Manual therapy and cervical arterial dysfunction, directions for the future: a clinical perspective

Spinal manipulation and perineural electrical dry needling in patients with cervicogenic headache: a multicenter randomized clinical trial

BACKGROUND CONTEXT

Spinal manipulation, spinal mobilization, and exercise are commonly used in individuals with cervicogenic headache (CH). Dry needling is being increasingly used in the management of CH. However, questions remain about the effectiveness of these therapies and how they compare to each other.

PURPOSE

The present study aims to compare the combined effects of spinal manipulation and dry needling with spinal mobilization and exercise on pain and disability in individuals with CH.

STUDY DESIGN/SETTING

Randomized, multicenter, parallel-group trial.

PATIENT SAMPLE

One hundred forty-two patients (n=142) with CH from 13 outpatient clinics in 10 different states were recruited over a 36-month period.

OUTCOME MEASURES

The primary outcome was headache intensity as measured by the Numeric Pain Rating Scale. Secondary outcomes included headache frequency and duration, disability (Neck Disability Index), medication intake, and the Global Rating of Change (GROC). Follow-up assessments were taken at 1 week, 4 weeks, and 3 months.

METHODS

Patients were randomized to receive upper cervical and upper thoracic spinal manipulation plus electrical dry needling (n=74) or upper cervical and upper thoracic spinal mobilization and exercise (n=68). In addition, the mobilization group also received a program of craniocervical and peri-scapular resistance exercises; whereas, the spinal manipulation group also received up to eight sessions of perineural electrical dry needling. The treatment period for both groups was 4 weeks. The trial was prospectively registered at ClinicalTrials.gov (NCT02373605). Drs Dunning, Butts and Young are faculty within the AAMT Fellowship and teach postgraduate courses in spinal manipulation, spinal mobilization, dry needling, exercise and differential diagnosis. The other authors declare no conflicts of interest. None of the authors received any funding for this study.

RESULTS

The 2 × 4 analysis of covariance revealed that individuals with CH who received thrust spinal manipulation and electrical dry needling experienced significantly greater reductions in headache intensity (F=23.464; p<.001), headache frequency (F=13.407; p<.001), and disability (F=10.702; p<.001) than those who received nonthrust mobilization and exercise at a 3-month follow-up. Individuals in the spinal manipulation and electrical dry needling group also experienced shorter duration of headaches (p<.001) at 3 months. Based on the cutoff score of ≥+5 on the GROC, significantly (X²=54.840; p<.001) more patients (n=57, 77%) within the spinal manipulation and electrical dry needling group achieved a successful outcome compared to the mobilization and exercise group (n=10, 15%) at 3-month follow-up. Between-groups effect sizes were large (0.94<standardized mean score difference<1.25) in all outcomes in favor of the spinal manipulation and electrical dry needling group at 3 months. In addition, significantly (X²=29.889; p<.001) more patients in the spinal manipulation and electrical dry needling group (n=49, 66%) completely stopped taking medication for their pain compared to the spinal mobilization and exercise group (n=14, 21%) at 3 months.

CONCLUSION

Upper cervical and upper thoracic high-velocity low-amplitude thrust spinal manipulation and electrical dry needling were shown to be more effective than nonthrust mobilization and exercise in patients with CH, and the effects were maintained at 3 months.

Differences in force-time parameters and electromyographic characteristics of two high-velocity, low-amplitude spinal manipulations following one another in quick succession

BACKGROUND

Spinal manipulative therapy is an effective treatment for neck pain. However, the mechanisms underlying its clinical efficacy are not fully understood. Previous studies have not systematically compared force-time parameters and electromyographic responses associated with spinal manipulation. In this study, force-time parameters and electromyographic characteristics associated with multiple manual high-velocity, low-amplitude cervical and upper thoracic spinal manipulations were investigated. The purpose of this analysis was to compare the force-time parameters and electromyographic characteristics between two spinal manipulations delivered following one another in quick succession if the first thrust was not associated with an audible cavitation.

METHODS

Nine asymptomatic and eighteen symptomatic participants received six Diversified-style spinal manipulations to the cervical and upper thoracic spines during data collected February 2018 to September 2019. Peak force, rate of force application and thrust duration were measured using a pressure pad. Bipolar surface electrodes were used to measure the electromyographic responses and reflex delay times in sixteen neck, back and limb outlet muscles bilaterally. Differences in force-time parameters and electromyographic data were analyzed between the first and second thrust.

RESULTS

Fifty-two spinal manipulations were included in this analysis. Peak force was greater (p < 0.001) and rate of force application faster (p < 0.001) in the second thrust. Furthermore, peak electromyographic responses were higher following the second thrust in asymptomatic (p < 0.001) and symptomatic (p < 0.001) subjects. Also, electromyographic delays were shorter in the symptomatic compared to the asymptomatic participants for the second thrust (p = 0.039). There were no adverse patient events.

CONCLUSION

When a second manipulation was delivered because there was not audible cavitation during the first thrust, the second thrust was associated with greater treatment forces and faster thrust rates. Peak electromyographic responses were greater following the second thrust.

Proposing a new algorithm for premanipulative testing in physical therapy practice

In the field of physical therapy, there is debate as to the clinical utility of premanipulative vascular assessments. Cervical artery dysfunction (CAD) risk assessment involves a multi-system approach to differentiate between spontaneous versus mechanical events. The purposes of this inductive analysis of the literature are to discuss the link between cervical spine manipulation (CSM) and CAD, to examine the literature on premanipulative vascular tests, and to suggest an optimal sequence of premanipulative testing based on the differentiation of a spontaneous versus mechanical vascular event. Knowing what premanipulative vascular tests assess and the associated clinical application facilitates an evidence-informed decision for clinical application of vascular assessment before CSM.

Comparing the range of musculoskeletal therapies applied by physical therapists with postgraduate qualifications in manual therapy in patients with non-specific neck pain with international guidelines and recommendations: An observational study

The aim of this study is to compare Dutch usual care musculoskeletal therapy in patients with non-specific neck pain with recommendations from international clinical practice guidelines. Physical therapy is diverse, as it may consist of exercise, massage, advice, and other modalities. Physical therapists with post graduate qualifications in manual therapy (MT) may additionally apply spinal thrust manipulation or non-thrust mobilization techniques to treat neck pain. It is important that, in the absence of a Dutch clinical guideline for the treatment of patients with neck pain, musculoskeletal therapists use the available recommendations from international clinical practice guidelines when treating patients with neck pain. One updated clinical practice guideline was identified (Blanpied, 2017), a report from the Task Force on Neck Pain (Guzman et al., 2008) and the IFOMPT International Framework for Examination of the Cervical Region for potential of Cervical Arterial Dysfunction prior to Orthopaedic Manual Therapy Intervention (Rushton et al., 2014). At baseline 1193 patients are included and data with regard to pain, disability, fear avoidance, expectations and applied treatment modalities are gathered. Outcome is measured using the Global Perceived Effect questionnaire. Results show that patients with acute neck pain are treated significantly more often with manipulation compared to patients with sub-acute or chronic neck pain (p < .000) and younger patients are treated with manipulation more often than older patients (p < .000). In the presence of comorbidity, the preference of spinal manipulation seems to diminish, in favour of mobilization and exercise. Almost every patient receives multimodal therapy (94.3%) and spinal manipulation and mobilization are rarely used as a stand-alone treatment (4.5% and 0.8%). Dutch musculoskeletal therapists choose treatment strategies that correspond with recommendations from international guidelines.

Factors associated with cervical arterial dysfunction: a survey of physical therapist educators in the United States

Objectives: The purpose of this study was to identify the key constructs associated with symptom description and behavior, natural history of complaints, and previous medical history of cervical arterial dysfunction (CAD) according to a panel of physical therapist (PT) educators. Methods: An electronic survey was conducted of licensed PT educators currently involved in musculoskeletal physical therapy education within a credentialed program. Survey prompts queried educators to list the subjective and objective items associated with CAD, in open-text format. Responses were coded to identify unique themes (constructs). Principal axis factor analysis with Varimax rotation was performed to identify underlying constructs associated with CAD according to the panel of educators. Results: Seventy-two educators completed the survey (24.2% response rate) resulting in 50 identified unique items through thematic coding. Factor analysis (Kaiser-Meyer-Olkin measure of sampling adequacy = .679, Bartlett's test of sphericity (x ²(351) = 1129.06. p < .001), resulted in a four-factor solution: '5Ds and 3 Ns,' 'Other Neurological Findings,' 'Signs & Symptoms in Rotation and/or Extension,' and 'General Health.' Discussion: According to the PT educators in this study, the factors associated with CAD appear to reflect the IFOMPT guidelines. The responses and subsequent factor analysis demonstrate the lack of any one clinical finding for the identification of CAD in a patient with neck pain. Level of Evidence: V.

Reflex Responses of Neck, Back, and Limb Muscles to High-Velocity, Low-Amplitude Manual Cervical and Upper Thoracic Spinal Manipulation of Asymptomatic Individuals-A Descriptive Study

OBJECTIVE

The purpose of this research was to determine the extent of reflex responses after spinal manipulative therapy (SMT) of the cervical and upper thoracic spine.

METHODS

Eleven asymptomatic participants received 6 commonly used SMTs to the cervical and upper thoracic spine. Bipolar surface electromyography electrodes were used to measure reflex responses of 16 neck, back, and proximal limb muscles bilaterally. The percentage of occurrence and the extent of reflex responses of these muscles were determined.

RESULTS

Reflex responses after cervical SMT were typically present in all neck and most back muscles, whereas responses in the outlets to the arm and leg were less frequent. This trend was similar, although decreased in magnitude, after thoracic SMT.

CONCLUSION

Reflex responses were greatest after upper cervical SMT and lowest with thoracic SMT.

A risk-benefit assessment strategy to exclude cervical artery dissection in spinal manual-therapy: a comprehensive review

Cervical artery dissection refers to a tear in the internal carotid or the vertebral artery that results in an intramural haematoma and/or an aneurysmal dilatation. Although cervical artery dissection is thought to occur spontaneously, physical trauma to the neck, especially hyperextension and rotation, has been reported as a trigger. Headache and/or neck pain is the most common initial symptom of cervical artery dissection. Other symptoms include Horner's syndrome and lower cranial nerve palsy. Both headache and/or neck pain are common symptoms and leading causes of disability, while cervical artery dissection is rare. Patients often consult their general practitioner for headache and/or neck pain, and because manual-therapy interventions can alleviate headache and/or neck pain, many patients seek manual therapists, such as chiropractors and physiotherapists. Cervical mobilization and manipulation are two interventions that manual therapists use. Both interventions have been suspected of being able to trigger cervical artery dissection as an adverse event. The aim of this review is to provide an updated step-by-step risk-benefit assessment strategy regarding manual therapy and to provide tools for clinicians to exclude cervical artery dissection. Key messages Cervical mobilization and/or manipulation have been suspected to be able to trigger cervical artery dissection (CAD). However, these assumptions are based on case studies which are unable to established direct causality. The concern relates to the chicken and the egg discussion, i.e. whether the CAD symptoms lead the patient to seek cervical manual-therapy or whether the cervical manual-therapy provoked CAD along with the non-CAD presenting complaint. Thus, instead of proving a nearly impossible causality hypothesis, this study provide clinicians with an updated step-by-step risk-benefit assessment strategy tool to (a) facilitate clinicians understanding of CAD, (b) appraise the risk and applicability of cervical manual-therapy, and (c) provide clinicians with adequate tools to better detect and exclude CAD in clinical settings.

Knowledge and pre-thoracic spinal thrust manipulation examination: a survey of current practice in the UK

OBJECTIVES

The perceived relative safety of thoracic thrust joint manipulation (TTJM) has contributed to evidence supporting its use. Yet, TTJM is not without risk, where transient side effects (SE) and severe adverse events (AE) have been documented. With evidence supporting the importance of prethrust examination in reducing AE in other spinal regions this study investigated TTJM knowledge and pre-TTJM examination. Method: An e-survey, informed by existing evidence and expertise was designed and piloted. Eligibility criteria: UK-trained physiotherapists who use TTJM. Recruitment via professional networks and social media from December 2016 to February 2017. Data analysis included descriptive analyses (means, standard deviation and frequencies/central tendencies), and content analysis (themes and frequencies) for free text data. Results: From 306 responses, the sample comprised 146 (53%) males, mean (SD) age 36.37(8.68) years, with 12.88(8.67) years in practice, 11.07(8.14) years specialization, working in National Health Service/private practice (81%) and performing 0-5 TTJM/week (86%).

EXAMINATION

40% (n = 83) utilized pre-TTJM examination with 45% (n = 139) adapting the examination for different regions. Technique selection and effect: preferred technique was prone rotational TTJM (67%). Perception of the primary underlying effect was neurophysiological (54%), biomechanical (45%) or placebo (1%). Knowledge: Levels of agreement were found for contraindications (85%), precautions (75%), and red flags (86%) with more variability for risks including AE and SE (61%).

DISCUSSION

UK physiotherapists demonstrated good knowledge and agreement of contraindications, precautions, and red flags to TTJM. With <50% respondents utilizing pre-TTJM examination, variable knowledge of TTJM risks, and therapeutic effects of TTJM further research is required.

Considerations to improve the safety of cervical spine manual therapy

Manipulation and mobilisation of the cervical spine are well established interventions in the management of patients with headache and/or neck pain. However, their benefits are accompanied by potential, yet rare risks in terms of serious adverse events, including neurovascular insult to the brain. A recent international framework for risk assessment and management offers directions in the mitigation of this risk by facilitating sound clinical reasoning. The aim of this article is to critically reflect on and summarize the current knowledge about cervical spine manual therapy and to provide guidance for clinical reasoning for cervical spine manual therapy.

The efficacy of manual therapy and exercise for treating non-specific neck pain: A systematic review

OBJECTIVE

To review and update the evidence for different forms of manual therapy (MT) and exercise for patients with different stages of non-specific neck pain (NP).

DATA SOURCES

MEDLINE, Cochrane-Register-of-Controlled-Trials, PEDro, EMBASE.

METHOD

A qualitative systematic review covering a period from January 2000 to December 2015 was conducted according to updated-guidelines. Specific inclusion criteria only on RCTs were used; including differentiation according to stages of NP (acute - subacute [ASNP] or chronic [CNP]), as well as sub-classification based on type of MT interventions: MT1 (HVLA manipulation); MT2 (mobilization and/or soft-tissue-techniques); MT3 (MT1 + MT2); and MT4 (Mobilization-with-Movement). In each sub-category, MT could be combined or not with exercise and/or usual medical care.

RESULTS

Initially 121 studies were identified for potential inclusion. Based on qualitative and quantitative evaluation criteria, 23 RCTs were identified for review. Evidence for ASNP: MODERATE-evidence: In favour of (i) MT1 to the cervical spine (Cx) combined with exercises when compared to MT1 to the thoracic spine (Tx) combined with exercises; (ii) MT3 to the Cx and Tx combined with exercise compared to MT2 to the Cx with exercise or compared to usual medical care for pain and satisfaction with care from short to long-term. Evidence for CNP: STRONG-evidence: Of no difference of efficacy between MT2 at the symptomatic Cx level(s) in comparison to MT2 on asymptomatic Cx level(s) for pain and function. MODERATE to STRONG-evidence: In favour of MT1 and MT3 on Cx and Tx with exercise in comparison to exercise or MT alone for pain, function, satisfaction with care and general-health from short to moderate-terms. MODERATE-evidence: In favour (i) of MT1 as compared to MT2 and MT4, all applied to the Cx, for neck mobility, and pain in the very short term; (ii) of MT2 using sof-tissue-techniques to the Cx and Tx or MT3 to the Cx and Tx in comparison to no-treatment in the short-term for pain and disability.

CONCLUSION

This systematic review updates the evidence for MT combined or not with exercise and/or usual medical care for different stages of NP and provides recommendations for future studies. Two majors points could be highlighted, the first one is that combining different forms of MT with exercise is better than MT or exercise alone, and the second one is that mobilization need not be applied at the symptomatic level(s) for improvements of NP patients. These both points may have clinical implications for reducing the risk involved with some MT techniques applied to the cervical spine.

Spinal manipulation does not affect pressure pain thresholds in the absence of neuromodulators: a randomized controlled trial

BACKGROUND

Measurement of pressure pain threshold (PPT) is a way to determine one of the many potential treatment effects of spinal manipulative therapy.

OBJECTIVE

To determine how multiple spinal manipulations administered in a single-session affected PPTs at local and distal sites in asymptomatic individuals.

METHODS

Participants were randomly assigned into one of three groups: Group one (n = 18) received a lumbar manipulation followed by a cervical manipulation. Group two (n = 17) received a cervical manipulation followed by a lumbar manipulation. The control group (n = 19) received two bouts of five minutes of rest. At baseline and after each intervention or rest period, each participant's PPTs were obtained using a handheld algometer. The PPTs were tested bilaterally over the lateral epicondyles of the humerus and over the mid-bellies of the upper trapezius, lumbar paraspinal, and the tibialis anterior muscles. This study was registered with ClinicalTrials.gov, and its Identifier is NCT02828501.

RESULTS

Repeated-measures ANOVAs and Kruskal-Wallis tests showed no significant within- or between-group differences in PPT. Within-group effect sizes in the changes of PPT ranged from -.48 at the left paraspinal muscles to .24 at the left lateral humeral epicondyle. Statistical power to detect significant differences at α of 0.05 was calculated to be 0.94.

CONCLUSIONS

This study suggests that in young adults who do not have current or recent symptoms of spinal pain, multiple within-session treatments of cervical and lumbar spinal manipulation fail to influence PPTs. Changes in PPT that are observed in symptomatic individuals are likely to be primarily influenced by pain-related neuromodulators rather than by an isolated, mechanical effect of spinal manipulation.

Risks in teaching manipulation techniques in master programmes

High Velocity Techniques (HVT) in the (high) cervical spine are part of the standard curricula of manual therapy educational programmes. Little is known about the risk or the presence of adverse events during skills training sessions. This article describes two cases of students with both being at risk for an adverse event; one with a congenital artery aberration and one with cancer in the high cervical region. Teachers and educational programme developers should take risk management into account when teaching HVT.

Upper cervical and upper thoracic manipulation versus mobilization and exercise in patients with cervicogenic headache: a multi-center randomized clinical trial

Background

Although commonly utilized interventions, no studies have directly compared the effectiveness of cervical and thoracic manipulation to mobilization and exercise in individuals with cervicogenic headache (CH). The purpose of this study was to compare the effects of manipulation to mobilization and exercise in individuals with CH.

Methods

One hundred and ten participants (n = 110) with CH were randomized to receive both cervical and thoracic manipulation (n = 58) or mobilization and exercise (n = 52). The primary outcome was headache intensity as measured by the Numeric Pain Rating Scale (NPRS). Secondary outcomes included headache frequency, headache duration, disability as measured by the Neck Disability Index (NDI), medication intake, and the Global Rating of Change (GRC). The treatment period was 4 weeks with follow-up assessment at 1 week, 4 weeks, and 3 months after initial treatment session. The primary aim was examined with a 2-way mixed-model analysis of variance (ANOVA), with treatment group (manipulation versus mobilization and exercise) as the between subjects variable and time (baseline, 1 week, 4 weeks and 3 months) as the within subjects variable.

Results

The 2X4 ANOVA demonstrated that individuals with CH who received both cervical and thoracic manipulation experienced significantly greater reductions in headache intensity (p < 0.001) and disability (p < 0.001) than those who received mobilization and exercise at a 3-month follow-up. Individuals in the upper cervical and upper thoracic manipulation group also experienced less frequent headaches and shorter duration of headaches at each follow-up period (p < 0.001 for all). Additionally, patient perceived improvement was significantly greater at 1 and 4-week follow-up periods in favor of the manipulation group (p < 0.001).

Conclusions

Six to eight sessions of upper cervical and upper thoracic manipulation were shown to be more effective than mobilization and exercise in patients with CH, and the effects were maintained at 3 months.

Trial registration

NCT01580280 April 16, 2012.

Safety of thrust joint manipulation in the thoracic spine: a systematic review

BACKGROUND

There appears to be very little in the research literature on the safety of thrust joint manipulation (TJM) when applied to the thoracic spine.

PURPOSE

To retrospectively analyze all available documented case reports in the literature describing patients who had experienced severe adverse events (AE) after receiving TJM to their thoracic spine.

DATA SOURCES

Case reports published in peer reviewed journals were searched in Medline (using Ovid Technologies, Inc.), Science Direct, Web of Science, PEDro (Physiotherapy Evidence Database), Index of Chiropractic literature, AMED (Allied and Alternative Medicine Database), PubMed and the Cumulative Index to Nursing and Allied Health (CINHAL) from January 1950 to February 2015.

STUDY SELECTION

Case reports were included if they: (1) were peer-reviewed; (2) were published between 1950 and 2015; (3) provided case reports or case series; and (4) had TJM as an intervention. Articles were excluded if: (1) the AE occurred without TJM (e.g. spontaneous); (2) the article was a systematic or literature review; or (3) it was written in a language other than English or Spanish.

DATA EXTRACTION

Data extracted from each case report included: gender; age; who performed the TJM and why; presence of contraindications; the number of manipulation interventions performed; initial symptoms experienced after the TJM; as well as type of severe AE that resulted.

RESULTS

Ten cases, reported in 7 case reports, were reviewed. Cases involved females (8) more than males (2), with mean age being 43.5 years (SD=18.73, Range = 17 -71). The most frequent AE reported was injury (mechanical or vascular) to the spinal cord (7/10), with pneumothorax and hematothorax (2/10) and CSF leak secondary to dural sleeve injury (1/10).

LIMITATIONS

There were only a small number of case reports published in the literature and there may have been discrepancies between what was reported and what actually occurred, since physicians dealing with the effects of the AE, rather than the clinician performing the TJM, published the cases.

CONCLUSIONS

Serious AE do occur in the thoracic spine, most commonly, trauma to the spinal cord, followed by pneumothorax. This suggests that excessive peak forces may have been applied to thoracic spine, and it should serve as a cautionary note for clinicians to decrease these peak forces.

Safety of cervical spine manipulation: are adverse events preventable and are manipulations being performed appropriately? A review of 134 case reports

BACKGROUND

Cervical spine manipulation (CSM) is a commonly utilized intervention, but its use remains controversial.

PURPOSE

To retrospectively analyze all available documented case reports in the literature describing patients who had experienced severe adverse events (AEs) after receiving CSM to determine if the CSM was used appropriately, and if these types of AEs could have been prevented using sound clinical reasoning on the part of the clinician.

DATA SOURCES

PubMed and the Cumulative Index to Nursing and Allied Health were systematically searched for case reports between 1950 and 2010 of AEs following CSM.

STUDY SELECTION

Case reports were included if they were peer-reviewed; published between 1950 and 2010; case reports or case series; and had CSM as an intervention. Articles were excluded if the AE occurred without CSM (e.g. spontaneous); they were systematic or literature reviews. Data extracted from each case report included: gender; age; who performed the CSM and why; presence of contraindications; the number of manipulation interventions performed; initial symptoms experienced after the CSM; and type of resultant AE.

DATA SYNTHESIS

Based on the information gathered, CSMs were categorized as appropriate or inappropriate, and AEs were categorized as preventable, unpreventable, or unknown. Chi-square analysis with an alpha level of 0.05 was used to determine if there was a difference in proportion between six categories: appropriate/preventable, appropriate/unpreventable, appropriate/unknown, inappropriate/preventable, inappropriate/unpreventable, and inappropriate/unknown.

RESULTS

One hundred thirty four cases, reported in 93 case reports, were reviewed. There was no significant difference in proportions between appropriateness and preventability, P = .46. Of the 134 cases, 60 (44.8%) were categorized as preventable, 14 (10.4%) were unpreventable and 60 (44.8%) were categorized as 'unknown'. CSM was performed appropriately in 80.6% of cases. Death resulted in 5.2% (n = 7) of the cases, mostly caused by arterial dissection.

LIMITATIONS

There may have been discrepancies between what was reported in the cases and what actually occurred, since physicians dealing with the effects of the AE, rather than the clinician performing the CSM, published many of the cases.

CONCLUSIONS

This review showed that, if all contraindications and red flags were ruled out, there was potential for a clinician to prevent 44.8% of AEs associated with CSM. Additionally, 10.4% of the events were unpreventable, suggesting some inherent risk associated with CSM even after a thorough exam and proper clinical reasoning.

Bilateral and multiple cavitation sounds during upper cervical thrust manipulation

Background

The popping produced during high-velocity, low-amplitude (HVLA) thrust manipulation is a common sound; however to our knowledge, no study has previously investigated the location of cavitation sounds during manipulation of the upper cervical spine. The primary purpose was to determine which side of the spine cavitates during C1-2 rotatory HVLA thrust manipulation. Secondary aims were to calculate the average number of pops, the duration of upper cervical thrust manipulation, and the duration of a single cavitation.

Methods

Nineteen asymptomatic participants received two upper cervical thrust manipulations targeting the right and left C1-2 articulation, respectively. Skin mounted microphones were secured bilaterally over the transverse process of C1, and sound wave signals were recorded. Identification of the side, duration, and number of popping sounds were determined by simultaneous analysis of spectrograms with audio feedback using custom software developed in Matlab.

Results

Bilateral popping sounds were detected in 34 (91.9%) of 37 manipulations while unilateral popping sounds were detected in just 3 (8.1%) manipulations; that is, cavitation was significantly (P < 0.001) more likely to occur bilaterally than unilaterally. Of the 132 total cavitations, 72 occurred ipsilateral and 60 occurred contralateral to the targeted C1-2 articulation. In other words, cavitation was no more likely to occur on the ipsilateral than the contralateral side (P = 0.294). The mean number of pops per C1-2 rotatory HVLA thrust manipulation was 3.57 (95% CI: 3.19, 3.94) and the mean number of pops per subject following both right and left C1-2 thrust manipulations was 6.95 (95% CI: 6.11, 7.79). The mean duration of a single audible pop was 5.66 ms (95% CI: 5.36, 5.96) and the mean duration of a single manipulation was 96.95 ms (95% CI: 57.20, 136.71).

Conclusions

Cavitation was significantly more likely to occur bilaterally than unilaterally during upper cervical HVLA thrust manipulation. Most subjects produced 3–4 pops during a single rotatory HVLA thrust manipulation targeting the right or left C1-2 articulation; therefore, practitioners of spinal manipulative therapy should expect multiple popping sounds when performing upper cervical thrust manipulation to the atlanto-axial joint. Furthermore, the traditional manual therapy approach of targeting a single ipsilateral or contralateral facet joint in the upper cervical spine may not be realistic.

Immediate effects of a thoracic spine thrust manipulation on the autonomic nervous system: a randomized clinical trial

Thoracic spine manipulation has been shown to be effective for the management of neck pain. The purpose of this study was to investigate the immediate effect of a T3-T4 spinal thrust manipulation on autonomic nervous system activity in subjects with chronic cervical pain. An additional aim was to determine if the manipulation resulted in an immediate pain relief in patients with chronic neck pain when compared to a placebo intervention. One hundred subjects with chronic neck pain were randomly assigned to receive either a thoracic thrust manipulation or a placebo intervention. The Friedman's test was used to evaluate the change in pupil diameter within both groups. The Wilcoxen signed-ranks test was used to explore pupil changes over time and to make paired comparisons of the pupil change between the groups. The Mann-Whitney U test was used to compare the change in pain perception for the chronic cervical pain group subjects receiving either the thrust manipulation or the placebo intervention. The results demonstrated that manipulation did not result in a change in sympathetic activity. Additionally, there was no significant difference in the subject's pain perception (P = 0.961) when comparing the effects of the thrust manipulation to the placebo intervention within this group of subjects with chronic neck pain. The clinical impression of this study is that manipulation of the thoracic spine may not be effective in immediately reducing pain in patients with chronic neck pain.

Upper cervical and upper thoracic thrust manipulation versus nonthrust mobilization in patients with mechanical neck pain: a multicenter randomized clinical trial

STUDY DESIGN

Randomized clinical trial.

OBJECTIVE

To compare the short-term effects of upper cervical and upper thoracic high-velocity low-amplitude (HVLA) thrust manipulation to nonthrust mobilization in patients with neck pain.

BACKGROUND

Although upper cervical and upper thoracic HVLA thrust manipulation and nonthrust mobilization are common interventions for the management of neck pain, no studies have directly compared the effects of both upper cervical and upper thoracic HVLA thrust manipulation to nonthrust mobilization in patients with neck pain.

METHODS

Patients completed the Neck Disability Index, the numeric pain rating scale, the flexion-rotation test for measurement of C1-2 passive rotation range of motion, and the craniocervical flexion test for measurement of deep cervical flexor motor performance. Following the baseline evaluation, patients were randomized to receive either HVLA thrust manipulation or nonthrust mobilization to the upper cervical (C1-2) and upper thoracic (T1-2) spines. Patients were reexamined 48-hours after the initial examination and again completed the outcome measures. The effects of treatment on disability, pain, C1-2 passive rotation range of motion, and motor performance of the deep cervical flexors were examined with a 2-by-2 mixed-model analysis of variance (ANOVA).

RESULTS

One hundred seven patients satisfied the eligibility criteria, agreed to participate, and were randomized into the HVLA thrust manipulation (n = 56) and nonthrust mobilization (n = 51) groups. The 2-by-2 ANOVA demonstrated that patients with mechanical neck pain who received the combination of upper cervical and upper thoracic HVLA thrust manipulation experienced significantly (P<.001) greater reductions in disability (50.5%) and pain (58.5%) than those of the nonthrust mobilization group (12.8% and 12.6%, respectively) following treatment. In addition, the HVLA thrust manipulation group had significantly (P<.001) greater improvement in both passive C1-2 rotation range of motion and motor performance of the deep cervical flexor muscles as compared to the group that received nonthrust mobilization. The number needed to treat to avoid an unsuccessful outcome was 1.8 and 2.3 at 48-hour follow-up, using the global rating of change and Neck Disability Index cut scores, respectively.

CONCLUSION

The combination of upper cervical and upper thoracic HVLA thrust manipulation is appreciably more effective in the short term than nonthrust mobilization in patients with mechanical neck pain.

LEVEL OF EVIDENCE

Therapy, level 1b.

The effects of cervical high-velocity low-amplitude thrust manipulation on resting electromyographic activity of the biceps brachii muscle

There is a gap in the literature regarding the effects of spinal manipulation on extremity muscles that are unconnected to the vertebral column by an origin or insertion. This study investigated the effect of a right C5/6 high-velocity low-amplitude thrust (HVLAT) manipulation on resting electromyographic activity of the biceps brachii muscles bilaterally. A placebo-controlled, single-blind, repeated measures design employed an asymptomatic convenience sample (n=54) investigating three conditions: HVLAT, sham, and control. HVLAT demonstrated an excitatory effect with increased EMG activity of 94.20% (P=0.0001) and 80.05% (P=0.0001) for the right and left biceps respectively. A one-way repeated measures ANOVA revealed a significant difference (P=0.0001) in the mean percentage change of resting EMG activity, as did post hoc analyses (P=0.0001) between all three conditions. Subjects not experiencing cavitation post HVLAT demonstrated greater EMG increases for both right (P=0.0001) and left (P=0.014) biceps than those experiencing cavitation. The magnitude of mean EMG change for the right biceps was significantly greater than the left (P=0.011) post HVLAT. This study demonstrates a single HVLAT to the right C5/6 zygapophyseal joint elicits an immediate increase in resting EMG activity of the biceps bilaterally, irrespective of whether or not cavitation occurs.