Introduction: Position Stand

Pre-manipulative Screening

Research Summary

Perception of Risk

Survey Data and Systematic Review

Published Case Series and Case Studies

Non-life-threatening Adverse Effects and Classification

Tissue Damage

Range of Motion and Cervical Vessel Insult

Correlation and Relative Risk

Joint Mobilizations and Manipulations: Risk of Adverse Events

REPSI

AOTA

NASM

ACSM

AFAA

CanFitPro

PTAGlobal

NCBTMB

TPTA

NYPT

WITS

ISSA

PACE

CIMSPA

Joint Mobilization and Manipulation: Risk of Adverse Events

Unscientific Thinking: The risks associated with manipulations and mobilizations, especially cervical manipulations, have been dramatically overstated in several publications. This has led to unsupportable and irrational recommendations including the elimination of manipulations from practice, mandating unreliable and insensitive special tests, and/or asserting that medical professionals should be held legally accountable for unforeseeable, exceedingly rare events. These assertions may be some of the most poignant examples of unscientific thinking in our field. This course reviews all of the available research, published survey data, and case reports that could be located at the time of publication. A thorough review highlights various aspects of analysis and treatment that have been &quot;conveniently forgotten&quot; in several previous publications (e.g. relative risk, rate of occurrence, correlation or <a id="etiology" data-tip="1490" target="_blank" href="/glossary-term/etiology" class="glossary">causation</a> etc.).
Example of Omitted Research: A review by Dabbs et al. demonstrated that current best evidence indicates that NSAIDs are likely several 100 times more dangerous than cervical manipulations (based on the rate of occurrence of adverse events). Further, several studies have demonstrated that cervical manipulations alone are more effective than physician care alone (including pharmacological intervention). This counter-intuitive finding suggests that receiving a cervical manipulation for neck pain is more likely to improve symptoms, and less likely to cause injury, than seeing a physician and taking an over-the-counter anti-inflammatory. Note, the Brookbush Institute recommends an <a id="integration" data-tip="1473" target="_blank" href="/glossary-term/integration" class="glossary">integrated</a> approach to treatment and is not recommending that NSAIDS, manipulations, or physician care should be reduced or omitted for the treatment of cervical pain.&#xA0;
<ul>
 <li>Dabbs, V., &amp;amp; Lauretti, W. J. (1995). A risk <a id="assessment" data-tip="1478" target="_blank" href="/glossary-term/assessment" class="glossary">assessment</a> of cervical manipulation vs. NSAIDs for the treatment of neck pain. Journal of Manipulative and Physiological Therapeutics, 18(8), 530-536.</li>
</ul>

<h3>Samples from this Course</h3>
Brookbush Institute&apos;s Position Stand&#xA0;
There is no evidence to suggest that manipulations/mobilizations are at higher risk than any other physical or pharmaceutical intervention commonly used to address orthopedic pain. In fact, there is evidence to suggest that manipulations and mobilizations are more effective, with less risk of adverse events than physician intervention for several orthopedic conditions. Serious adverse events do occur, but these exceedingly rare events are likely no more common than severe allergic reactions to aspirin or NSAIDs, the occurrence of cardiac episodes during vigorous exercise, and/or unforeseeable deaths during routine surgery. Last, there is currently no <a id="reliability" data-tip="1795" target="_blank" href="/glossary-term/reliability" class="glossary">reliable</a> and/or accurate method for identifying patients who may be at risk of a serious adverse event during manipulations/mobilizations.&#xA0;
<h4>Conservative Risk Estimations based on Current Research:</h4>
<ul>
 <li>Severe (risk of life or motor function loss) adverse events: 1/5,000,000+</li>
 <li>Non-life-threatening serious transient side-effects: 1/15,000+</li>
 <li>Radicular complaints and/or worsening symptoms: 1/1000+</li>
 <li>Post-treatment discomfort (lasting less than 24 hours): 1/10 - 1/100
 <ul>
 <li>Note, removing manipulations from treatment may not reduce the rate of post-treatment discomfort.</li>
 </ul>
 </li>
</ul>

<h3>Topics Covered in this Course</h3>
Survey Data, Reviews, and Case Studies
<ul>
 <li>Perception of risk:&#xA0;</li>
 <li>Survey Data and Systematic Review:
 <ul>
 <li>Cervical Spine Manipulation:&#xA0;</li>
 <li>Thoracic and Lumbar Manipulation:&#xA0;</li>
 </ul>
 </li>
 <li>Case Series and Case Studies:
 <ul>
 <li>Case Series</li>
 <li>Case studies</li>
 </ul>
 </li>
 <li>Non-life Threatening Adverse Effects</li>
</ul>
Proposed Mechanisms of Injury
<ul>
 <li>Force Necessary for Tissue Failure</li>
 <li>Structural Damage Pre and Post Manipulation</li>
 <li>Cervical Manipulations Use Less Than Available Active ROM</li>
 <li>Vessel Dissection and Occlusion</li>
</ul>
Correlation, Relative Risk, and Screening
<ul>
 <li>Correlation or Causation</li>
 <li>Relative Risk</li>
 <li>Pre-manipulative Screening</li>
</ul>

<h3>Related Courses</h3>
<ul>
 <li><a href="Joint%20Mobilization%20and%20Manipulation:%20Introduction" target="_blank" rel="noopener">Joint Mobilization and Manipulation: Introduction</a></li>
 <li><a href="https://brookbushinstitute.com/article/mobilization-and-manipulation-reliability-of-palpation-and-assessment" target="_blank" rel="noopener" style="letter-spacing: 0px;">Joint Stiffness </a><a id="assessment" data-tip="1478" target="_blank" href="/glossary-term/assessment" class="glossary">Assessment</a> by Palpation</li>
 <li><span style="background-color: transparent; font-family: inherit; font-size: inherit; font-style: inherit; font-variant-ligatures: inherit; font-variant-caps: inherit; font-weight: inherit; letter-spacing: 0px;"><a href="https://brookbushinstitute.com/course/effect-joint-mobilizations-manipulations" style="letter-spacing: 0px;"><span style="background-color: transparent; font-family: inherit; font-size: inherit; font-style: inherit; font-variant-ligatures: inherit; font-variant-caps: inherit; font-weight: inherit; letter-spacing: 0px;">Effects of Joint Mobilizations and Manipulations</a></li>
 <li><a href="https://brookbushinstitute.com/courses/joint-mobilizations-and-manipulations-evidence-based-teaching-and-learning" title="Joint Mobilization and Manipulation: Evidence-based Teaching and Learning" target="_blank" rel="noopener">Joint Mobilizations and Manipulations: Evidenced-based Teaching and Learning</a></li>
</ul>

Course Description: Risk of Adverse Events following Joint Mobilization and Joint Manipulation

Course Webinar: Are Manipulations Risky

<h3>Position Stand</h3>
There is no evidence to suggest that manipulations/mobilizations are at higher risk than any other physical or pharmaceutical intervention commonly used to address orthopedic pain. In fact, there is evidence to suggest that manipulations and mobilizations are more effective, with less risk of adverse events than physician intervention, for several orthopedic conditions. Serious adverse events do occur, but these exceedingly rare events are likely no more common than severe allergic reactions to aspirin or NSAIDs, the occurrence of cardiac episodes during vigorous exercise, and/or unforeseeable deaths during routine surgery. Last, there is currently no <a id="reliability" data-tip="1795" target="_blank" href="/glossary-term/reliability" class="glossary">reliable</a> and/or accurate method for identifying patients who may be at risk of a serious adverse event during manipulations/mobilizations.&#xA0;
<h3>Quick Summary:</h3>
<h4>Conservative Risk Estimations based on Current Research:</h4>
<ul>
 <li>Severe (risk of life or motor function loss) adverse events: 1/5,000,000+</li>
 <li>Non-life-threatening serious transient side-effects: 1/15,000+</li>
 <li>Radicular complaints and/or worsening symptoms: 1/1000+</li>
 <li>Post-treatment discomfort (lasting less than 24 hours): 1/10 - 1/100
 <ul>
 <li>Note, removing manipulations from treatment may not reduce the rate of post-treatment discomfort.</li>
 </ul>
 </li>
</ul>
<h4>Potential List of Adverse Events</h4>
<ul>
 <li>Cervical Spine: Stroke, vertebral artery dissection, brainstem or spinal cord injury, worsening neuropathy</li>
 <li>Thoracic Spine: Mechanical or vascular injuries to the spinal cord, pneumothorax and/or hemothorax, cerebrospinal fluid leak secondary to injury of the dural sleeve</li>
 <li>Lumbar Spine: Cauda equina syndrome, lumbar disk herniation/rupture, fracture, hematoma or hemorrhagic cyst, neurologic compromise, vascular compromise, <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> abscess formation</li>
</ul>
<h4>Pre-manipulative Screening:&#xA0;</h4>
<ul>
 <li>Subjective Assessment: There may be utility for a subjective questionnaire with the intent of identifying a serious adverse (Red Flag) event in progress.</li>
 <li>Vertebrobasilar Insufficiency (VBI) and Upper Cervical <a id="stability" data-tip="1193" target="_blank" href="/glossary-term/stability" class="glossary">Instability</a> Testing: The <a id="reliability" data-tip="1515" target="_blank" href="/glossary-term/reliability" class="glossary">reliability</a>, <a id="sensitivity" data-tip="1226" target="_blank" href="/glossary-term/sensitivity" class="glossary">sensitivity</a>, and positive <a id="predictive-values" data-tip="1219" target="_blank" href="/glossary-term/predictive-values" class="glossary">predictive values</a> of VBI and Cervical <a id="stability" data-tip="1193" target="_blank" href="/glossary-term/stability" class="glossary">Instability</a> Tests are far too low to be trusted to screen the general population for individuals at-risk of exceedingly rare events. It should also be noted that there is no evidence that serious adverse events are correlated with a positive result on VBI or upper cervical <a id="stability" data-tip="1193" target="_blank" href="/glossary-term/stability" class="glossary">Instability</a> testing, with or without the addition of manipulations.</li>
</ul>
<h3>Confounding Estimations of Risk (Author&apos;s Note)</h3>
The risks associated with manipulations and mobilizations have been dramatically overstated in various publications. These dramatized risks have resulted in unsupportable and irrational recommendations including the elimination of manipulations from practice, and/or mandating unreliable and insensitive special tests prior to manipulations, and/or asserting that medical professionals should be held legally accountable for unforeseeable, exceedingly rare events. These assertions may be some of the most poignant examples of unscientific thinking by licensed professionals in the allied health fields. The common fallacy that may be observed throughout these publications is a blatant disregard of probabilities including fallacious attempts to imply prevalence from case studies, failure to consider risk-to-benefit ratio, no consideration of the risk relative to other interventions, and a lack of consideration of confounding variables including rare anatomical abnormalities. To date, there is no evidence to suggest that manipulations are higher risk than any other physical or pharmaceutical intervention commonly used to address orthopedic pain, and the problems that arise in attempting to estimate the risks associated with manipulations and mobilizations are similar to the issues that arise when attempting to estimate risk for any medical intervention.&#xA0;
Based on the evidence currently available, there are several confounding factors that are likely to make estimating &quot;risk&quot; difficult.
<ul>
 <li>Under-reporting of Cases: There is a high likelihood of under-reporting of serious cases due to the potential risk of professional harm. A larger movement is needed to promote and praise no-fault retrospective analysis and the publication of case studies involving serious adverse events. This is not a recommendation for protection from negligence; however, it is important that organizations with the intent to represent a profession (e.g. American Physical Therapy Association, Federation of Chiropractic Licensing Boards, Etc.) aid in preventing legislation that may imply liability, and/or these organizations should aid in developing systems and legislation that promote blameless retrospective analysis.</li>
 <li>Undiagnosed and Rare Risk Factors: A review by Haneline et al. noted the almost all published case studies failed to rule out factors such as <a id="connective-tissue-cell" data-tip="1368" target="_blank" href="/glossary-term/connective-tissue-cell" class="glossary">connective tissue</a> aberrations, underlying arteriopathy, coexistent infection, etc., prior to labeling manipulation as the cause of the severe adverse event (51). In these cases, it may be hypothesized that the manipulation was the &quot;straw that broke the camel&apos;s back&quot;. That is, although the manipulation was the cause of the insult, the patient was uniquely susceptible and likely to have experienced a similar adverse event resulting from any vigorous force. A study discussed below by Triano et al. suggests that the forces imparted during the manipulation of the spine are similar to those experienced by airline baggage handlers (38). Could it be that a patient with a <a id="connective-tissue-cell" data-tip="1368" target="_blank" href="/glossary-term/connective-tissue-cell" class="glossary">connective tissue</a> aberration was highly likely to experience cervical vessel damage during a high-impact daily task (e.g. colliding with another pedestrian while quickly walking to work), but before that event could occur they received a cervical manipulation for neck pain?</li>
 <li>Serious Adverse Events in Progress: Several of the cases and reviews below suggest that the correlation between manipulation/mobilization and severe adverse events may be due to patients looking for care for a serious adverse event in progress. For example, a patient may visit a manual therapist first for a cervical artery dissection that results in neck pain and neurological signs consistent with cervical radiculopathy. This category of cases deserves further attention, as it may be possible to develop a <a id="reliability" data-tip="1795" target="_blank" href="/glossary-term/reliability" class="glossary">reliable</a> subjective questionnaire that aids in differentiating &quot;normal&quot; orthopedic symptoms from those symptoms that suggest a severe adverse event in progress, which could enhance expediency to emergency care.</li>
</ul>

Introduction: Position Stand and Summary

<h3>Survey Data, Reviews, and Case Studies</h3>
<ul>
 <li>Perception of risk: These studies suggest that despite a movement to pursue <a id="evidence-based-practice" data-tip="1532" target="_blank" href="/glossary-term/evidence-based-practice" class="glossary">evidence-based practice</a>, many clinicians (and some courts) have beliefs that do not accurately reflect the best evidence available regarding manipulations and the risk of adverse events.</li>
 <li>Survey Data and Systematic Review:
 <ul>
 <li>Cervical Spine Manipulation: Published studies and reviews imply that one in several million manipulations may be related to a vertebrobasilar accident or cerebrovascular accident (including cervical arterial dissection), suggesting these events should be considered exceedingly rare. Further, research has failed to correlate any <a id="specificity" data-tip="1224" target="_blank" href="/glossary-term/specificity" class="glossary">specific</a> risk factor that could be used to identify at-risk individuals prior to manipulation.</li>
 <li>Thoracic and Lumbar Manipulation: Studies demonstrate that serious adverse events from thoracic and lumbar manipulation are also exceedingly rare, thoracic manipulation likely results in the fewest adverse events and serious adverse events may be as strong, or more strongly correlated with physician visits.</li>
 </ul>
 </li>
 <li>Case Series and Case Studies:
 <ul>
 <li>Case Series: Published case series&#xA0;suggest that serious adverse events may occur following manipulation, they may require surgical intervention, they may progress quickly and require emergency care, and symptoms treated with manipulations may actually be the result of serious undiagnosed pathologies in progress.</li>
 <li>Case studies: Case studies may be important for identifying exceedingly rare events that may arise in the course of a manual therapist&apos;s career, including manipulation correlated with intradural hematoma, cauda equina ischemia, hemorrhage of a thoracic schwannoma, etc.</li>
 </ul>
 </li>
 <li>Non-life Threatening Adverse Effects:&#xA0;Less serious adverse events may occur with more frequency than serious adverse events following manipulation; however, they are likely still relatively rare. Additionally, minor side effects may occur following manipulation (e.g. headache, <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> soreness, fatigue, etc.); however, considering these events do not occur with less frequency when manipulation and stretching are removed from treatment, the frequency of these effects may represent the frequency of effects following any intervention plan.</li>
</ul>
<h3>Proposed Mechanisms of Injury</h3>
<ul>
 <li>Force Necessary for Tissue Failure:&#xA0;The mean force used during manipulation and mobilization techniques is well below the minimum threshold for increased risk of tissue injury, and may be comparable to the forces experienced during demanding manual labor. However, some care may be warranted for osteoporotic patients based on a presumed increase in the risk of laminar fracture and the potential for neurologic injury.</li>
 <li>Structural Damage Pre and Post Manipulation: Manipulations do not routinely result in tissue damage of facet joint capsules or disks, including damage to disks exhibiting signs of dysfunction prior to manipulation.</li>
 <li>Cervical Manipulations Use Less Than Available Active ROM:&#xA0;Pre-manipulative and thrust ROM during manipulation is less than the participant&apos;s active ROM, refuting claims that cervical manipulations are dangerous due to excessive lengthening of at-risk tissues.</li>
 <li>Vessel Dissection and Occlusion: Manipulation does not result in greater strain to cervical arteries than daily activity, does not result in changes in cervical blood flow in otherwise healthy adults, and only some evidence from animal studies suggests that significant atherosclerotic disease may be a contraindication.</li>
</ul>
<h3>Correlation, Relative Risk and Screening</h3>
<ul>
 <li>Correlation or Causation: Research suggests that the correlation between cervical artery dissection and manipulation/chiropractic care may be the result of patients seeking treatment for dissection in progress, and/or that manipulations/chiropractic care is no riskier than seeking care from a physician.</li>
 <li>Relative Risk: Manipulations are effective for improving both short-term and long-term outcomes, serious adverse effects are exceedingly rare, and current best evidence suggests chiropractic care and manipulations are likely safer than physician care or NSAIDs (for <a id="relevance" data-tip="1505" target="_blank" href="/glossary-term/relevance" class="glossary">relevant</a> orthopedic issues). Some evidence suggests that mobilizations result in slightly fewer adverse reactions than manipulations; therefore, mobilizations may be recommended for patients who exhibit signs that may increase their risk of adverse effects.</li>
 <li>Pre-manipulative Screening: The <a id="reliability" data-tip="1515" target="_blank" href="/glossary-term/reliability" class="glossary">reliability</a>, <a id="sensitivity" data-tip="1226" target="_blank" href="/glossary-term/sensitivity" class="glossary">sensitivity</a>, and positive <a id="predictive-values" data-tip="1738" target="_blank" href="/glossary-term/predictive-values" class="glossary">predictive value</a> of vertebrobasilar insufficiency (VBI) and upper cervical <a id="stability" data-tip="1193" target="_blank" href="/glossary-term/stability" class="glossary">instability</a> testing only reaches a level of &quot;fair&quot; when the criterion for a positive result is a relatively large change (4mm or combining multiple grades), and/or these tests are performed on a patient population with a much higher than normal prevalence of positive results. Many studies demonstrated zero or poor sensitivity/positive <a id="predictive-values" data-tip="1738" target="_blank" href="/glossary-term/predictive-values" class="glossary">predictive value</a>, even when used with high prevalence populations, suggesting that these tests cannot be trusted to screen the general population for individuals at-risk for exceedingly rare events. Last, it should also be noted that there is no evidence that serious adverse events are correlated with positive results on VBI or upper cervical <a id="stability" data-tip="1193" target="_blank" href="/glossary-term/stability" class="glossary">instability</a> testing, with or without the addition of manipulations.</li>
</ul>
<ul></ul>

Survey Data, Reviews and Cases

Various publications have exaggerated the risk of adverse events correlated with manipulations, and these exaggerations have likely resulted in the inaccurate beliefs held by many clinicians. A study by Puentedura et al. collected surveys from 1000 physical therapists, demonstrating that the gross majority (90%+) believed that <a href="https://brentbrookbush.com/articles/manual-therapy/joint-manipulation-thoracic-spine/" target="_blank" rel="noopener">thoracic</a> and <a href="https://brentbrookbush.com/articles/manual-therapy/joint-manipulation-lumbar-spine-sacroiliac-joint-pubic-symphysis/" target="_blank" rel="noopener">lumbar manipulations</a>&#xA0;were safe and effective; however, a smaller percentage&#xA0;(68.9%) believed&#xA0;<a href="https://brookbushinstitute.com/article/manipulations-cervical-spine/">cervical spine manipulations</a> were safe and effective (1). A belief elicitation study by Hincapi&#xE9; et al. surveyed 47 clinicians demonstrating that chiropractors expressed the most optimistic beliefs, physicians expressed neutral beliefs; and spine surgeons expressed slightly more pessimistic beliefs. A general synopsis of findings suggests clinicians with the most optimistic views believed that manipulations reduced the incidence of acute herniation by about 60%, while the most pessimistic clinicians believed manipulations increased the incidence of herniations by about 30% (2). Note, neither of these estimations is close to the actual probability of risk or probable effect on outcomes resulting from the addition of manipulations to practice. Boucher et al. reviewed 6 court cases of aggravated lumbar herniation symptoms following chiropractic care, and it appears these fallacious perceptions have also influenced legislation and/or legal precedent in some courts:
<ul>
 <li>&quot;1) informed consent is an ongoing process that cannot be entirely delegated to office personnel; 2) when the patient&apos;s history reveals risk factors for lumbar disc herniation the chiropractor has the duty to rule out disc pathology as an <a id="etiology" data-tip="1489" target="_blank" href="/glossary-term/etiology" class="glossary">etiology</a> for the symptoms presented by the patients before beginning anything but conservative palliative treatment; 3) lumbar disc herniation may be triggered by spinal manipulative therapy on vertebral segments distant from the involved herniated disc&#xA0;such as the thoracic spine&quot;.</li>
</ul>
If the court had acted in good faith, they may have referred to a comprehensive literature/systematic review, interpreted by an experienced practitioner/expert, and compared the assessed risk of manipulations to the risk inherent in other commonly used interventions for the treatment of similar orthopedic conditions (3). These studies suggest that despite a movement to pursue <a id="evidence-based-practice" data-tip="1532" target="_blank" href="/glossary-term/evidence-based-practice" class="glossary">evidence-based practice</a>, many clinicians (and some courts) have beliefs that do not accurately reflect the best evidence available regarding manipulations and the risk of adverse events.&#xA0;

<h4>Cervical Spine</h4>
Research suggests that the occurrence of serious adverse effects is extremely rare. Margarey et al. conducted a survey study with members of the Manipulative Physiotherapists Association of Australia (740 mailed/480 returned surveys), which included reporting of any adverse events. The finding suggests that serious complications occur at a rate of approximately 1/1000 years of practice (4). This rate implies that 1 incident would occur for about 3% of all manual therapists who practiced for at least 30 years. Stevinson et al. asked the Association of British Neurologists to return surveys reporting cases of complications occurring within 24 hours of manipulation in the previous 12 month period. Of 323 members, 239 responded, 24 reported at least one case within the last 12 months, 35 adverse events were reported in total, only 10 adverse events involved stroke or vessel dissection, and only 6 involved worsening neuropathy (5). To add perspective to the study findings, this survey recruited British Neurologists and not manual therapy practitioners, implying that of all the emergent cases referred to 240 neurologists over 12 months in an area including 1000s of manual therapists, only 10 life-threatening incidents were reported, and no attempt was made to determine whether these issues were in process prior to manipulation. Haldeman et al. published a study that included all reported cases of vertebral artery dissection (VAD) following cervical manipulation between 1988-1997 from the Canadian Chiropractic Protective Association, which represents 85% of practicing chiropractors in Canada. Based on the survey data, it was estimated that 134,466,765 cervical manipulations were performed during this 10-year period, resulting in a calculated rate of VAD following cervical manipulations of 1/5,846,381 (6). In a comprehensive systematic review of published cases reporting adverse events following manipulation up to the year 2014, Kranenburg et al. again found relatively few published cases (144 published cases), and the only correlation between cerebrovascular accident (CVA) and manipulations was most patients being younger than 45 years of age. Further, there were no correlations made that would aid in identifying at-risk individuals prior to manipulation or refine manipulation techniques to reduce the occurrence of CVA (7). Rothwell et al. used hospital records in Ontario, Canada from 1993 - 1998 to identify vertebrobasilar accidents (VBA) without a previous history of stroke. Of the 582 VBA cases identified, individuals who were younger than 45 years old were 5 times more likely to have seen a chiropractor in the previous week; however, they were also 5 times more likely to have visited a physician 3 or more times in the previous month for a cervical diagnosis. No correlations could be identified between the investigated factors and VBA for individuals older than 45 years of age, and the researchers stated that any significant associations were difficult to identify due to the rarity of VBAs and the high volume of chiropractic treatments (8). Smith et al. asserted that manipulative therapy was an independent risk factor for vertebral artery dissection; however, the conclusion is questionable. The researchers searched 5 years of hospital records to identify patients less than 60 years of age with evidence of cervical arterial dissection (CAD), demonstrating that individuals in the CAD group were 11% more likely to have had cervical manipulation, but also 36% more likely to have had neck pain when compared to controls (9). This study implies that neck pain is more strongly correlated with CAD, and without comparing the risk of manipulation to other interventions for neck pain, the data on manipulations are cherry-picked, and/or the researchers failed to develop a useful matched control (i.e. participants with neck pain who did not receive manipulations). Haldeman et al. performed a retrospective review of 64 previously unpublished medicolegal records describing cerebrovascular ischemia after cervical spine manipulation spanning 16 years, from both the US and Canada. A consistent <a id="assessment" data-tip="1481" target="_blank" href="/glossary-term/assessment" class="glossary">evaluation</a> tool was developed and used to evaluate all records, and statistical analysis was used to identify means, frequency, prevalence, correlation, etc. Not a single factor could be identified as a significant prognostic indicator of CVA, resulting in the author&apos;s conclusion that &quot;cerebrovascular accidents after manipulation appear to be unpredictable and should be considered an inherent, idiosyncratic, and rare complication of this treatment approach&quot; (10). These published studies and reviews imply that one in several million manipulations may be related to a VBA or CVA (including CAD), suggesting these events should be considered exceedingly rare. Further, research has failed to correlate any <a id="specificity" data-tip="1224" target="_blank" href="/glossary-term/specificity" class="glossary">specific</a> risk factor that could be used to identify at-risk individuals prior to manipulation.
<h4>Thoracic Spine and Lumbar Spine</h4>
Severe adverse reactions correlated with thoracic and lumbar manipulation may be rarer than adverse events associated with cervical manipulations. Rydell et al. searched claims from three separate insurance companies to assemble 54 cases of injury following manipulation over a two-year period. Of the 54 cases, only 6 cases involved the thoracic spine suggesting the thoracic spine may be the least vulnerable segment, 24 cases involved the lumbar spine and sacroiliac joint resulting in mostly worsening herniation symptoms, and only one case of paraparesis (in conjunction with osteoporosis and an L3 <a id="compression" data-tip="1595" target="_blank" href="/glossary-term/compression" class="glossary">compression</a> fracture), and 21 cases involved the cervical spine with only 3 of those cases including CVA (11). A systematic review by Puentedura et al. investigated the available peer-reviewed, published literature for severe adverse reactions following thoracic spine manipulation between 1950-2015, and only 7 cases were found. Reported injuries included mechanical or vascular injuries to the spinal cord, with 2 cases including pneumothorax and/or hemothorax, and one case including cerebrospinal fluid leak secondary to injury of the dural sleeve (12). Senstad et al. performed a prospective clinic-based survey including 4712 treatments performed by 102 chiropractors in Norway. The finding suggested that following thoracic manipulation relatively minor adverse reactions were more likely to occur during the first treatment session, and appeared to occur more often when more than one spinal region was treated in a single session, or when the thoracic spine was treated alone. Additionally, the study demonstrated that adverse reactions were &quot;uncommon&quot;, and no correlations could be determined between adverse reactions and prognostic indicators (13). Herbert et al. performed a systematic review of published, peer-reviewed cases of adverse events following manipulation of the low back region up to the year 2012, resulting in 2046 studies screened, and the inclusion of 41 publications reporting on 77 cases. The reported adverse events included cauda equina syndrome (29 cases), lumbar disk herniation (23 cases), fracture (7 cases), hematoma or hemorrhagic cyst (6 cases), and additional less common events (12 cases, 16%) including neurologic compromise, vascular compromise, soft tissue trauma, <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> abscess formation, disrupted fracture healing, and esophageal rupture (14). Kim et al. performed a systematic review of peer-reviewed published literature from 1911-1996, including 61 reported cases of cauda equina syndrome or disc rupture following lumbar manipulation. This group generally publishes well-supported conclusions reflecting findings; however, in this review, they made the statement, &quot;...we assumed that cauda equina syndrome and/or disc rupture is far more common than the literature would reflect&quot;, despite only identifying 61 credible case studies in multiple databases with an 85-year reference range (15). Oliphant et al. performed a systematic review and risk <a id="assessment" data-tip="1478" target="_blank" href="/glossary-term/assessment" class="glossary">assessment</a> based on current data, and their conclusion was that the risk of manipulation causing a clinically worsened lumbar disk herniation or cauda equina syndrome was less than 1 in 3.7 million (16). Hincapie et al. used a self-controlled case series design, and population-based healthcare databases in Ontario, Canada, to investigate all adults with acute lumbar disc herniation (LDH) requiring emergency department (ED) visit and early surgical intervention between April 1994 and December 2004, and determined that the events were as strongly correlated with physician visits as with chiropractor visits (17). These studies demonstrate that serious adverse events from thoracic and lumbar manipulation are also exceedingly rare, thoracic manipulation likely results in the fewest adverse events, and serious adverse events may be as strong, or more strongly correlated with physician visits. However, these reviews may aid in developing a list of &quot;red flag&quot; events that could result in better screening for pathology in progress, and/or a quicker/better response to serious adverse events post manipulation. A summary of &quot;red flag&quot; events is discussed below.

<h4>Published Case Series</h4>
Due to the relative scarcity of systematic reviews and survey studies, several case series and case studies have been included in this review to aid in refining recommendations. Note, case studies/series should aid in identifying potential issues, and by definition cannot use statistical methods to imply prevalence or imply a probability of risk. Di Fabio et al. reviewed several databases using a date range from 1925-1997 and found evidence of 32 deaths from arterial dissection or brain stem lesion following cervical manipulations (18). Oppenheim et al. reviewed 6 years of patient records and identified 18 cases indicating complications from cervical, thoracic or lumbar spine manipulation. Of the 18 cases, 16 required surgical intervention, 9 had excellent outcomes, 7 had good outcomes, and 3 patients died from unrecognized malignancies (19). The 3 deaths from unrecognized malignancies are a curious finding, and maybe evidence that some cases of injury following manipulation are actually examples of manipulations performed on patients with serious pathology in progress. Hufungel et al. investigated 10 cases of vertebral artery dissection following cervical manipulations, 5 acute cases were referred to the clinic during a 14 month period, and 5 cases with a history of related symptoms responded to a TV broadcast reaching approximately 1.5 million people. Unfortunately, these cases did not reveal any commonalities that may indicate a means of screening patients or reducing risk (20). Haldeman et al. reviewed several databases with a date range between 1911-1989 and found ten reported cases of cauda equina syndrome following lumbar manipulation that resulted in poor outcomes because the chiropractor or physician failed to recognize the severity of the issues resulting in delayed treatment (21). Although the implication of these cases studies is serious and implies that more time may need to be spent during practitioner education to identify serious adverse reactions, some consideration should be given to the challenge of identifying an issue that is likely to occur 1 time in several million manipulations. In summary, published case series suggest that serious adverse events may occur following manipulation, they may require surgical intervention, they may progress quickly and require emergency care, and symptoms treated with manipulations may actually be the result of serious undiagnosed pathologies in progress.
<h4>Published Case Studies</h4>
Case studies may highlight additional concerns and potential risks. Ruelle et al. reported a case of thoracic epidural hematoma following manipulation, noting it was only the 3rd reported case, and further that surgical evacuation resulted in a complete recovery (22). In 2016, Hdeib et al. documented the hemorrhage of a thoracic schwannoma (<a id="nerve-cell" data-tip="1361" target="_blank" href="/glossary-term/nerve-cell" class="glossary">nerve</a> sheath tumor) following thoracic manipulation, resulting in intradural hematoma and paraplegia. Obviously, the outcome of this case was the unfortunate congruence of several exceedingly rare events (23). Yang et al. published a case of cauda equina syndrome immediately following vigorous low back massage and spinal manipulation, resulting in a need for emergency surgical intervention. Note, the patient fully recovered (24). In separate publications by Solheim et al. and Cheng et al., a case was described of lumbar epidural hematoma following spinal manipulation. The symptoms were similar to cauda equina syndrome, requiring emergency surgical evacuation, which resolved symptoms (25, 26). Morandi et al. reported a case of cauda equina ischemia following lumbar manipulation that was not the result of herniation or bony fragment, which may imply that manipulation resulted in micro-vascular trauma (27). Kornberg, E. published a case of a 44-year old man, whose sequence of pathology appears to be acute aortic occlusion resulting from lumbar artery aneurysm, following a chiropractic manipulation (28). Case studies may be important for identifying exceedingly rare events that may arise in the course of a manual therapist&apos;s career, including manipulation correlated with intradural hematoma, cauda equina ischemia, hemorrhage of a thoracic schwannoma, etc.&#xA0; Again, these case studies cannot be used to imply prevalence or the probability of risk.
<table style="border-collapse: collapse;" border="1">
 <tbody>
 <tr>
 <td>
 <h4>Potential List of Adverse Events</h4>
 <ul>
 <li>Cervical Spine: Stroke, vertebral artery dissection, brainstem or spinal cord injury, worsening neuropathy</li>
 <li>Thoracic Spine: Mechanical or vascular injuries to the spinal cord, pneumothorax and/or hemothorax, cerebrospinal fluid leak secondary to injury of the dural sleeve.</li>
 <li>Lumbar Spine: Cauda equina syndrome, lumbar disk herniation/rupture, fracture, hematoma&#xA0;or hemorrhagic cyst, neurologic compromise, vascular compromise, <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> abscess formation</li>
 </ul>
 </td>
 </tr>
 </tbody>
</table>

<h4>Non-life-threatening Adverse Effects:&#xA0;</h4>
Non-life threatening, transient, and/or minor side-effects following manipulation likely occur at a higher rate, but studies suggest these incidents are also rare. A survey study by Dvo&#x159;&#xE1;k et al. demonstrated that non-life-threatening transient side-effects such as disturbances of consciousness or radicular signs following cervical manipulations occurred at a rate of 1/16,716, and increased pain and transient sensorimotor deficits with precise radicular distribution following lumbar manipulation occurred at a rate of 1/20,125 (29). Theil et al. performed a prospective national survey, demonstrating that of 50,000 cervical manipulations performed, no serious adverse events were recorded, minor adverse events occurred less than 5% of the time, and many of the relatively minor complaints (e.g. radicular pain) occurred less than 0.1% of the time (30). A study of 283 patients by Cagnie et al. indicates that reactions to spinal manipulation (headache, soreness, fatigue) may be more common, but are almost always benign and short duration (less than 24 hours) (32). Last, Paanalahti et al. demonstrated that less serious, transient side-effects following manual therapy were fairly common (1 - 10%), with the most common being <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> soreness. Interestingly, eliminating cervical manipulation and stretching from intervention plans did not change this rate of occurrence (33). These studies suggest that less serious adverse events may occur with more frequency than serious adverse events following manipulation; however, they are likely still relatively rare. Additionally, minor side effects may occur following manipulation (e.g. headache, <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> soreness, fatigue, etc.); however, considering these events do not occur with less frequency when manipulation and stretching are removed from treatment, the frequency of these effects may represent the frequency of effects following any intervention plan.
<table style="border-collapse: collapse;" border="1">
 <tbody>
 <tr>
 <td>
 <h4>Conservative Risk Estimations Based on Current Research:</h4>
 <ul>
 <li>Severe (risk of life or motor function loss) adverse events: 1/5,000,000+</li>
 <li>Non-life threatening transient side-effects: 1/15,000+</li>
 <li>Radicular complaints and/or worsening symptoms: 1/1000+</li>
 <li>Post-treatment discomfort (lasting less than 24 hours): 1/10 - 100
 <ul>
 <li>Interestingly, Paanalahti et al. demonstrated that removing manipulations from treatment did not reduce the rate of post-treatment discomfort symptoms, suggesting this rate may be the rate associated with interventions in general, and not <a id="specificity" data-tip="1224" target="_blank" href="/glossary-term/specificity" class="glossary">specific</a> to manipulations (33).</li>
 </ul>
 </li>
 </ul>
 </td>
 </tr>
 </tbody>
</table>
<h4>Professional Consensus to Classify Adverse Events:</h4>
Attempts have been made to classify adverse events following manipulation by professional consensus. Kranenburg et al. sent multiple surveys regarding classification criteria to Dutch medical specialists, manual therapists, and patients. At least 75% consensus was achieved for 13 reactions that should be classified as adverse events within a given duration, including anxiety, altered sensation, coma, death, dislocation, dizziness, fainting, flushing, fracture, increased pain during movement, <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> tenderness, pain, radiating pain, skin rash, stroke, and transient ischemic attack. Consensus/agreement was weaker for relatively minor adverse reactions (). In another consensus study published by Carnes et al., an expert panel of 50 individuals from various medical professions were recruited into 1, 2, or 3 rounds of panel discussions to aid in defining adverse events. The following definitions resulted from at least 74% consensus from the panel:
<ul>
 <li>Major adverse events are medium to long term, moderate to severe, and are unacceptable. They normally require further treatment and are serious and distressing.</li>
 <li>Moderate adverse events are as major adverse events but only moderate in severity.</li>
 <li>Mild and not adverse events are short-term and mild, non-serious, the patient&apos;s function remains intact, and they are transient/reversible. No treatment alterations are required because the consequences are short-term and contained.</li>
</ul>
Although these studies are a significant first step toward the development of criteria that may be useful beneficial for screening and reporting adverse events, more research is needed to match reported cases, symptomatology, and best-practice recommendations.
Non-life threatening, transient, and/or minor side-effects following manipulation likely occur at a higher rate, but studies suggest these incidents are also rare. A survey study by Dvo&#x159;&#xE1;k et al. demonstrated that non-life-threatening transient side-effects such as disturbances of consciousness or radicular signs following cervical manipulations occurred at a rate of 1/16,716, and increased pain and transient sensorimotor deficits with precise radicular distribution following lumbar manipulation occurred at a rate of 1/20,125 (29). Theil et al. performed a prospective national survey, demonstrating that of 50,000 cervical manipulations performed, no serious adverse events were recorded, minor adverse events occurred less than 5% of the time, and many of the relatively minor complaints (e.g. radicular pain) occurred less than 0.1% of the time (30). A study of 283 patients by Cagnie et al. indicates that reactions to spinal manipulation (headache, soreness, fatigue) may be more common, but are almost always benign and short duration (less than 24 hours) (32). Last, Paanalahti et al. demonstrated that less serious, transient side-effects following manual therapy were fairly common (1 - 10%), with the most common being <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> soreness. Interestingly, eliminating cervical manipulation and stretching from intervention plans did not change this rate of occurrence (33). These studies suggest that less serious adverse events may occur with more frequency than serious adverse events following manipulation; however, they are likely still relatively rare. Additionally, minor side effects may occur following manipulation (e.g. headache, <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> soreness, fatigue, etc.); however, considering these events do not occur with less frequency when manipulation and stretching are removed from treatment, the frequency of these effects may represent the frequency of effects following any intervention plan.
<table style="border-collapse: collapse;" border="1">
 <tbody>
 <tr>
 <td>
 <h4>Conservative Risk Estimations Based on Current Research:</h4>
 <ul>
 <li>Severe (risk of life or motor function loss) adverse events: 1/5,000,000+</li>
 <li>Non-life threatening transient side-effects: 1/15,000+</li>
 <li>Radicular complaints and/or worsening symptoms: 1/1000+</li>
 <li>Post-treatment discomfort (lasting less than 24 hours): 1/10 - 100
 <ul>
 <li>Interestingly, Paanalahti et al. demonstrated that removing manipulations from treatment did not reduce the rate of post-treatment discomfort symptoms, suggesting this rate may be the rate associated with interventions in general, and not <a id="specificity" data-tip="1224" target="_blank" href="/glossary-term/specificity" class="glossary">specific</a> to manipulations (33).</li>
 </ul>
 </li>
 </ul>
 </td>
 </tr>
 </tbody>
</table>
<h4>Professional Consensus to Classify Adverse Events:</h4>
Attempts have been made to classify adverse events following manipulation by professional consensus. Kranenburg et al. sent multiple surveys regarding classification criteria to Dutch medical specialists, manual therapists, and patients. At least 75% consensus was achieved for 13 reactions that should be classified as adverse events within a given duration, including anxiety, altered sensation, coma, death, dislocation, dizziness, fainting, flushing, fracture, increased pain during movement, <a id="muscle-cell" data-tip="1781" target="_blank" href="/glossary-term/muscle-cell" class="glossary">muscle</a> tenderness, pain, radiating pain, skin rash, stroke, and transient ischemic attack. Consensus/agreement was weaker for relatively minor adverse reactions (). In another consensus study published by Carnes et al., an expert panel of 50 individuals from various medical professions were recruited into 1, 2, or 3 rounds of panel discussions to aid in defining adverse events. The following definitions resulted from at least 74% consensus from the panel:
<ul>
 <li>Major adverse events are medium to long term, moderate to severe, and are unacceptable. They normally require further treatment and are serious and distressing.</li>
 <li>Moderate adverse events are as major adverse events but only moderate in severity.</li>
 <li>Mild and not adverse events are short-term and mild, non-serious, the patient&apos;s function remains intact, and they are transient/reversible. No treatment alterations are required because the consequences are short-term and contained.</li>
</ul>
Although these studies are a significant first step toward the development of criteria that may be beneficial for screening and reporting adverse events, more research is needed to match reported cases, symptomatology, and best-practice recommendations.

Proposed Mechanisms of Injury

<h4>Force Necessary for Tissue Failure</h4>
Unfortunately, relatively few comparative studies have been published that may aid in determining recommended upper limits of force during mobilization and manipulation techniques. A study by Sran et al. demonstrated that the mean load resulting in micro-fracture&#xA0;of the thoracic spine was&#xA0;479 N (SD 162 N), and the mean PA force imparted by a clinician was 145 N (SD 38 N); suggesting there is a considerable buffer between manipulation force and the force necessary to result in micro-fracture (36). Stemper et al. demonstrated that chest compression&#xA0;was&#xA0;1.8% - 4.5% of total chest depth during a typical maximum effort thoracic manipulation performed by an experienced chiropractor. Based on prior research and data using the&#xA0;<a title="Learn more about Abbreviated Injury Scale from ScienceDirect&apos;s AI-generated Topic Pages" href="https://www.sciencedirect.com/topics/medicine-and-dentistry/abbreviated-injury-scale">Abbreviated Injury Scale</a> (AIS), this study suggests chiropractors use 20% of the force necessary to achieve a 10% increase in the risk of the lowest-rated <a id="compression" data-tip="1595" target="_blank" href="/glossary-term/compression" class="glossary">compression</a> injury (37). Triano et al. investigated forces from 3 lumbar manipulation techniques on 11 healthy volunteers, using computer modeling to estimate the amount of force through vertebral structures. Findings suggest that practitioners may alter force with changes in technique, intent, <a id="posture" data-tip="1658" target="_blank" href="/glossary-term/posture" class="glossary">posture</a> or speed, and that forces imparted on the spine are likely similar to those experienced by airline baggage handlers (38). Boonyoung et al. used modeling to approximate the effect of a simulated 100 N central PA lumbar mobilization on healthy and osteoporotic L1 vertebrae. The findings suggest that a fracture is most likely to occur at the spinous process of a healthy vertebra; however, osteoporosis may alter force absorption in a way that increases the risk of fracture at the pedicles and/or laminae (which may increase the risk of neurologic injury). Note, this study did not suggest that 100N of force was sufficient to result in a fracture (39). Based on the few studies currently available, it may be reasonable to suggest that the mean force used during manipulation and mobilization techniques is well below the minimum threshold for increased risk of tissue injury, and may be comparable to the forces experienced during demanding manual labor. However, some care may be warranted for osteoporotic patients based on a presumed increase in the risk of laminar fracture and the potential for neurologic injury.
<h4>Structural Damage Before and After Manipulation</h4>
Two studies were located that specifically compared tissue integrity before and after manipulation. Ianuzzi et al. used cadaver specimens to demonstrate that simulated high-velocity lumbar manipulation forces were far less than the amount of force necessary to result in damage to facet joint capsules (40). And, Chrisman et al. performed a myelogram before and after manipulation in individuals with lumbar intervertebral disc syndrome, demonstrating no change in myelogram findings for any participant (41). These studies are direct evidence that manipulations do not routinely result in tissue damage of facet joint capsules or disks, including damage to disks exhibiting signs of dysfunction prior to manipulation.

Cervical Manipulations Use Less Than Available Active ROM
Several studies have demonstrated that the ROM used during cervical manipulations is less than the participant&apos;s active ROM. Van Geyt et al. demonstrated that cervical manipulation magnitude did not exceed active ROM; further, cavitation occurrence was correlated with frontal plane ROM, sagittal acceleration, total velocity, and practitioner experience (42). Liguo et al. used motion capture technology to demonstrate that cervical ROM during cervical rotation-traction manipulation was less than the patient&apos;s active ROM, the head rotation angle was similar during pre-manipulation and thrust positions, and thrust direction was primarily vertical (43). Klein et al. used 3D electrogoniometry to demonstrate that the ROM used during cervical manipulation by an experienced practitioner was significantly less than active ROM for 14 asymptomatic subjects, and total ROM used was significantly altered by which side or segment was manipulated. Mean ROM for manipulations was 30&#xB0; <a id="axial-skeleton" data-tip="1292" target="_blank" href="/glossary-term/axial-skeleton" class="glossary">axial</a> rotation, 46&#xB0; <a id="lateral" data-tip="1567" target="_blank" href="/glossary-term/lateral" class="glossary">lateral</a> bending, and 2&#xB0; flexion (44). Salem et al. used a CT scan to investigate the cervical pre-manipulative position, demonstrating that the head and neck were rotated to the left and laterally flexed to the right, while the lower cervical spine exhibited rotation to the right. Again, segmental rotation ROM in the pre-manipulative position was less than the participant&apos;s active ROM (45). In summary, these studies demonstrate that pre-manipulative and thrust ROM is less than the participant&apos;s active ROM, refuting claims that cervical manipulations are dangerous due to excessive lengthening of at-risk tissues.
Vessel Dissection and Occlusion
A proposed mechanism for serious adverse events following cervical manipulations is injury or occlusion of cervical arteries; however, the research does not <a id="base-of-support" data-tip="1197" target="_blank" href="/glossary-term/base-of-support" class="glossary">support</a> this assertion. Herzog et al. demonstrated that cervical manipulations did not result in greater strain on the carotid arteries than normal daily activity (46). Quesnele et al. demonstrated that neither the head position nor thrust used during manipulation had any significant effect on blood flow in the vertebral arteries in healthy young men (47). And, an RCT by Licht et al. demonstrated that cervical manipulation did not result in any significant change in vertebral artery flow or velocity in individuals with biomechanical dysfunction (48). Two additional animal studies suggest that advanced atherosclerotic disease may be a confounding variable. A study using rabbits by Qi et al. suggested that there was some evidence that severe atherosclerosis plaques may be vulnerable during cervical manipulation, based on post-manipulation blood profiles (49). In another animal study&#xA0; (monkeys) by Guan et al., the combination of extreme rotation angle and significant atherosclerotic disease had an effect on blood flow of the internal carotid artery; however, manipulation with mild atherosclerotic disease resulted in no change in blood flow (50). These studies suggest that manipulation does not result in greater strain to cervical arteries than daily activity, does not result in changes in cervical blood flow in otherwise healthy adults, and only some evidence from animal studies suggests that significant atherosclerotic disease may be a contraindication.

Correlation, Relative Risk and Screening

<h4>Correlation or Causation:</h4>
More research is needed investigating whether adverse events correlated with manipulations are evidence of <a id="etiology" data-tip="1490" target="_blank" href="/glossary-term/etiology" class="glossary">causation</a> or the result of attempted treatment for serious pathology in progress. A review by Haneline et al. demonstrated that a strong correlation between cervical manipulation and internal carotid artery dissection could not be made due to the rarity of cases and the common use of manipulations for treatment. This publication also asserted the idea that in almost all cases no attempt was made at ruling out factors such as <a id="connective-tissue-cell" data-tip="1368" target="_blank" href="/glossary-term/connective-tissue-cell" class="glossary">connective tissue</a> aberrations, underlying arteriopathy, coexistent infection, and major differences in the way the techniques were performed by different practitioners/professions (51). Cassidy et al. performed a case review of 818 vertebrobasilar arteries (VBA) strokes hospitalized from Ontario hospitals between 4/1/1993 - 3/31/2002 from a population of more than 100 million people. Individuals younger than 45 years old were three times more likely to have seen a chiropractor or a primary care physician prior to stroke when compared to controls. This study strongly suggests that VBA stroke following chiropractic care is the result of patients attempting to seek treatment for dissection in progress, and/or that chiropractic care is no riskier than physician care. As mentioned above, Smith et al. asserted that manipulative therapy was an independent risk factor for vertebral artery dissection; however, the conclusion is questionable. The researchers searched hospital patient records for 5 years to identify evidence of cervical arterial dissection (CAD) occurring under the age of 60, demonstrating that individuals in the CAD group were 11% more likely to have had cervical manipulation than controls, but were also 36% more likely to have had neck pain than controls. This study likely implies that neck pain is strongly correlated with CAD and without a comparison of the risk of other interventions to manipulate the data on manipulations is cherry-picked, and/or the researchers failed to develop a useful matched participant pool (i.e. participants with neck pain who did not receive manipulations) (9). Haldeman et al. performed a case series of reported strokes, cerebral artery dissections, and cervical spine manipulation therapy, noting that 92% of cases presented with a history of head and/or neck pain, and 25% cases presented with a sudden onset of new and unusual headache and neck pain symptoms that are often associated with other neurological symptoms that may represent a dissection in progress (53). In summary, these studies suggest that the correlation between cervical artery dissection and manipulation/chiropractic care may be the result of patients seeking treatment for dissection in progress, and/or that manipulations/chiropractic care is no riskier than seeking care from a physician.
<h4>Relative Risk</h4>
A consideration that is often overlooked when debating the merits of manipulation, is the risk of adverse events relative to other treatments for similar conditions. Hurwitz et al. performed a survey study, receiving 280 adverse event questionnaire responses from 960 eligible patients, suggesting that most adverse events were mild discomfort including increased pain or headache, manipulations resulted in more adverse events than mobilizations, and adverse events resulted in a slight decrease in patient satisfaction and outcomes (54). A <a id="prospective-study" data-tip="1414" target="_blank" href="/glossary-term/prospective-study" class="glossary">prospective study</a> by Rubenstein et al. may demonstrate that the benefits of chiropractic care outweigh the risks, with the majority of neck pain patients exhibiting complete resolution of symptoms by the fourth session, 2/3rds exhibiting complete resolution at 3 and 12 months, less than 30% reporting any complaints following treatment, less than 8% reporting symptoms that could be interpreted as neurological, no complaints that could be considered serious, and only 1% of patients reported feeling worse at 3 and 12 months (55). When manipulations and chiropractic care are compared to physician intervention, the relative risks are sobering. As mentioned above, a case review by Cassidy et al. strongly suggested that VBA stroke following chiropractic care is the result of patients attempting to seek treatment for a dissection in progress, and/or that the risks following chiropractic care are similar to the risks following physician care (52). A study by Whedon et al. demonstrated the cumulative probability of injury in a group of 66 - 99yo Medicare Part B beneficiaries was 40 incidents/100,000 for a <a id="cohort-study" data-tip="1416" target="_blank" href="/glossary-term/cohort-study" class="glossary">cohort</a> receiving care from chiropractors, and 153 incidents/100,000 subjects in the primary care <a id="cohort-study" data-tip="1416" target="_blank" href="/glossary-term/cohort-study" class="glossary">cohort</a> (56). Dabbs et al. demonstrated that the best evidence indicates that NSAIDs are several 100 times more dangerous than cervical manipulations, and there is no evidence that NSAIDs are any more effective than manipulation for neck pain (57). These studies suggest that manipulations are effective for improving both short-term and long-term outcomes, serious adverse effects are exceedingly rare, and current best evidence suggests chiropractic care and manipulations are likely safer than physician care or NSAIDs (for <a id="relevance" data-tip="1505" target="_blank" href="/glossary-term/relevance" class="glossary">relevant</a> orthopedic issues). Some evidence suggests that mobilizations result in slightly fewer adverse reactions than manipulations; therefore, mobilizations may be recommended for patients who exhibit signs that may increase their risk of adverse effects

Pre-manipulative Screening
Some organizations have called for the ubiquitous use of <a href="https://brentbrookbush.com/online-exam/special-tests-upper-cervical-instability-and-vertebrobasilar-insufficiency-vbi-tests-final-exam/" target="_blank" rel="noopener">special tests for upper cervical spine </a><a id="stability" data-tip="1193" target="_blank" href="/glossary-term/stability" class="glossary">instability</a> and vertebrobasilar insufficiency (VBI) prior to performing cervical mobilizations or manipulations, despite any evidence that these <a id="assessment" data-tip="1480" target="_blank" href="/glossary-term/assessment" class="glossary">assessments</a> are sufficiently accurate to effectively screen for at-risk patients. As mentioned above, Magarey et al. published a survey study by Musculoskeletal Physiotherapy Australia with recommendations, revisions, and new clinical guidelines. The use of VBI and upper cervical <a id="stability" data-tip="1193" target="_blank" href="/glossary-term/stability" class="glossary">instability</a> special tests were recommended, despite the surveyed professionals responding that there was no evidence that these screening tools are effective for identifying at-risk individuals, the testing itself takes a significant amount of time that could be spent on more effective interventions, and the tests themselves may suggest responsibility that could lead to complex legal issues if a severe event does occur (4). Note, evidence of complex legal issues has been demonstrated in a previously mentioned review by Boucher et al. of 6 court cases in Canada with rulings that implied chiropractors were responsible for adverse events following manipulation; and further, that manipulations were the cause of injury (3). Barker et al. published guidelines representing the Manipulation Association of Chartered Physiotherapists and the Society of Orthopaedic Medicine (United Kingdom) that recommend vertebrobasilar insufficiency (VBI) testing in addition to subjective <a id="assessment" data-tip="1481" target="_blank" href="/glossary-term/assessment" class="glossary">evaluation</a>, but the publication was supported exclusively by secondary references, mostly editorials, with no attempt to review original research investigating the <a id="reliability" data-tip="1515" target="_blank" href="/glossary-term/reliability" class="glossary">reliability</a>, <a id="sensitivity" data-tip="1226" target="_blank" href="/glossary-term/sensitivity" class="glossary">sensitivity</a>, and <a id="specificity" data-tip="1223" target="_blank" href="/glossary-term/specificity" class="glossary">specificity</a> of VBI tests (58). A review by Chaibi et al. was the only review to develop a risk <a id="assessment" data-tip="1478" target="_blank" href="/glossary-term/assessment" class="glossary">assessment</a> based on available evidence, resulting in a subjective <a id="assessment" data-tip="1478" target="_blank" href="/glossary-term/assessment" class="glossary">assessment</a> questionnaire that intended to identify symptoms that would indicate a serious adverse event, or cervical artery dissection in progress (59). Questionnaires like this may be a rationale addition to <a id="assessment" data-tip="1478" target="_blank" href="/glossary-term/assessment" class="glossary">assessment</a> protocols, and they could be added to an online intake process that occurred prior to a session with the intent of preserving treatment time. These publications demonstrate
Research investigating the <a id="accuracy" data-tip="1218" target="_blank" href="/glossary-term/accuracy" class="glossary">accuracy</a> and <a id="reliability" data-tip="1515" target="_blank" href="/glossary-term/reliability" class="glossary">reliability</a> of VBI and upper cervical <a id="stability" data-tip="1193" target="_blank" href="/glossary-term/stability" class="glossary">instability</a> testing demonstrates moderate to poor <a id="sensitivity" data-tip="1226" target="_blank" href="/glossary-term/sensitivity" class="glossary">sensitivity</a> and <a id="reliability" data-tip="1515" target="_blank" href="/glossary-term/reliability" class="glossary">reliability</a>. A systematic review by Hutting et al. (including many of the studies discussed in this section) demonstrated a wide range of sensitives (0.19 - 0.88) for the Sharp-Purser <a id="assessment" data-tip="1482" target="_blank" href="/glossary-term/assessment" class="glossary">test</a>, with most studies reporting <a id="sensitivity" data-tip="1226" target="_blank" href="/glossary-term/sensitivity" class="glossary">sensitivity</a> (0.69, 0.44, 0.19) too low to be considered a viable screen prior to manual therapy, especially in consideration of the rarity of serious adverse effects. Additional tests were also covered in the 5 studies reviewed; however, the Sharp-Purser <a id="assessment" data-tip="1482" target="_blank" href="/glossary-term/assessment" class="glossary">test</a> was the only <a id="assessment" data-tip="1482" target="_blank" href="/glossary-term/assessment" class="glossary">test</a> investigated in multiple studies (60). An older study by Mathews et al. determined that the Sharp-Purser <a id="assessment" data-tip="1482" target="_blank" href="/glossary-term/assessment" class="glossary">test</a> had zero utility for identifying upper cervical <a id="stability" data-tip="1193" target="_blank" href="/glossary-term/stability" class="glossary">instability</a> in a group of rheumatoid arthritis patients, with diagnosis only being positively correlated with imaging and the palate sign (palpation of the <a id="posterior" data-tip="1565" target="_blank" href="/glossary-term/posterior" class="glossary">posterior</a> pharyngeal wall) (61). Uitvlugt et al. investigated the <a id="accuracy" data-tip="1218" target="_blank" href="/glossary-term/accuracy" class="glossary">accuracy</a> of the Sharp-Pursur <a id="assessment" data-tip="1482" target="_blank" href="/glossary-term/assessment" class="glossary">test</a> in comparison to imaging with a group of 100 rheumatoid arthritis patients. The findings demonstrated 88% <a id="sensitivity" data-tip="1226" target="_blank" href="/glossary-term/sensitivity" class="glossary">sensitivity</a>, and 96% <a id="specificity" data-tip="1223" target="_blank" href="/glossary-term/specificity" class="glossary">specificity</a>, but only when subluxation was more than 4 mm (62). Similarly, Forrester et al. investigated the <a id="accuracy" data-tip="1218" target="_blank" href="/glossary-term/accuracy" class="glossary">accuracy</a> of the Sharp-Purser <a id="assessment" data-tip="1482" target="_blank" href="/glossary-term/assessment" class="glossary">test</a> on rheumatoid arthritis patients, noting a <a id="sensitivity" data-tip="1226" target="_blank" href="/glossary-term/sensitivity" class="glossary">sensitivity</a> of 0.43, <a id="specificity" data-tip="1223" target="_blank" href="/glossary-term/specificity" class="glossary">specificity</a> of 0.77, positive <a id="predictive-values" data-tip="1738" target="_blank" href="/glossary-term/predictive-values" class="glossary">predictive value</a> of 0.34, and negative <a id="predictive-values" data-tip="1738" target="_blank" href="/glossary-term/predictive-values" class="glossary">predictive value</a> of 0.89. (63). These studies suggest that these <a id="assessment" data-tip="1480" target="_blank" href="/glossary-term/assessment" class="glossary">assessments</a> may be useful for diagnosis, but resulted in far too many false negatives to be considered a <a id="reliability" data-tip="1795" target="_blank" href="/glossary-term/reliability" class="glossary">reliable</a> screen for at-risk patients. Further, we may expect that these studies have exaggerated sensitivities and positive <a id="predictive-values" data-tip="1219" target="_blank" href="/glossary-term/predictive-values" class="glossary">predictive values</a> and that the rate of false negatives would be higher in the general public, as research has demonstrated rheumatoid arthritis patients have a higher prevalence of upper cervical <a id="stability" data-tip="1193" target="_blank" href="/glossary-term/stability" class="glossary">instability</a>. Cattrysse et al. investigated the <a id="reliability" data-tip="1515" target="_blank" href="/glossary-term/reliability" class="glossary">reliability</a> and <a id="accuracy" data-tip="1218" target="_blank" href="/glossary-term/accuracy" class="glossary">accuracy</a> of three tests (<a id="lateral" data-tip="1567" target="_blank" href="/glossary-term/lateral" class="glossary">lateral</a> displacement <a id="assessment" data-tip="1482" target="_blank" href="/glossary-term/assessment" class="glossary">test</a>, the Sharp-Purser <a id="assessment" data-tip="1482" target="_blank" href="/glossary-term/assessment" class="glossary">test</a>, and the upper cervical flexion <a id="assessment" data-tip="1482" target="_blank" href="/glossary-term/assessment" class="glossary">test</a>), performed by four independent therapists, on 11 children with Down&apos;s syndrome. Note, Down&apos;s syndrome children also have a much higher prevalence of upper cervical <a id="stability" data-tip="1193" target="_blank" href="/glossary-term/stability" class="glossary">instability</a> than the general public. The findings suggest that these tests had poor intra-therapist <a id="reliability" data-tip="1515" target="_blank" href="/glossary-term/reliability" class="glossary">reliability</a>, and almost no inter-therapist <a id="reliability" data-tip="1515" target="_blank" href="/glossary-term/reliability" class="glossary">reliability</a> (64). Kaale et al. investigated the agreement between MRI results and special tests for laxity of the alar ligament, transverse ligaments, tectorial membrane, and <a id="posterior" data-tip="1565" target="_blank" href="/glossary-term/posterior" class="glossary">posterior</a> atlantooccipital membranes for 90 patients with diagnosed whiplash-associated disorders (higher likelihood of ligament/membrane damage than the general public) and 30 patients without a related diagnosis. The results suggest that testing this population with the grades combined (0-1 = normal, 2-3 = <a id="hypermobility" data-tip="1679" target="_blank" href="/glossary-term/hypermobility" class="glossary">hypermobile</a>) resulted in good agreement (65). Cote et al. investigated the <a id="sensitivity" data-tip="1226" target="_blank" href="/glossary-term/sensitivity" class="glossary">sensitivity</a>, <a id="specificity" data-tip="1223" target="_blank" href="/glossary-term/specificity" class="glossary">specificity</a>, and <a id="predictive-values" data-tip="1219" target="_blank" href="/glossary-term/predictive-values" class="glossary">predictive values</a> of the extension-rotation <a id="assessment" data-tip="1482" target="_blank" href="/glossary-term/assessment" class="glossary">test</a> to identify interrupted vertebrobasilar blood flow, when compared to Doppler ultrasound, in 30 patients with dizziness brought on by the <a id="assessment" data-tip="1482" target="_blank" href="/glossary-term/assessment" class="glossary">test</a>. The <a id="sensitivity" data-tip="1226" target="_blank" href="/glossary-term/sensitivity" class="glossary">sensitivity</a> of the <a id="assessment" data-tip="1482" target="_blank" href="/glossary-term/assessment" class="glossary">test</a> was 0 and the positive <a id="predictive-values" data-tip="1738" target="_blank" href="/glossary-term/predictive-values" class="glossary">predictive value</a> was 0, suggesting this <a id="assessment" data-tip="1482" target="_blank" href="/glossary-term/assessment" class="glossary">test</a> is useless as a screen. Note, <a id="specificity" data-tip="1223" target="_blank" href="/glossary-term/specificity" class="glossary">specificity</a> was moderate, and negative <a id="predictive-values" data-tip="1738" target="_blank" href="/glossary-term/predictive-values" class="glossary">predictive value</a> ranged between fair and good which could imply the tests have some utility for diagnosis (66). In summary, the <a id="reliability" data-tip="1515" target="_blank" href="/glossary-term/reliability" class="glossary">reliability</a>, <a id="sensitivity" data-tip="1226" target="_blank" href="/glossary-term/sensitivity" class="glossary">sensitivity</a>, and positive <a id="predictive-values" data-tip="1738" target="_blank" href="/glossary-term/predictive-values" class="glossary">predictive value</a> of VBI and upper cervical <a id="stability" data-tip="1193" target="_blank" href="/glossary-term/stability" class="glossary">instability</a> testing only reach a level of &quot;fair&quot; when the criteria for a positive result is identified by a relatively large change (4mm or combining multiple grades), and/or these tests are performed on a patient population with a much higher than normal prevalence of positive results. Many studies demonstrated zero or poor sensitivity/positive <a id="predictive-values" data-tip="1738" target="_blank" href="/glossary-term/predictive-values" class="glossary">predictive value</a>, even when used with high prevalence populations, suggesting that these tests cannot be trusted to screen the general population for individuals at-risk for exceedingly rare events. Last, it should also be noted that there is no evidence that serious adverse events are correlated with a positive result on VBI or upper cervical <a id="stability" data-tip="1193" target="_blank" href="/glossary-term/stability" class="glossary">instability</a> testing, with or without the addition of manipulations.

<ol>
 <li>Puentedura, E. J., Slaughter, R., Reilly, S., Ventura, E., &amp; Young, D. (2017). Thrust joint manipulation utilization by US physical therapists. Journal of Manual &amp; Manipulative Therapy,&nbsp;25(2), 74-82.</li>
 <li>Hincapi&eacute;, C. A., Cassidy, J. D., C&ocirc;t&eacute;, P., Rampersaud, Y. R., Jadad, A. R., &amp; Tomlinson, G. A. (2018). Chiropractic spinal manipulation and the risk for acute lumbar disc herniation: a belief elicitation study.&nbsp;European Spine Journal,&nbsp;27(7), 1517-1525.</li>
 <li>Boucher, P., &amp; Robidoux, S. (2014). Lumbar disc herniation and cauda equina syndrome following spinal manipulative therapy: a review of six court decisions in Canada.&nbsp;Journal of forensic and legal medicine,&nbsp;22, 159-169.
 <ul>
 <li>Cervical Spine: Survey Data and Systematic Reviews</li>
 </ul>
 </li>
 <li>Magarey, M. E., Rebbeck, T., Coughlan, B., Grimmer, K., Rivett, D. A., &amp; Refshauge, K. (2004). Pre-manipulative testing of the cervical spine review, revision and new clinical guidelines.&nbsp;Manual Therapy,&nbsp;9(2), 95-108.</li>
 <li>Stevinson, C., Honan, W., Cooke, B., &amp; Ernst, E. (2001). Neurological complications of cervical spine manipulation.&nbsp;Journal of the Royal Society of Medicine,&nbsp;94(3), 107-110.</li>
 <li>Haldeman, S., Carey, P., Townsend, M., &amp; Papadopoulos, C. (2002). Clinical perceptions of the risk of vertebral artery dissection after cervical manipulation: the effect of referral bias.&nbsp;The Spine Journal,&nbsp;2(5), 334-342.</li>
 <li>Kranenburg, H. A., Schmitt, M. A., Puentedura, E. J., Luijckx, G. J., &amp; Van der Schans, C. P. (2017). Adverse events associated with the use of cervical spine manipulation or mobilization and patient characteristics: a systematic review.&nbsp;Musculoskeletal science and practice,&nbsp;28, 32-38.</li>
 <li>Rothwell, D. M., Bondy, S. J., &amp; Williams, J. I. (2001). Chiropractic manipulation and stroke.&nbsp;Stroke,&nbsp;32(5), 1054-1063.</li>
 <li>Smith, W. S., Johnston, S. C., Skalabrin, E. J., Weaver, M., Azari, P., Albers, G. W., &amp; Gress, D. R. (2003). Spinal manipulative therapy is an independent risk factor for vertebral artery dissection.&nbsp;Neurology,&nbsp;60(9), 1424-1428.</li>
 <li>Haldeman, S., Kohlbeck, F. J., &amp; McGregor, M. (2002). Unpredictability of cerebrovascular ischemia associated with cervical spine manipulation therapy: a review of sixty-four cases after cervical spine manipulation.&nbsp;Spine,&nbsp;27(1), 49-55.
 <ol>
 <li>Thoracic Spine and Lumbar Spine: Survey Data and Systematic Reviews</li>
 </ol>
 </li>
 <li>Rydell, N., &amp; R&auml;f, L. (1999). Spinal manipulation--treatment associated with a high risk of complications.&nbsp;Lakartidningen,&nbsp;96(34), 3536-3540.</li>
 <li>Puentedura, E. J., &amp; O'Grady, W. H. (2015). Safety of thrust joint manipulation in the thoracic spine: a systematic review.&nbsp;Journal of Manual &amp; Manipulative Therapy,&nbsp;23(3), 154-161.</li>
 <li>Senstad, O., Leboeuf-Yde, C., &amp; Borchgrevink, C. (1996). Predictors of side effects to spinal manipulative therapy.&nbsp;Journal of manipulative and physiological therapeutics,&nbsp;19(7), 441-445.</li>
 <li>Hebert, J. J., Stomski, N. J., French, S. D., &amp; Rubinstein, S. M. (2015). Serious adverse events and spinal manipulative therapy of the low back region: a systematic review of cases.&nbsp;Journal of Manipulative and Physiological therapeutics,&nbsp;38(9), 677-691.</li>
 <li>Kim, H. S., Ha, J. W., Park, J. O., Park, H. W., Han, D. Y., &amp; Hur, J. H. (1998). Ruptured lumbar disc in patients undergoing manipulation of the lumbar spine.&nbsp;Journal of the Korean Orthopaedic Association,&nbsp;33(5), 1326-1333.</li>
 <li>Oliphant, D. (2004). Safety of spinal manipulation in the treatment of lumbar disk herniations: a systematic review and risk assessment.&nbsp;Journal of Manipulative and Physiological Therapeutics,&nbsp;27(3), 197-210.</li>
 <li>Hincapi&eacute;, C. A., Tomlinson, G. A., C&ocirc;t&eacute;, P., Rampersaud, Y. R., Jadad, A. R., &amp; Cassidy, J. D. (2018). Chiropractic care and risk for acute lumbar disc herniation: a population-based self-controlled case series study.&nbsp;European Spine Journal,&nbsp;27(7), 1526-1537.
 <ul>
 <li>Published Case Series</li>
 </ul>
 </li>
 <li>Di Fabio, R. P. (1999). Manipulation of the cervical spine: risks and benefits.&nbsp;Physical Therapy,&nbsp;79(1), 50-65</li>
 <li>Oppenheim, J. S., Spitzer, D. E., &amp; Segal, D. H. (2005). Nonvascular complications following spinal manipulation.&nbsp;The Spine Journal,&nbsp;5(6), 660-666.</li>
 <li>Hufnagel, A., Hammers, A., Sch&ouml;nle, P. W., B&ouml;hm, K. D., &amp; Leonhardt, G. (1999). Stroke following chiropractic manipulation of the cervical spine. Journal of Neurology, 246(8), 683-688.</li>
 <li>Haldeman, S., &amp; Rubinstein, S. M. (1992). Cauda equina syndrome in patients undergoing manipulation of the lumbar spine.&nbsp;Spine,&nbsp;17(12), 1469-1473.
 <ul>
 <li>Published Case Studies</li>
 </ul>
 </li>
 <li>Ruelle, A., Datti, R., &amp; Pisani, R. (1999). Thoracic epidural hematoma after spinal manipulation therapy.&nbsp;Journal of spinal disorders,&nbsp;12(6), 534-536.</li>
 <li>Hdeib, A., Goodwin, C. R., Sciubba, D., Bydon, A., Wolinsky, J. P., Witham, T., &amp; Gokaslan, Z. L. (2016). Hemorrhagic thoracic schwannoma presenting with intradural hematoma and acute paraplegia after spinal manipulation therapy.&nbsp;International journal of spine surgery,&nbsp;10, 42.</li>
 <li>Yang, Si-Dong, Qian Chen, and Wen-Yuan Ding. "Cauda Equina Syndrome Due to Vigorous Back Massage With Spinal Manipulation in a Patient With Pre-Existing Lumbar Disc Herniation: A Case Report and Literature Review."&nbsp;American journal of physical medicine &amp; rehabilitation&nbsp;97.4 (2018): e23-e26.</li>
 <li>Solheim, O., Jorgensen, J. V., &amp; Nygaard, O. P. (2007). Lumbar epidural hematoma after chiropractic manipulation for lower-back pain: case report.&nbsp;Neurosurgery,&nbsp;61(1), E170-E171.</li>
 <li>Cheng, Y. P., Lee, K. W., Lin, P. Y., Huang, A. P. H., Cheng, C. Y., Ma, H. I., &hellip; &amp; Hueng, D. Y. (2014). Full-endoscopic interlaminar removal of chronic lumbar epidural hematoma after spinal manipulation.&nbsp;Surgical Neurology International,&nbsp;5.</li>
 <li>Morandi, X., Riffaud, L., Houedakor, J., Amlashi, S. F., Brassier, G., &amp; Gallien, P. (2004). Caudal spinal cord ischemia after lumbar vertebral manipulation.&nbsp;Joint Bone Spine,&nbsp;71(4), 334-337</li>
 <li>Kornberg, E. (1988). Lumbar artery aneurysm with acute aortic occlusion resulting from chiropractic manipulation: a case report.&nbsp;Surgery,&nbsp;103(1), 122-124.
 <ul>
 <li>Non-life-threatening Adverse Effects</li>
 </ul>
 </li>
 <li>Dvoř&aacute;k, J., Loustalot, D., Baumgartner, H., &amp; Antinnes, J. A. (1993). Frequency of complications of manipulation of the spine.&nbsp;European Spine Journal,&nbsp;2(3), 136-139.</li>
 <li>Thiel, H. W., Bolton, J. E., Docherty, S., &amp; Portlock, J. C. (2007). Safety of chiropractic manipulation of the cervical spine: a prospective national survey.&nbsp;Spine,&nbsp;32(21), 2375-2378.</li>
 <li>Rothwell, D. M., Bondy, S. J., &amp; Williams, J. I. (2001). Chiropractic manipulation and stroke.&nbsp;Stroke,&nbsp;32(5), 1054-1063.</li>
 <li>Cagnie, B., Vinck, E., Beernaert, A., &amp; Cambier, D. (2004). How common are side effects of spinal manipulation and can these side effects be predicted?.&nbsp;Manual therapy,&nbsp;9(3), 151-156.</li>
 <li>Paanalahti, K., Holm, L. W., Nordin, M., Asker, M., Lyander, J., &amp; Skillgate, E. (2014). Adverse events after manual therapy among patients seeking care for neck and/or back pain: a randomized controlled trial.&nbsp;BMC musculoskeletal disorders,&nbsp;15(1), 77.
 <ul>
 <li>Professional Consensus to Classify Adverse Events</li>
 </ul>
 </li>
 <li>Kranenburg, H. A., Lakke, S. E., Schmitt, M. A., &amp; Van der Schans, C. P. (2017). Adverse events following cervical manipulative therapy: consensus on classification among Dutch medical specialists, manual therapists, and patients.&nbsp;Journal of Manual &amp; Manipulative Therapy,&nbsp;25(5), 279-287.</li>
 <li>Carnes, D., Mullinger, B., &amp; Underwood, M. (2010). Defining adverse events in manual therapies: a modified Delphi consensus study.&nbsp;Manual therapy,&nbsp;15(1), 2-6
 <ul>
 <li>Force Necessary for Tissue Failure</li>
 </ul>
 </li>
 <li>Sran, M. M., Khan, K. M., Zhu, Q., McKay, H. A., &amp; Oxland, T. R. (2004). Failure characteristics of the thoracic spine with a posteroanterior load: investigating the safety of spinal mobilization.&nbsp;Spine,&nbsp;29(21), 2382-2388.</li>
 <li>Stemper, B. D., Hallman, J. J., &amp; Peterson, B. M. (2011). An experimental study of chest compression during chiropractic manipulation of the thoracic spine using an anthropomorphic test device.&nbsp;Journal of manipulative and physiological therapeutics,&nbsp;34(5), 290-296.</li>
 <li>Triano, J., &amp; Schultz, A. B. (1997). Loads transmitted during lumbosacral spinal manipulative therapy.&nbsp;Spine,&nbsp;22(17), 1955-1964.</li>
 <li>Boonyoung, C., Kwanyuang, A., &amp; Chatpun, S. (2018, November). A finite element study of posteroanterior lumbar mobilization on elderly vertebra geometry. In&nbsp;2018 11th Biomedical Engineering International Conference (BMEiCON)&nbsp;(pp. 1-4). IEEE.
 <ul>
 <li>Structural Damage Pre and Post Manipulation</li>
 </ul>
 </li>
 <li>Ianuzzi, A., &amp; Khalsa, P. S. (2005). Comparison of human lumbar facet joint capsule strains during simulated high-velocity, low-amplitude spinal manipulation versus physiological motions.&nbsp;The Spine Journal,&nbsp;5(3), 277-290.</li>
 <li>Chrisman, O. D., Mittnacht, A., &amp; Snook, G. A. (1964). A study of the results following rotatory manipulation in the lumbar intervertebral-disc syndrome.&nbsp;JBJS,&nbsp;46(3), 517-524.
 <ul>
 <li>Cervical Manipulations Use Less Than Available Active ROM</li>
 </ul>
 </li>
 <li>Van Geyt, B., Dugailly, P. M., Klein, P., Lepers, Y., Beyer, B., &amp; Feipel, V. (2017). Assessment of in vivo 3D kinematics of cervical spine manipulation: Influence of practitioner experience and occurrence of cavitation noise.&nbsp;Musculoskeletal Science and Practice,&nbsp;28, 18-24.</li>
 <li>Liguo, Z., Minshan, F., Xunlu, Y., Shangquan, W., &amp; Jie, Y. (2017). Kinematics Analysis of Cervical Rotation-Traction Manipulation Measured by a Motion Capture System.&nbsp;Evidence-Based Complementary and Alternative Medicine,&nbsp;2017.</li>
 <li>Klein, P., Broers, C., Feipel, V., Salvia, P., Van Geyt, B., Dugailly, P. M., &amp; Rooze, M. (2003). Global 3D head&ndash;trunk kinematics during cervical spine manipulation at different levels. Clinical Biomechanics, 18(9), 827-831.</li>
 <li>Salem, W., &amp; Klein, P. (2013). In vivo 3D kinematics of the cervical spine segments during pre-manipulative positioning at the C4/C5 level.&nbsp;Manual therapy,&nbsp;18(4), 321-326.
 <ul>
 <li>Vessel Dissection and Occlusion</li>
 </ul>
 </li>
 <li>Herzog, W., Tang, C., &amp; Leonard, T. (2015). Internal carotid artery strains during high-speed, low-amplitude spinal manipulations of the neck.&nbsp;Journal of manipulative and physiological therapeutics,&nbsp;38(9), 664-671.</li>
 <li>Quesnele, J. J., Triano, J. J., Noseworthy, M. D., &amp; Wells, G. D. (2014). Changes in vertebral artery blood flow following various head positions and cervical spine manipulation.&nbsp;Journal of manipulative and physiological therapeutics,&nbsp;37(1), 22-31.</li>
 <li>Licht, P. B., Christensen, H. W., H&oslash;jgaard, P., &amp; Marving, J. (1998). Vertebral artery flow and spinal manipulation:&nbsp;a randomized, controlled and observer-blinded study.&nbsp;Journal of manipulative and physiological therapeutics,&nbsp;21(3), 141-144.</li>
 <li>Qi, J., Ping, R., Zhang, S., Xu, Y., Wu, K., &amp; Li, Y. (2019). Effects of Cervical Rotatory Manipulation (CRM) on Carotid Atherosclerosis Plaque in Vulnerability: A Histological and Immunohistochemical Study Using Animal Model.&nbsp;BioMed research international,&nbsp;2019.</li>
 <li>Guan, T., Zeng, Y., Qi, J., Qin, B., Fu, S., Wang, G., &amp; Zhang, L. (2019). Effects of Cervical Rotatory Manipulation on Internal Carotid Artery in Hemodynamics Using an Animal Model of Carotid Atherosclerosis: A Safety Study.&nbsp;Medical science monitor: international medical journal of experimental and clinical research,&nbsp;25, 2344.
 <ul>
 <li>Correlation or Causation:</li>
 </ul>
 </li>
 <li>Haneline, M. T., Croft, A. C., &amp; Frishberg, B. M. (2003). Association of internal carotid artery dissection and chiropractic manipulation.&nbsp;The Neurologist,&nbsp;9(1), 35-44.</li>
 <li>Cassidy, J. D., Boyle, E., C&ocirc;t&eacute;, P., He, Y., Hogg-Johnson, S., Silver, F. L., &amp; Bondy, S. J. (2009). Risk of vertebrobasilar stroke and chiropractic care: results of a population-based case-control and case-crossover study.&nbsp;Journal of Manipulative and Physiological Therapeutics,&nbsp;32(2), S201-S208.</li>
 <li>Haldeman, S., Kohlbeck, F. J., &amp; McGregor, M. (2002). Stroke, cerebral artery dissection, and cervical spine manipulation therapy.&nbsp;Journal of neurology,&nbsp;249(8), 1098-1104.
 <ul>
 <li>Relative Risk</li>
 </ul>
 </li>
 <li>Hurwitz, E. L., Morgenstern, H., Vassilaki, M., &amp; Chiang, L. M. (2004). Adverse reactions to chiropractic treatment and their effects on satisfaction and clinical outcomes among patients enrolled in the UCLA Neck Pain Study.&nbsp;Journal of Manipulative and physiological Therapeutics,&nbsp;27(1), 16-25.</li>
 <li>Rubinstein, S. M., Leboeuf-Yde, C., Knol, D. L., de Koekkoek, T. E., Pfeifle, C. E., &amp; van Tulder, M. W. (2007). The benefits outweigh the risks for patients undergoing chiropractic care for neck pain: a prospective, multicenter, cohort study.&nbsp;Journal of Manipulative and Physiological Therapeutics,&nbsp;30(6), 408-418.</li>
 <li>Whedon, J. M., Mackenzie, T. A., Phillips, R. B., &amp; Lurie, J. D. (2015). Risk of traumatic injury associated with chiropractic spinal manipulation in Medicare Part B beneficiaries aged 66&ndash;99.&nbsp;Spine,&nbsp;40(4), 264.</li>
 <li>Dabbs, V., &amp; Lauretti, W. J. (1995). A risk assessment of cervical manipulation vs. NSAIDs for the treatment of neck pain.&nbsp;Journal of Manipulative and Physiological Therapeutics,&nbsp;18(8), 530-536.
 <ul>
 <li>Pre-manipulative Screening</li>
 </ul>
 </li>
 <li>Barker, S., Kesson, M., Ashmore, J., Turner, G., Conway, J., &amp; Stevens, D. (2001). Guidance for pre-manipulative testing of the cervical spine.&nbsp;Physiotherapy,&nbsp;87(6), 318-321.</li>
 <li>Chaibi, A., &amp; Russell, M. B. (2019). A risk&ndash;benefit assessment strategy to exclude cervical artery dissection in spinal manual-therapy: a comprehensive review.&nbsp;Annals of medicine,&nbsp;51(2), 118-127.</li>
 <li>Hutting, N., Scholten-Peeters, G. G., Vijverman, V., Keesenberg, M. D., &amp; Verhagen, A. P. (2013). Diagnostic accuracy of upper cervical spine instability tests: a systematic review.&nbsp;Physical&nbsp;therapy,&nbsp;93(12), 1686-1695.</li>
 <li>Mathews, J. A. (1969). Atlanto-axial subluxation in rheumatoid arthritis.&nbsp;Annals of the Rheumatic Diseases,&nbsp;28(3), 260.</li>
 <li>Uitvlugt, G., &amp; Indenbaum, S. (1988). Clinical assessment of atlantoaxial instability using the sharp‐purser test.&nbsp;Arthritis &amp; Rheumatism: Official Journal of the American College of Rheumatology,&nbsp;31(7), 918-922.</li>
 <li>Forrester, G. A., &amp; Barlas, P. (1999). Reliability and Validity of the Sharp-Purser Test in the Assessment of Atlanto-axial Instability in Patients with Rheumatoid Arthritis.&nbsp;Physiotherapy,&nbsp;85(7), 376.</li>
 <li>Cattrysse, E., Swinkels, R. A. H. M., Oostendorp, R. A. B., &amp; Duquet, W. (1997). Upper cervical instability: are clinical tests reliable?. Manual Therapy,&nbsp;2(2), 91-97.</li>
 <li>Kaale, B. R., Krakenes, J., Albrektsen, G., &amp; Wester, K. (2008). Clinical assessment techniques for detecting ligament and membrane injuries in the upper cervical spine region&mdash;a comparison with MRI results. Manual therapy, 13(5), 397-403.</li>
 <li>Cote, P., Kreitz, B. G., Cassidy, J. D., &amp; Thiel, H. (1996). The validity of the extension-rotation test as a clinical screening procedure before neck manipulation: a secondary analysis. Journal of Manipulative and Physiological Therapeutics, 19(3), 159-164.</li>
</ol>

Bibliography

&copy; 2021 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>

Any Questions, Concerns or Recommendations?

Please contact us through the
Support Page

Legal

Social

Joint Mobilizations and Manipulations: Risk of Adverse Events

Any Questions, Concerns or Recommendations? Please contact us through the Support Page

Legal

Social

Any Questions, Concerns or Recommendations?

Please contact us through the
Support Page