretching" or "lengthening" force resulting in "tautness". The rope in a game of tug-of-war is a good example.
<ul>
 	<li>Example: Muscular tension is the result of contractile proteins attempting to pull a muscle to a shorter length while being resisted by joints, connective tissue and external loads.</li>
</ul>

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>

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>

Refractory period - cell membrane recovery time immediately following an action potential, during which another action potential is not possible.

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>

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>

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>

The term "release" in rehabilitation, performance, and manual therapy settings, generally refers to the feeling of a reduction in tissue tone, tension, density or activity in response to pressure, position, vibration, mobilization or manipulation of soft tissue. The mechanism that results in a feeling of "release" is likely a complex set of mechanical changes and neuromuscular reflexes (example, depicted below in the Schleip Model of Tissue Manipulation); however, it assumed that "autogenic inhibition" plays the largest role, as a result of stimulating golgi tendon organ, ruffini endings and/or pacinian corpuscles.

[caption id="attachment_115142" align="aligncenter" width="1288"]<a href="https://brentbrookbush.com/wp-content/uploads/2018/01/Schleip.png"><img class="size-full wp-image-115142" src="https://brentbrookbush.com/wp-content/uploads/2018/01/Schleip.png" alt="" width="1288" height="870" /></a> Tissue Manipulation Model - Schleip, R. (2003). Fascial plasticity–a new neurobiological explanation Part 2. Journal of Bodywork and movement therapies, 7(2), 104-116.[/caption]

Mitochondria: A double membrane organelle specialized for generating ATP via aerobic respiration (metabolism).
<ul>
 	<li>Mitochondrial density may imply a cell's activity level, and/or dependence on aerobic respiration for its primary function.</li>
</ul>
&nbsp;

Pigment - An organic compound that gives a characteristic color to plant or animal tissue.
<ul>
 	<li>Example: chlorophyll in plants, hemoglobin in blood, and myoglobin in muscle tissue</li>
</ul>

Myoglobin is a pigment found in muscle cells, that aids hemoglobin in providing oxygen  for aerobic metabolism.
<ul>
 	<li>Higher myoglobin concentrations within a muscle cell (e.g. as found in Type I fibers), allows for more oxygen to be carried, which enhances the cells ability to fuel aerobic metabolism.</li>
</ul>

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>

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;

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>

Viscera - The internal organs of the body within the chest (as the heart or lungs), and/or abdomen (as the liver, pancreas or intestines).
<ul>
 	<li>Example, the viscera of the upper thorax is protected by the rib cage.</li>
</ul>

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>

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>

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>".

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>

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>".

Rate Coding - It states that as intensity of a stimulus increases, the rate of action potentials increases - rate coding is sometimes called frequency coding. Rate coding is a model describing a type of neuronal communication which implies the amplitude and shape of an action potential may be relatively fixed (all-or-none principle) with additional information coded in the frequency of action potentials.
<ul>
 	<li>Rate coding was originally shown by <a title="Edgar Adrian" href="https://en.wikipedia.org/wiki/Edgar_Adrian">ED Adrian</a> and <a title="Yngve Zotterman" href="https://en.wikipedia.org/wiki/Yngve_Zotterman">Y Zotterman</a> in 1926 (1).</li>
</ul>
<ol>
 	<li>Adrian, E. D. (1926). The impulses produced by sensory nerve endings. The Journal of physiology, 61(1), 49-72.</li>
</ol>

Torque - Torque refers to a turning or twisting force.  Linear force results in torque when applied to a lever that moves in a circle around an axis.
<ul>
 	<li>In the human body, most muscles produce torque, because most bones move around the fixed axis of a joint.</li>
</ul>

Plyometric Exercise - Exercises done with the intent of increasing power that include a rapidly loaded eccentric, followed by a short "amortization phase" (isometric contraction) and rapid concentric contraction (1). Plyometric exercise is presumed to increase power by increasing or coordinating the contribution of myotatic reflex (stretch reflex), elastic recoil of eccentrically loaded connective tissues, and optimization of motor unit recruitment.
<ul>
 	<li>History: Verkhoshanski, a track and field coach in Russia developed a system of "shock training" or "jump training" (2,3). Fred Wilt, a former Purdue University women's track coach first coined the term plyometrics in 1975 to describe Verkhoshanki's training method, and aided in popularizing the term and training in the United States (4). The word plyometrics is derived from the Greek, plythein or plyo - to increase, and metric to measure.</li>
</ul>
<ol class="references">
 	<li id="cite_note-Wilt-6">Davies, G., Riemann, B. L., &amp; Manske, R. (2015). Current concepts of plyometric exercise. International journal of sports physical therapy, 10(6), 760.</li>
 	<li>Verkhoshanski Y. Perspectives in the improvement of speed‐strength preparation of jumpers. Yessis Rev of Soviet Phys Ed Sports. 1969;4:28‐34.</li>
 	<li>Verkhoshanski Y. Depth jumping in the training of jumpers. Track Tech. 1973;51:1618‐1619.</li>
 	<li>Wilt, F. (1984). Soviet theory, technique and training for running and hurdling (Vol. 1). Championship Books.</li>
</ol>

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;

Motor Unit: One nerve fiber (nerve cell axon) and all of the muscles cells (fibers) it innervates.
<ul>
 	<li>Example - Although a single muscle cell must fire completely or not at all, force output can be calibrated by the number and size of motor units recruited.</li>
</ul>
<ol>
 	<li>Saladin, K. (2012). Anatomy &amp; Physiology: The unity of form and function. (6th ed.). New York: McGraw-Hill.</li>
</ol>

Neuromuscular Junction: The functional connection between the synapse of a motor nerve and the motor end plate of a muscle cell.
<ul>
 	<li>Example - For an action potential to successfully initiate contraction, the action potential must result in the release of neurotransmitters across the neuromuscular junction.</li>
</ul>
<ol>
 	<li>Saladin, K. (2012). Anatomy &amp; Physiology: The unity of form and function. (6th ed.). New York: McGraw-Hill.</li>
</ol>

Action Potential: A rapid change in voltage of a cell membrane, briefly reversing the electrical polarity.
<ul>
 	<li>An action potential has a self-propagating effect, creating a wave depolarization along the entire length of the cell, in both muscle and nerve cells.</li>
</ul>
<ol>
 	<li>Saladin, K. (2012). Anatomy &amp; Physiology: The unity of form and function. (6th ed.). New York: McGraw-Hill.</li>
</ol>

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>

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>

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>

Responsiveness: The ability of a cell to respond or react to stimuli (1).

For example, a muscle cell may respond to chemicals/hormones in the bloodstream by increasing intra-cellular production of certain proteins.
<ol>
 	<li>Saladin, K. (2012). Anatomy &amp; Physiology: The unity of form and function. (6th ed.). New York: McGraw-Hill.</li>
</ol>

M-line - Refers to a dark line through the middle of a sacromere, bisecting the two halves between Z disks when viewed under a microscope.  The M-band is composed of proteins myomesin, C-protein, the M-line portion, as well as other cross-links between the thick filament system (myosin).

Example, Just as the Z disk anchors actin filaments, the M-line aids in anchoring myosin filaments.
<ol>
 	<li>Saladin, K. (2014). Anatomy &amp; physiology: The unity of form and function. McGraw-Hill Higher Education, New York. ISBN: 9780073403717</li>
</ol>

Sarcomere - A segment of a myofibril (muscle cell) from one Z disk to the next.  This is the smallest functional unit of a muscle cell. A muscle shortens because all of the individual sarcomeres shorten, pulling Z disks closer to one another.

Example: A sarcomere is the smallest functional unit of a muscle cell, discussed when teaching contractile proteins, the sliding filament theory and length/tension relationships.
<ol>
 	<li>Saladin, K. (2014). Anatomy &amp; physiology: The unity of form and function. McGraw-Hill Higher Education, New York. ISBN: 9780073403717</li>
</ol>
&nbsp;

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>

Z disk - Refers to a dark line between adjacent I-bands under a microscope.  This area is the border, or walls of the "sarcomere", and is comprised of connectin protein that acts as an anchor for the actin filaments.

Example, a sacromere (the smallest functional unit of a muscle cell) may be defined as a segment of a myofibrile between two Z disks.
<ol>
 	<li>Saladin, K. (2014). Anatomy &amp; physiology: The unity of form and function. McGraw-Hill Higher Education, New York. ISBN: 9780073403717</li>
</ol>
&nbsp;

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>

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>

Organelle - Any structure within a cell that carries out one of its metabolic roles.

Example: Mitochondria, nucleus, endoplasmic reticulum and the cell wall are all examples of organelles.
<ol>
 	<li>Saladin, K. (2014). Anatomy &amp; physiology: The unity of form and function. McGraw-Hill Higher Education, New York. ISBN: 9780073403717</li>
</ol>
&nbsp;

Nerve tissue consists of neurons and a much greater number of glial cells (supporting cells). One of the four basic types of animal tissue, these cells are specialized to detect stimuli, respond quickly and transmit coded information to other cells.
<ul>
 	<li>Example, the sciatic nerve is actually a bundle of axons from neurons (nerve cells) whose bodies are close to the spinal cord.</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>
&nbsp;

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>

Muscle Cells - These cells are specialized to respond to stimulation with contraction (movement) and are relatively elastic. There are 3 types of muscle cells/tissues; skeletal (striated), cardiac and smooth.

Of the 3 types of muscles cells, skeletal muscle is the only type that allows for voluntary control.
<ol>
 	<li>Saladin, K. (2014). Anatomy &amp; physiology: The unity of form and function. McGraw-Hill Higher Education, New York. ISBN: 9780073403717</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>

Post-activation potentiation (PAP) - A phenomenon in which a muscle’s force is acutely increased as a result of its contractile history (1).

Example, an individual may attempt to improve vertical jump height (<a href="https://brentbrookbush.com/vimeo_videos/box-jumps/" target="_blank" rel="noopener">box jumps</a>) by first performing a set of low volume, heavy <a href="https://brentbrookbush.com/vimeo_videos/back-squat/" target="_blank" rel="noopener">back squats</a>.  Further research is needed to optimize inter-set rest periods, total reps, load and volume.
<ol>
 	<li>Robbins, D. W. (2005). Postactivation potentiation and its practical applicability: a brief review. Journal of Strength and Conditioning Research, 19(2), 453.</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>

Power - the rate of force production. In health and human performance "power" is used most often to express speed and explosiveness, focusing on the rate or velocity component of the power equation depicted below.

Example, plyometric box jumps are done with the intent of increasing power and vertical jump height.
<ul>
 	<li>Physics: Power (measured in watts) is defined as the rate of work, where work is equal to force x displacement:</li>
</ul>
<a href="https://brentbrookbush.com/wp-content/uploads/2017/09/Power.gif"><img class="aligncenter size-full wp-image-111164" src="https://brentbrookbush.com/wp-content/uploads/2017/09/Power.gif" alt="" width="274" height="160" /></a>

Observational study - a study that draws inferences from a population or sample where the independent variable cannot be controlled due to ethical concerns or logistical constraints. For example, observational research may be done because participants and controls cannot be randomly assigned.

Example, the Souza et al. study (1) is observational because knee pain cannot be randomly assigned.  This study compared individuals with knee pain to "matched-controls" without knee pain.
<ol>
 	<li><a href="https://brentbrookbush.com/articles/research-corner/knee/predictors-excessive-hip-internal-rotation-during-running/" target="_blank" rel="noopener">Souza, R. B. &amp; Powers, C. M. (2009) An evaluation of hip strength and femoral structure in women with and without patellofemoral pain. The American Journal of Sports Medicine, 37(3), 579-587. doi: 10.1177/0363546508326711</a></li>
</ol>

Randomized Controlled Trial (RCT) - An RCT is an experimental study; that is the researchers introduce a variable with the intent of observing an outcome(s). However, in an RCT participants are randomly assigned to an experimental group (or multiple experimental groups), and compared to a randomly assigned control group (sham intervention or placebo). The control group gives baseline data to compare the experimental group against, reducing the likelihood that any trends noticed in the data were the result of confounding variables. More sophisticated research methods may include additional groups, for example experimental, experimental 2, control, placebo, nocebo, etc.

Example: In the study by Makofsky et al. (1) investigating the effect of joint mobilizations on hip abductor torque, participants were randomly assigned to either:
<ul>
 	<li>Control Group  - receiving sham therapy of grade I inferior mobilizations too gentle to have an effect on joint stiffness</li>
 	<li>Experimental Group - receiving the therapeutic intervention being tested of Grade IV inferior mobilizations</li>
</ul>
<ol>
 	<li><a href="https://brentbrookbush.com/articles/research-corner/hip/immediate-effect-grade-iv-inferior-hip-joint-mobilization-hip-abductor-torque-pilot-study-done/" target="_blank" rel="noopener">Makofsky, H, Panicker, S, Abbruzzese, J, Aridas, C, Camp, M, Drakes, J, Franco, C and Sileo R. (2007). Immediate effect of grade IV inferior hip mobilization on hip abductor torque: a pilot study. Journal of Manual and Manipulative Therapy, 15(2), 103-111</a></li>
</ol>

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.

Prospective study - a longitudinal study that follows a group of individuals over time (into the future) to determine how a set of predetermined factors effects, or is correlated with, certain outcome measures.
<ul>
 	<li>These studies are important for determining the cause of various orthopedic pathologies, because in most cases potentially harmful variables cannot be experimentally introduced to determine if they will result in injury.</li>
 	<li>Unfortunately, these studies are notoriously expensive, are vulnerable to participant attrition, and may not easily detect rare diseases or injuries.</li>
</ul>
Example, the study by Zazulak et al. (1) is a prospective study that demonstrated that slower reactivity of trunk muscles was correlated with an increased rate of knee injury over the course of a season.
<ol>
 	<li><a href="https://brentbrookbush.com/articles/research-corner/impaired-core-stability-predictor-knee-injury-risk/" target="_blank" rel="noopener">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></li>
</ol>

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>

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>

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>

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>

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>

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>

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

An anatomical direction; toward the top (above)

Example, the eyes are superior to the mouth

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.

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>

Special Tests: Shoulder Instability (Apprehension) and Labrum Pathology

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Anterior Instability and Labrum Pathology:

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