Changes in pain sensitivity following spinal manipulation: a systematic review and meta-analysis

Supported biopsychosocial self-management for back-related leg pain: a randomized feasibility study integrating a whole person perspective

BACKGROUND

There is limited high-quality research examining conservative treatments for back-related leg pain (BRLP). This feasibility study was done in preparation for a full-scale trial comparing a whole-person supported self-management intervention to medical care for chronic BRLP.

METHODS

Participants were randomized to 12 weeks of individualized supported self-management delivered by physical therapists and chiropractors or medical care consisting of guideline-based pharmacologic care. Supported self-management was based on a behavioral model that used a whole person approach to enhance participants capabilities, opportunities, and motivations to engage in self-care. It combined BRLP education with psychosocial strategies (e.g., relaxed breathing, progressive muscle relaxation, guided imagery, communication skills) and physical modalities such as exercise and spinal manipulation therapy. Providers were trained to address participants' individualized needs and use behavior change and motivational communication techniques to develop a therapeutic alliance to facilitate self-management. Feasibility was assessed using pre-specified targets for recruitment and enrollment, intervention delivery, and data collection over the six-month study period. In addition, areas for potential refinement and optimization of processes and protocols for the full-scale trial were assessed.

RESULTS

We met or exceeded nearly all feasibility targets. Forty-two participants were enrolled over a six-month period in 2022 and very few individuals declined participation due to preferences for one treatment. All but one participant received treatment and 95% of participants attended the minimum number of visits (self-management = 6, medical care = 2). At 12 weeks, 95% of participants in the self-management group reported engaging in self-management practices learned in the program and 77% of medical care participants reported taking medications as prescribed. Satisfaction with the self-management intervention was high with 85% of participants reporting satisfaction with the program overall. Self-management intervention providers delivered all required activities at 72% of visits. Providers also noted some challenges navigating the shared decision-making process and deciding what self-management tools to prioritize. Over the six-month study period, completion rates were 91% for monthly surveys and 86% for weekly surveys.

CONCLUSION

We were able to demonstrate that a full-scale randomized trial comparing a whole-person supported self-management intervention to medical care for chronic BRLP is feasible and identified important areas for optimization.

Effect of adding thoracic manipulation for the management of patients with adhesive capsulitis: a randomized clinical trial

BACKGROUND

Research is supporting thoracic spine manipulation (TSM) as an intervention in treating adhesive capsulitis (AC) when coupled with physical therapy interventions.

PURPOSE

To investigate whether TSM improves AC outcomes when combined with physical therapy interventions.

METHOD

A double-blinded, randomized, controlled trial with 40 patients assigned into two groups. The experimental group (EG) received physical therapy intervention and TSM; the control group (CG) had physical therapy with sham manipulation. Both groups received interventions biweekly for 12 weeks. Outcomes included Visual Analogue Scale (VAS), Shoulder Pain and Disability Index (SPADI), scapular upward rotation, and shoulder passive range of motion conducted at baseline, after 1 session, 6 and 12 weeks.

RESULTS

Both groups improved significantly after 6 and 12 weeks in pain, disability (p = 0.01 for both; d = 1.53 and 1.46, respectively), scapular upward rotation, shoulder flexion (p = 0.02 for both; d = 2.2 and 0.92, respectively), abduction (p = 0.04; d = 0.07), and external rotation (p = 0.03; d = 0.7). However, CG showed no significant improvement in pain or disability after one session (p = 0.14 and p = 0.16, respectively; d = 0.46 for both). Between groups, results favored EG significantly in pain, disability, scapular upward rotation, shoulder flexion, and abduction (p = 0.02, p = 0.01, p = 0.02, p = 0.05, and p = 0.04, respectively) at 6 weeks (d = 0.81, d = 0.87, d = 0.67, d = 0.64, and d = 0.69, respectively).

CONCLUSION

The results suggest that adding TSM yielded superior clinical benefits when compared to physical therapy interventions in AC patients. Nevertheless, it is imperative to acknowledge a specific limitation in our study is the omission of passive internal rotation assessment. This aspect represents a notable constraint in our research.

CLINICAL TRIAL REGISTRY NUMBER

Pan African clinical trial registry "PACTR202303495421928".

Comparisons of the effects of psychologically-informed and usual physiotherapy on pain sensitivity in chronic low back pain: an exploratory randomized controlled trial

Introduction

The presence of altered central pain processing and modulation, as well as negative psychological factors, have been suggested to impede recovery in chronic low back pain (CLBP). Psychologically-informed physiotherapy (PiP) aims to specifically address the latter factors-in addition to physical factors-to improve treatment effects. This study aims to determine if the effect of PiP is superior to usual physiotherapy (UP) on pain sensitivity and modulation in participants with CLBP and if changes in these variables were associated with changes in clinical outcomes.

Methods

Forty participants with CLBP were randomly allocated to PiP or UP. Seven physiotherapy sessions over 6 weeks plus a booster session at an 11-week follow-up were delivered. Pressure pain threshold (PPT), temporal summation of pain (TSP), and exercise-induced hypoalgesia were assessed on lumbar, upper, and lower limb sites at baseline and after 6 weeks. Linear mixed models tested if PiP was superior to UP on pain sensitivity/modulation. Linear regressions tested if pain sensitivity/modulation changes were associated with changes in clinical outcomes (pain intensity, physical functioning, symptoms of central sensitization).

Results

PiP was not superior to UP to modulate pain sensitivity/modulation variables. All PPTs increased after 6 weeks regardless of the approach. Lumbar PPT and lumbar and lower limb TSP changes were associated with physical functioning changes.

Conclusion

Although our study suggests that neither approach has a superiority to impact on pain sensitivity, both approaches elicited widespread hypoalgesia. Future powered trials should verify if pain sensitivity can be a mediator of physical functioning improvement, as suggested by our results.

Self-Administered Traction as an Adjunct in the Chiropractic Treatment of Low Back Pain: A Case Report

Objective

The purpose of this case report is to describe self-administered lumbar traction as a component of the treatment of a patient with low back pain (LBP).

Clinical Features

A 41-year-old male chiropractic student presented with an exacerbation of intermittent LBP of approximately 2 years duration. Pain intensity was 4 to 8/10 on a verbal pain scale the day after exertion and 10 on the Patient Reported Outcomes Measurement Information System (PROMIS) 3a. Pain interference was 15 on the PROMIS-8a. The Oswestry Disability Index was 30%. Radiographs showed mild bilateral arthritic changes throughout the lumbar spine and sacroiliac joints. Diagnoses of acute exacerbation of recurrent, mechanical low back pain with thoracic and lumbar segmental dysfunction, lumbosacral spondylosis without myelopathy, and bilateral sacroiliac joint arthritis were made.

Intervention and Outcomes

The student received 14 treatments over 5 weeks consisting of spinal manipulation and therapeutic exercises in conjunction with clinician-supervised, self-administered traction. After 14 treatments, the patient was discharged, reporting resolution of LBP (pain intensity [PROMIS-3a] = 4; pain interference [PROMIS-8a] = 8; Oswestry 2%; and increased range of motion). Pain resolution remained for more than 2 years without additional treatment (pain intensity = 3; pain interference = 8; Oswestry 0%; continued increased range of motion).

Conclusion

The patient reported long-term benefit from a course of spinal manipulation and therapeutic exercises in conjunction with novel self-administered traction with flexion.

Spinal manipulation does not improve short-term pain and function in persons with painful shoulder: a systematic review with meta-analysis

PURPOSE

To investigate the benefit of spinal high-velocity low-amplitude thrust (HVLAT) in improving pain and disability in persons with painful shoulder as primary outcomes. Function, quality of life, persons (and clinicians) satisfaction, adverse events rate, and time for recovery were secondary outcomes.

METHODS

A systematic review with meta-analysis was conducted and MEDLINE, CENTRAL, Embase, and PEDro until 20 September 2023 were investigated. Two thousand eight hundred and ninety-nine records were retrieved and nine studies were included. Risk of bias of included studies was assessed through the Revised Cochrane risk-of-bias tool. The certainty of evidence of the pooled results was graded with GRADE approach.

RESULTS

The analysis included nine studies (441 persons). The pooled results showed non-significant differences between HVLAT versus sham in pain at pre-post follow-up (MD -0.13, 95% confidence interval (CI) -0.60; 0.35; p = 0.61, I2 = 0%), and at <4 days follow-up (SMD 0.16, 95%CI -0.16; 0.48; p = 0.34, I2 = 23%); in function at <4 days follow-up (SMD -0.29, 95%CI -0.69; 0.11; p = 0.16, I2 = 50%). The certainty of evidence ranged from low to very low.

CONCLUSIONS

HVLAT was not more effective than sham in improving pain and function at pre-post and at <4 days follow-up. When used as an "add-on technique", HVLAT did not improve pain nor disability.

The effect of foam rolling on local and distant pain sensitivity assessed with pressure pain thresholds in healthy participants and musculoskeletal pain patients: A systematic review

INTRODUCTION

The self-treatment with a foam roller is a popular form of myofascial release, although the underlying mechanisms, particularly on pain sensitivity, remain unclear. It is hypothesized that the hypoalgesic local effects are probably due to changes in fascial and muscle tissue, whereas remote effects may be influenced by central endogenous pain modulation. This systematic review aimed to quantify the difference between local and remote hypoalgesic effects of the foam rolling intervention.

METHOD

A systematic search was conducted in the databases Pubmed, Cochrane Library, Web of Science, and CINAHL. Published randomized controlled trials and non-randomized controlled trials investigating the effects of foam rolling on Pressure Pain Thresholds (PPTs) in healthy individuals and patients with musculoskeletal pain were included. Quality assessment and evidence synthesis were performed according to Cochrane Handbook recommendations. A meta-analysis was performed using standardized mean differences and 95% CIs.

RESULTS

Local PPTs changed after rolling in a pre-post comparison with a small effect size: SMD = -0.42 (95 % CI = -0.57 to -0.26); I2 = 1 %. Remote PPTs also changed after rolling in a pre-post comparison with a small effect size: SMD = -0.47 (95 % CI = -0.80 to -0.14); I2 = 0 %. Foam rolling showed no effect on local PPTs when compared with a control group: SMD = 0.10 (95 % CI = -0.19 to 0.39); I2 = 0 %.

CONCLUSION

No consistent effects of foam rolling on PPTs were demonstrated in healthy individuals.

Mechanisms of manipulation: a systematic review of the literature on immediate anatomical structural or positional changes in response to manually delivered high-velocity, low-amplitude spinal manipulation

BACKGROUND

Spinal manipulation (SM) has been claimed to change anatomy, either in structure or position, and that these changes may be the cause of clinical improvements. The aim of this systematic review was to evaluate and synthesise the peer-reviewed literature on the current evidence of anatomical changes in response to SM.

METHODS

The review was registered with PROSPERO (CRD42022304971) and reporting was guided by the standards of the PRISMA Statement. We searched Medline, Embase, CINAHL, AMED, Cochrane Library all databases, PEDro, and the Index to Chiropractic Literature from inception to 11 March 2022 and updated on 06 June 2023. Search terms included manipulation, adjustment, chiropractic, osteopathy, spine and spine-related structures. We included primary research studies that compared outcomes with and without SM regardless of study design. Manipulation was defined as high-velocity, low-amplitude thrust delivered by hand to the spine or directly related joints. Included studies objectively measured a potential change in an anatomical structure or in position. We developed a novel list of methodological quality items in addition to a short, customized list of risk of bias (RoB) items. We used quality and RoB items together to determine whether an article was credible or not credible. We sought differences in outcomes between SM and control groups for randomised controlled trials and crossover studies, and between pre- and post-SM outcomes for other study designs. We reported, in narrative form, whether there was a change or not.

RESULTS

The search retrieved 19,572 articles and 20 of those were included for review. Study topics included vertebral position (n = 3) facet joint space (n = 5), spinal stiffness (n = 3), resting muscle thickness (n = 6), intervertebral disc pressure (n = 1), myofascial hysteresis (n = 1), and further damage to already damaged arteries (n = 1). Eight articles were considered credible. The credible articles indicated that lumbar facet joint space increased and spinal stiffness decreased but that the resting muscle thickness did not change.

CONCLUSION

We found few studies on this topic. However, there are two promising areas for future study: facet joint space and spinal stiffness. A research strategy should be developed with funding for high quality research centres.

Exploring the immediate and short-term effect of lumbar spinal manipulation on pressure pain threshold: a randomized controlled trial of healthy participants

BACKGROUND

Lumbar spinal manipulative therapy (SMT) is a common intervention used to treat low back pain (LBP); however, the exact neurophysiological mechanisms of SMT reducing pain measured through pain pressure threshold (PPT) have not been fully explored beyond an immediate timeframe (e.g., immediately or five-minutes following) referencing a control group. Therefore, the purpose of this study was to investigate the neurophysiological effects of lumbar SMT compared to deactivated ultrasound using PPT immediately following and 30-minutes following SMT.

METHODS

A longitudinal, randomized controlled trial design was conducted between September to October 2023. Fifty-five participants were randomized into a control group of deactivated ultrasound (n = 29) or treatment group of right sidelying lumbar SMT (n = 26). PPT, recorded at the right posterior superior iliac spine (PSIS), was documented for each participant in each group prior to intervention, immediately, and 30-minutes after. A repeated measures ANOVA, with a post-hoc Bonferroni adjustment, was used to assess within-group and between-group differences in PPT. The significance level was set at a < 0.05 a priori.

RESULTS

Statistically significant differences were found between the deactivated ultrasound and lumbar SMT groups immediately (p = .05) and 30-minutes (p = .02) following intervention. A significant difference in the lumbar SMT group was identified from baseline to immediately following (p < .001) and 30-minutes following (p < .001), but no differences between immediately following and 30-minutes following intervention (p = .10). The deactivated ultrasound group demonstrated a difference between baseline and immediately after intervention with a reduced PPT (p = .003), but no significant difference was found from baseline to 30-minutes (p = .11) or immediately after intervention to 30-minutes (p = 1.0).

CONCLUSION

A right sidelying lumbar manipulation increased PPT at the right PSIS immediately after that lasted to 30-minutes when compared to a deactivated ultrasound control group. Future studies should further explore beyond the immediate and short-term neurophysiological effects of lumbar SMT to validate these findings.

TRIAL REGISTRATION

This study was retrospectively registered on 4 December 2023 in ClinicalTrials (database registration number NCT06156605).

Waste not, want not: call to action for spinal manipulative therapy researchers

BACKGROUND

Research waste is defined as research outcomes with no or minimal societal benefits. It is a widespread problem in the healthcare field. Four primary sources of research waste have been defined: (1) irrelevant or low priority research questions, (2) poor design or methodology, (3) lack of publication, and (4) biased or inadequate reporting. This commentary, which was developed by a multidisciplinary group of researchers with spinal manipulative therapy (SMT) research expertise, discusses waste in SMT research and provides suggestions to improve future research.

MAIN TEXT

This commentary examines common sources of waste in SMT research, focusing on design and methodological issues, by drawing on prior research and examples from clinical and mechanistic SMT studies. Clinical research is dominated by small studies and studies with a high risk of bias. This problem is compounded by systematic reviews that pool heterogenous data from varying populations, settings, and application of SMT. Research focusing on the mechanisms of SMT often fails to address the clinical relevance of mechanisms, relies on very short follow-up periods, and has inadequate control for contextual factors.

CONCLUSIONS

This call to action is directed to researchers in the field of SMT. It is critical that the SMT research community act to improve the way research is designed, conducted, and disseminated. We present specific key action points and resources, which should enhance the quality and usefulness of future SMT research.

An investigation of neurological and/or biomechanical factors underpinning the effect of a thrust manipulation on chronic ankle symptoms: an observational study

BACKGROUND

Ankle sprains are a commonly occurring musculoskeletal injury potentially resulting in persistent pain and/or altered motion. Thrust manipulation may serve as an interventional strategy but limited evidence exists on the mechanism(s) by which a change to symptoms might occur.

OBJECTIVE

The study sought to quantify the immediate effect of a thrust manipulation to the ankle to determine a mechanism by which change to symptoms occurred.

METHODS

Eleven participants (6 m/5f, 26.09 ± 4.25 yrs) with a history of ankle sprain that occurred greater than three months ago with recurring pain and/or altered motion were recruited. Participants underwent neurophysiological testing to assess any pain alterations and instrumented gait analysis (IGA) for biomechanical assessment pre-post thrust manipulation to the ankle.

RESULTS

There were no significant differences in ankle dorsiflexion (DF) (p = 0.62), plantarflexion (PF) (p = 0.23), ground reaction force (GRF), or velocity (p = 0.63) following thrust manipulation compared to baseline; however, pre- and post-data did show differences in pain pressure threshold (p = 0.046). There were no significant differences in dynamic pain measurements.

CONCLUSIONS

Ankle sprains that result in persistent pain and/or altered motion can be impacted by a thrust manipulation which appears to act through neurophysiological mechanisms.

Effects of exercise combined with cervicothoracic spine self-mobilization on chronic non-specific neck pain

To investigate the short-term effects and differences between exercise alone and exercise combined with self-mobilization training on chronic non-specific neck pain (CNSNP). Thirty subjects who met the criteria were recruited and randomly assigned to the exercise training group, the exercise combined with cervical self-mobilization training group (ECCM), and the exercise combined with cervicothoracic self-mobilization training group (ECCTM). The exercise training group received 6 weeks of deep neck flexor under biofeedback and scapular stability training, and the other two groups received 6 weeks of cervical self-mobilization and cervicothoracic self-mobilization, respectively, in addition to exercise training. Neck pain, cervical range of motion (ROM), neck disability, strength and endurance of deep neck flexor and quality of life were assessed before and after 6 weeks of training. The study results showed that all the three training programs for 6 weeks increased the strength and endurance of deep neck flexor, increased cervical ROM, reduced pain, and improved neck function (P < 0.05). The exercise combined with self-mobilization two groups compared with only the exercise training group had better improvement in ROM of extension, lateral flexion, rotation and quality of life (P < 0.05). Compared with exercise alone and exercise combined with cervical self-mobilization training, the exercise combined with cervicothoracic self-mobilization training was the best in improving ROM of right lateral flexion (exercise training group vs ECCTM: P < 0.01, d = 1.61, ECCM vs ECCTM: P < 0.05, d = 1.14) and pain (exercise training group vs ECCTM: P < 0.05, d = 1.34, ECCM vs ECCTM: P < 0.05, d = 1.23). Deep flexor muscle and shoulder stability training can improve the endurance and strength of the deep flexor muscles of the neck and coordinate the movement patterns of the shoulder and neck. Self-mobilization techniques can promote improvements in cervical lateral flexion and rotation range of motion, alleviate neck disability and further improve quality of life. A combination of exercise and cervicothoracic self-mobilization training appears beneficial for the management of neck pain.

Rehabilitation of the painful elbow

Although lateral elbow pain and medial ulnar collateral ligament injury are common musculoskeletal pathologies in overhead athletes, the evidence supporting specific interventions for managing these conditions is scarce. Management of these conditions has been guided mostly by expert opinion rather than empirical evidence, yet the lack of comparative data in the literature has not negatively affected return-to-play rates following surgery. However, an understanding of what is known regarding unimodal and multimodal treatments for lateral elbow pain and medial ulnar collateral ligament injury is needed for clinicians to select evidence-based treatment pathways and highlight what is not known to develop future high-quality investigations.

An overview of systematic reviews examining the quantitative sensory testing-derived hypoalgesic effects of manual therapy for musculoskeletal pain

BACKGROUND

Changes in quantitative sensory testing (QST) after manual therapy can provide insight into pain relief mechanisms. Prior systematic reviews have evaluated manual-therapy-induced QST change. This overview of systematic reviews aims to consolidate this body of literature and critically review evidence on the hypoalgesic effects of manual therapy in clinical populations.

METHODS

A comprehensive search was conducted on PubMed, CINAHL, PsycInfo, and Embase. Peer-reviewed systematic reviews with or without meta-analysis were eligible if the reviews examined the effect of manual therapy compared to non-manual therapy interventions on QST outcomes in clinical populations. Methodological quality was assessed with the AMSTAR 2 tool. Meta-analysis results and qualitative (non-meta-analysis) interpretations were summarized by type of manual therapy. Overlap of studies was examined with the corrected covered area (CCA) index.

RESULTS

Thirty systematic reviews, including 11 meta-analyses, met inclusion. There was a slight overlap in studies (CCA of 1.72% for all reviews and 1.69% for meta-analyses). Methodological quality was predominantly low to critically low. Eight (27%) reviews examined studies with a range of manual therapy types, 13 (43%) reviews focused on joint-biased manual therapy, 7 (23%) reviews focused on muscle-biased manual therapy, and 2 (7%) reviews focused on nerve-biased manual therapy. Twenty-nine (97%) reviews reported on pressure pain threshold (PPT). Meta-analytic results demonstrated conflicting evidence that manual therapy results in greater hypoalgesic effects compared to other interventions or controls.

CONCLUSION

Our overview of QST effects, which has relevance to mechanisms underlying hypoalgesia, shows conflicting evidence from mostly low to critically low systematic reviews.

Does manual therapy meaningfully change quantitative sensory testing and patient reported outcome measures in patients with musculoskeletal impairments related to the spine?: A 'trustworthy' systematic review and meta-analysis

OBJECTIVES

To perform a 'trustworthy' systematic review (SR) with meta-analysis on the potential mechanisms of manual therapy used to treat spinal impairments.

DESIGN

SR with meta-analysis.

LITERATURE SEARCH

Articles published between January 2010 and October 2022 from CENTRAL, CINAHL, MEDLINE, PubMed, ProQuest, and PEDro.

METHODS

This SR included English-language randomized clinical trials (RCTs) involving manual therapy to treat spinal impairments in adults. The primary outcome was pressure pain thresholds (PPTs). To synthesize RCTs with high confidence in estimated effects using the GRADE, RCTs with questionable prospective, external, and internal validity, and high risk of bias (RoB) were excluded.

RESULTS

Following title and abstract screening, 89 full-text RCTs were reviewed. Twenty-two studies included the criteria of interest. Sixteen were not prospectively registered, two contained discussion/conclusions judged to be inconsistent with the registry, and one was rated as having a high RoB. Three studies met the inclusion criteria; heterogeneous interventions and locations for PPT testing prevented synthesis into practice recommendations. The two studies with high confidence in estimated effects had small effect sizes, and one study had confidence intervals that crossed zero for the outcome measures of interest.

DISCUSSION

Standardized PPT testing, as a potential measure of centrally mediated pain, could provide clues regarding the mechanisms of manual therapy or help identify/refine research questions.

CONCLUSION

High-quality RCTs could not be synthesized into strong conclusions secondary to the dissimilarity in research designs. Future research regarding quantitative sensory testing should develop RCTs with high confidence in estimated effects that can be translated into strong recommendations.

Changes in biochemical markers following a spinal manipulation - a systematic review update

OBJECTIVE

The aim of this systematic review was to update the current level of evidence for spinal manipulation in influencing various biochemical markers in healthy and/or symptomatic population.

METHODS

This is a systematic review update. Various databases were searched (inception till May 2023) and fifteen trials (737 participants) that met the inclusion criteria were included in the review. Two authors independently screened, extracted and assessed the risk of bias in included studies. Outcome measure data were synthesized using standard mean differences and meta-analysis for the primary outcome (biochemical markers). The Grading of Recommendations, Assessment, Development and Evaluation (GRADE) was used for assessing the quality of the body of evidence for each outcome of interest.

RESULTS

There was low-quality evidence that spinal manipulation influenced various biochemical markers (not pooled). There was low-quality evidence of significant difference that spinal manipulation is better (SMD -0.42, 95% CI - 0.74 to -0.1) than control in eliciting changes in cortisol levels immediately after intervention. Low-quality evidence further indicated (not pooled) that spinal manipulation can influence inflammatory markers such as interleukins levels post-intervention. There was also very low-quality evidence that spinal manipulation does not influence substance-P, neurotensin, oxytocin, orexin-A, testosterone and epinephrine/nor-epinephrine.

CONCLUSION

Spinal manipulation may influence inflammatory and cortisol post-intervention. However, the wider prediction intervals in most outcome measures point to the need for future research to clarify and establish the clinical relevance of these changes.

Cervical musculoskeletal impairments and pain sensitivity in migraine patients

INTRODUCTION

Currently, examination of migraine patients relies on a clinical interview investigating symptoms characteristics. Despite this, to help identify distinct migraine subtypes and allow a personalized treatment approach, biomarkers to profile distinct migraine subtypes should be utilized in clinical and research settings. Therefore, there is a need to include physical and psychophysical examinations aimed at assessing migraine features quantitatively.

PURPOSE

This paper aimed to discuss if increased pressure pain sensitivity and impaired cervical musculoskeletal function could be considered 1) as quantitative features of migraine and 2) if they could be used as biomarkers to profile migraine patients in distinct subtypes.

IMPLICATION

Increased pain sensitivity and cervical musculoskeletal impairments have been suggested as quantitative biomarkers to phenotype and subgroup migraine patients in clinical and research settings. This could provide the first step for a mechanistically-driven and personalized treatment approach according to migraine phenotypes.

Changes in pulmonary function following thoracic spine manipulation in a healthy inactive older adult population-a pilot study

[Purpose] Pulmonary function pathology is primarily treated pharmacologically, with a range of medication side effects. Few studies have systematically examined non-pharmacologic approaches such as joint manipulation effects on pulmonary function. This study examined the immediate and short-term effects of thoracic manipulation on pulmonary function. [Participants and Methods] Twenty-one physically inactive otherwise healthy participants aged 50 years or older were randomly assigned to either receive three sessions of thoracic manipulation (n=10) or three sessions of "sham intercostal training" (n=11). Outcome measures included forced vital capacity, maximal voluntary ventilation and thoracic excursion during maximal inhalation and exhalation. [Results] There was a statistically significant difference in maximal voluntary ventilation in the manipulation group, when measured within a week of the third intervention session and immediate effects in thoracic excursion during exhalation in the sham group following a single intervention session. There were no significant changes in other measures. [Conclusion] Spinal manipulation had no immediate effect on pulmonary function, however, affected an improvement in maximal voluntary ventilation within 7 days following a third session. The sham intervention showed a change in thoracic excursion during exhalation after the first session. Future research is necessary to further explore the relationship between thoracic manipulation and pulmonary function.

Regional Sensorimotor Effects of Chiropractic Spinal Manipulation: Preliminary Results From an Experimental Study

OBJECTIVE

The purpose of this study was to assess the effects of different spinal manipulation (SM) techniques and target segments on a specific dermatome and myotome, when compared with a remote spinal cord segment that served as a control location.

METHODS

Twenty-nine healthy volunteers were randomized to receive instrumental (Activator IV, Activator Methods International Ltd) or manual SM at the C6, C1, and T4 vertebral segments in 3 independent sessions. Pressure pain thresholds (PPTs) and muscle strength were examined at the C6 (test) and L4 (control) dermatomes and myotomes, at baseline and after intervention. Linear mixed-effects models were used to analyze changes over time and interindividual variability.

RESULTS

Pressure pain thresholds significantly increased at both proximal and distal C6 dermatome locations (P < .05), irrespective of the technique and segment of application (P > .2). No significant changes were observed at the L4 dermatome. Muscle strength remained unchanged throughout the study. Multilevel modeling revealed significant associations between increased PPTs along the C6 dermatome (P < .001), whereas the combination of technique and target segment predicted PPT increases at the proximal C6 dermatome.

CONCLUSION

These findings support regional, rather than segmental mechanisms underlying the sensory effects of SM. Specifically, significant increases in PPTs along the C6 dermatome suggest localized effects on pain sensitivity, which may depend on the target spinal region. Further investigation is needed to better understand these regional changes of SM and their potential clinical implications.

Effectiveness of a Manual Therapy Protocol in Women with Pelvic Pain Due to Endometriosis: A Randomized Clinical Trial

A randomized controlled trial was carried out to assess the effectiveness of a manual therapy protocol in terms of the clinical characteristics, quality of life, and emotional condition of the women with endometriosis-related pelvic pain. Forty-one women (mean age of 36.10 (6.97) years) with pelvic pain due to endometriosis were randomly divided into (i) a manual therapy group (MTG) (n = 21) and (ii) a placebo group (PG) (n = 20). Both groups received an 8-week intervention. Pain, lumbar mobility, endometriosis health profile, quality of life, depression and anxiety levels, and the patient's perception of change were assessed before (T0) and after (T1) the intervention, as well as at a one-month follow-up (T2) and a six-month follow-up (T3). The MTG significantly improved pain intensity, powerlessness, lumbar mobility, and physical quality of life at T1 (p < 0.05). The results were maintained for pain intensity at T2 and T3. In addition, both the MTG and PG improved emotional wellbeing at T1 (p < 0.05). Neither group improved in terms of social support, self-image, and depression and anxiety levels after the intervention (p > 0.05). In conclusion, manual therapy may be an excellent complement to the gynecological treatment of endometriosis-related pelvic pain by alleviating pain and improving women's endometriosis health profile and physical quality of life.

Expectations affect pain sensitivity changes during massage

BACKGROUND

Pain-inducing massage produces comparable changes in pain sensitivity as a cold pressor task, suggesting shared neurophysiological mechanisms of conditioned pain modulation. Manual therapy and conditioned pain modulation are influenced by positive and negative expectations. Therefore, the purpose of this study was to examine the effects of positive and negative expectations on pain-free and pain-inducing massage.

METHODS

56 healthy participants were randomly assigned to receive a positive or negative expectation instructional set followed by a pain-inducing or a pain-free massage. Pressure pain threshold (PPT) was measured followed by each interval of massage. A repeated measures ANCOVA controlling for post-randomization differences in sex tested for massage x expectation set x PPT interaction effects, as well as two-way interaction effects.

RESULTS

A significant three-way interaction effect (p = 0.04) and time x expectation interaction effect was observed for individuals receiving pain inducing massage (p = 0.02). Individuals who received the positive expectation instructional set demonstrated significantly higher PPT at minutes 3 and 4 of massage compared to individuals who received the negative expectation instructional set.

CONCLUSIONS

Expectations impact pain sensitivity changes produced during massage. Clinicians planning to provide pain-inducing massage should consider the role of expectations in modulating pain sensitivity changes.

Criterion-Related Validation of a Music-Based Attention Assessment for Individuals with Traumatic Brain Injury

The music-based attention assessment (MAA) is a melody contour identification task that evaluates different types of attention. Previous studies have examined the psychometric and physiological validity of the MAA across various age groups in clinical and typical populations. The purpose of this study was to confirm the MAA's criterion validity in individuals with traumatic brain injury (TBI) and to correlate this with standardized neuropsychological measurements. The MAA and various neurocognitive tests (i.e., the Wechsler adult intelligence scale DST, Delis-Kaplan executive functioning scale color-word interference test, and Conner's continuous performance test) were administered to 38 patients within two weeks prior to or post to the MAA administration. Significant correlations between MAA and neurocognitive batteries were found, indicating the potential of MAA as a valid measure of different types of attention deficits. An additional multiple regression analysis revealed that MAA was a significant factor in predicting attention ability.

The short-term effects of instrument-based mobilization compared with manual mobilization for low back pain: A randomized clinical trial

BACKGROUND

Despite being used as a manipulation technique, no studies have examined the effectiveness of physiotherapy instrument mobilization (PIM) as a mobilization technique on pain and functional status in patients with low back pain (LBP).

OBJECTIVE

To investigate the effectiveness of PIM in patients with LBP and to compare it with the effectiveness of manual mobilization.

METHODS

This is a double blind, randomized clinical trial. Thirty-two participants with LBP were randomly assigned to one of two groups. The PIM group received lumbar mobilization using an activator instrument, stabilization exercises, and education; and the manual group received lumbar mobilization using a pisiform grip, stabilization exercises, and education. Both groups had a total of 4 treatment sessions over 2-3 weeks. The following outcomes were measured before the intervention, and after the first and fourth sessions: Numeric Pain Rating Scale (NPRS), Oswestry Disability Index (ODI) scale, Pressure pain threshold (PPT), lumbar spine range of motion (ROM), and lumbar multifidus muscle activation.

RESULTS

There were no differences between the PIM group and the manual group in any outcome measures. However, over the period of study, there were improvements in both groups in NPRS (PIM: 3.23, Manual: 3.64 points), ODI (PIM: 17.34%, Manual: 14.23%), PPT (PIM: ⩽ 1.25, Manual: ⩽ 0.85 kg.cm2), lumbar spine ROM (PIM: ⩽ 9.49∘, Manual: ⩽ 0.88∘), and/or lumbar multifidus muscle activation (percentage thickness change: PIM: ⩽ 4.71, Manual: ⩽ 4.74 cm; activation ratio: PIM: ⩽ 1.17, Manual: ⩽ 1.15 cm).

CONCLUSIONS

Both methods of lumbar spine mobilization demonstrated comparable improvements in pain and disability in patients with LBP, with neither method exhibiting superiority over the other.

Electromyographic Responses of Neck, Back, and Limb Outlet Muscles Associated With High-Velocity, Low-Amplitude Manual Cervical and Upper Thoracic Spinal Manipulation of Individuals With Mild Neck Disability: A Descriptive Observational Investigation

OBJECTIVES

The purpose of this study was to investigate the extent of electromyographic responses associated with manual high-velocity, low-amplitude (HVLA) spinal manipulation systematically applied to the upper and lower cervical and upper thoracic spines in a cohort with mild neck disability.

METHODS

The study was a descriptive observational investigation, with all participants receiving the same interventions. Nineteen participants with mild neck disability received 6 manual HVLA manipulations to the cervical and upper thoracic spine. Bipolar surface electromyography electrode pairs were used to measure responses of 16 neck, back, and limb outlet muscles bilaterally. The number of electromyographic responses was then calculated.

RESULTS

Electromyographic responses associated with cervical and thoracic manipulation occurred in a median of 4 of the 16 (range: 1-14) recorded muscles. Cervical spinal manipulation was associated with the highest rates of electromyographic responses in neck muscles, whereas responses in back muscles were highest after upper thoracic manipulation.

CONCLUSION

Cervical spinal manipulation was associated with the highest rate of electromyographic responses in muscles of the cervical spine (sternocleidomastoid and splenius cervicis), whereas responses in back muscles (upper and middle trapezius, latissimus dorsi, and longissimus thoracis) were highest after upper thoracic manipulations. This result suggests that electromyographic muscular responses associated with spinal manipulation primarily occur locally (close to the target segment) rather than distally.

The Immediate Effect of Adding Lumbar Mobilization to A Static Stretching Program on Hamstrings Range of Motion: An Exploratory Study

A contributing risk factor and a byproduct of a hamstrings strain is limited hamstrings range of motion (ROM). Some evidence supports static stretching (SS) and lumbar spinal mobilization therapy (LSMT) as an effective means for increasing hamstrings ROM. However, the efficacy of combining LSMT and SS for increasing hamstrings ROM is unknown. The objective of the study is to quantify the immediate effects of the combination of LSMT and SS compared to LSMT and SS on hamstrings ROM in a healthy population. Thirty participants were randomized by block allocation into one of three intervention groups: (1) LSMT (unilateral lumbar PA mobilization at L-4); (2) SS; or (3) combination of LSMT and SS. Hamstrings ROM was measured pre- and post-intervention by the active knee extension test (AKET). There was no group-by-time interaction effect (p = 0.871). Within group analysis revealed a significant statistical change and a large effect size: LSMT (p = .037, RCI = 3.36, d = 0.771); SS (p = 0.035, RCI = 2.94, d = 0.781); combination (p = .005, RCI = 4.21, d = 1.186. The findings suggest that the combination of LSMT and SS does not have a further effect on hamstrings ROM compared to the individual results of LSMT or SS.

Pressure pain thresholds in a real-world chiropractic setting: topography, changes after treatment, and clinical relevance?

BACKGROUND

Changes in pain sensitivity are a commonly suggested mechanism for the clinical effect of spinal manipulative therapy (SMT). Most research has examined pressure pain thresholds (PPT) and has primarily been conducted in controlled experimental setups and on asymptomatic populations. Many important factors are likely to differ between research and clinical settings, which may affect PPT changes following SMT. Therefore, we planned to investigate PPT before and after clinical chiropractic care and investigate relationships with various potentially clinically-relevant factors.

METHODS

We recruited participants from four Danish chiropractic clinics between May and August 2021. A total of 129 participants (72% of the invited) were included. We measured PPT at eight pre-determined test sites (six spinal and two extra-spinal) immediately before (pre-session) and immediately after (post-session) the chiropractic consultation. We used regression analyses to investigate PPT changes, including the following factors: (i) vertebral distance to the nearest SMT site, (ii) rapid clinical response, (iii) baseline PPT, (iv) number of SMTs performed, (v) at the region of clinical pain compared to other regions, and (vi) if other non-SMT treatment was provided. We also performed topographic mapping of pre-session PPTs.

RESULTS

After the consultation, there was a non-significant mean increase in PPT of 0.14 kg (95% CIs = - 0.01 to 0.29 kg). No significant associations were found with the distance between the PPT test site and nearest SMT site, the clinical response of participants to treatment, the pre-session PPT, the total number of SMTs performed, or the region/s of clinical pain. A small increase was observed if myofascial treatment was also provided. Topographic mapping found greater pre-session PPTs in a caudal direction, not affected by the region/s of clinical pain.

CONCLUSIONS

This study of real-world chiropractic patients failed to demonstrate a substantial local or generalized increase in PPT following a clinical encounter that included SMT. This runs counter to prior laboratory research and questions the generalizability of highly experimental setups investigating the effect of SMT on PPT to clinical practice.

Effectiveness of cervicothoracic and thoracic manual physical therapy in managing upper quarter disorders - a systematic review

STUDY DESIGN

Systematic review.

BACKGROUND

Physical therapists often use cervicothoracic and thoracic manual techniques to treat musculoskeletal disorders of the upper quarter ,however, the overall effectiveness of this approach remains to be elucidated.

OBJECTIVE

This systematic review explored studies that examined the short- and long-term effectiveness of manual physical therapy directed at the cervicothoracic and thoracic region in the management of upper quarter musculoskeletal conditions.

METHODS

The electronic databases MEDLINE, AMED, CINAHL, and Embase were searched from their inception through 30 October 2020. Eligible clinical trials included those where human subjects treated with cervicothoracic and/or thoracic manual procedures were compared with a control group or other interventions. The methodological quality of individual studies was assessed using the PEDro scale.

RESULTS

The initial search returned 950 individual articles. After the screening of titles and abstracts, full texts were reviewed by two authors, with 14 articles determined to be eligible for inclusion. PEDro scores ranged from 66 to 10 (out of a maximum score of 10). In the immediate to 52-week follow-up period, studies provided limited evidence that cervicothoracic and thoracic manual physical therapy may reduce pain and improve function when compared to control/sham or other treatments.

CONCLUSIONS

Evidence provides some support for the short-termeffectiveness of cervicothoracic and thoracic manual physical therapy in reducing pain and improving function in people experiencing upper quarter musculoskeletal disorders. Evidence is lacking for long-term effectiveness as only two studies explored outcomes beyond 26 weeks and this was for patient-perceived improvement.

PROSPERO ID

CRD42020219456.

A clinical crossover trial of the effect of manipulative therapy on pain and passive and active range of motion of the painful hip

OBJECTIVES

This study aims to determine whether manipulative therapy of the hip joint can increase range of motion (ROM) and/or decrease pain in individuals experiencing symptomatic hip pain.

METHODS

Non-disabled young adults were recruited on campus of a chiropractic college for this randomized crossover study. Subjects' hip active and passive ROM and pain perception were measured. Subjects then received a drop-piece hip manipulation (DPHM) or an alternative treatment, followed by measurement of active and passive ROM and pain.

RESULTS

Eight males and 12 females (n=20) between the ages of 21-32 years completed the study. Statistically significant improvements in numeric pain scale (NRS) and passive abduction were observed for the manipulation group when compared to the alternative treatment. No significant change was observed for all other hip ranges.

CONCLUSIONS

DPHM of the symptomatic hip joint in a small sample of young adults resulted in statistically significant improvements in pain and passive abduction when compared to sham manipulation. Due to low sample size, further research is recommended.

Evidence for increased neuromuscular drive following spinal manipulation in individuals with subacromial pain syndrome

BACKGROUND

Thoracic spinal manipulation can improve pain and function in individuals with shoulder pain; however, the mechanisms underlying these benefits remain unclear. Here, we evaluated the effects of thoracic spinal manipulation on muscle activity, as alteration in muscle activity is a key impairment for those with shoulder pain. We also evaluated the relationship between changes in muscle activity and clinical outcomes, to characterize the meaningful context of a change in neuromuscular drive.

METHODS

Participants with shoulder pain related to subacromial pain syndrome (n = 28) received thoracic manipulation of low amplitude high velocity thrusts to the lower, middle and upper thoracic spine. Electromyographic muscle activity (trapezius-upper, middle, lower; serratus anterior; deltoid; infraspinatus) and shoulder pain (11-point scale) was collected pre and post-manipulation during arm elevation, and normalized to a reference contraction. Clinical benefits were assessed using the Pennsylvania Shoulder Score (Penn) at baseline and 2-3 days post-intervention.

FINDINGS

A significant increase in muscle activity was observed during arm ascent (p = 0.002). Using backward stepwise regression analysis, a specific increase in the serratus anterior muscle activity during arm elevation explained improved Penn scores following post-manipulation (p < 0.05).

INTERPRETATION

Thoracic spinal manipulation immediately increases neuromuscular drive. In addition, increased serratus anterior muscle activity, a key muscle for scapular motion, is associated with short-term improvements in shoulder clinical outcomes.

Hypoalgesic effects of specific vs non-specific cervical manipulation in healthy subjects: a randomized crossover trial

BACKGROUND

Joint manipulation is generally used to reduce musculoskeletal pain; however, evidence has emerged challenging the effects associated with the specificity of the manipulated vertebral segment. The aim of this study was to verify immediate hypoalgesic effects between specific and non-specific cervical manipulations in healthy subjects.

METHOD

Twenty-one healthy subjects (18-30 years old; 11 males, 10 females) were selected to receive specific cervical manipulation at the C6-7 segment (SCM) and non-specific cervical manipulation (NSCM) in aleatory order. A 48h interval between manipulations was considered. Pressure pain threshold (PPT) was measured pre- and post-manipulation with a digital algometer on the dominant forearm.

RESULTS

The SCM produced a significant increase in the PPT (P < 0.001) however no difference was observed in the PPT after the NCSM (P = 0.476). The difference between the two manipulation techniques was 37.26 kPa (95% CI: 14.69 to 59.83, p = 0.002) in favor of the SCM group CONCLUSION: Specific cervical manipulation at the C6-7 segment appears to increase PPT on the forearm compared to non-specific cervical manipulation in healthy subjects.

Segmental Chiropractic Spinal Manipulation Does not Reduce Pain Amplification and the Associated Pain-Related Brain Activity in a Capsaicin-Heat Pain Model

Musculoskeletal injuries lead to sensitization of nociceptors and primary hyperalgesia (hypersensitivity to painful stimuli). This occurs with back injuries, which are associated with acute pain and increased pain sensitivity at the site of injury. In some cases, back pain persists and leads to central sensitization and chronic pain. Thus, reducing primary hyperalgesia to prevent central sensitization may limit the transition from acute to chronic back pain. It has been shown that spinal manipulation (SM) reduces experimental and clinical pain, but the effect of SM on primary hyperalgesia and hypersensitivity to painful stimuli remains unclear. The goal of the present study was to investigate the effect of SM on pain hypersensitivity using a capsaicin-heat pain model. Laser stimulation was used to evoke heat pain and the associated brain activity, which were measured to assess their modulation by SM. Eighty healthy participants were recruited and randomly assigned to one of the four experimental groups: inert cream and no intervention; capsaicin cream and no intervention; capsaicin cream and SM at T7; capsaicin cream and placebo. Inert or capsaicin cream (1%) was applied to the T9 area. SM or placebo were performed 25 min after cream application. A series of laser stimuli were delivered on the area of cream application (1) before cream application, (2) after cream application but before SM or placebo, and (3) after SM or placebo. Capsaicin cream induced a significant increase in laser pain (p < 0.001) and laser-evoked potential amplitude (p < 0.001). However, SM did not decrease the amplification of laser pain or laser-evoked potentials by capsaicin. These results indicate that segmental SM does not reduce pain hypersensitivity and the associated pain-related brain activity in a capsaicin-heat pain model.

Low Back Pain: A Comprehensive Review on the Diagnosis, Treatment Options, and the Role of Other Contributing Factors

BACKGROUND: In recent years, low back pain (LBP) is a growing major health issue around the world and mostly addressed in primary healthcare settings. This may be due to changing work environment including the nature of long sitting work hours, especially in the booming information and technology (IT) and Business Process Outsourcing (BPO) industry. LBP is normally considered as a combination of various types of pain and its related conditions, which eventually lead to disabilities. AIM: In this article, the aim is to discuss the current and future perspectives of LBP mainly on diagnosis and therapeutic front of LBP. METHODS: A search was performed using electronic databases, which include PubMed Central and Google Scholar, using the related key words “back pain and low back pain.” All related peer reviewed published articles were included regardless of the language, region, or the publication date. RESULTS: Although the management of LBP both in terms of diagnosis as well as in the therapeutic options has witnessed considerable progress but challenges are still exist not only within countries but also in the regions and continents among various medical professionals. However, in the past few years, a huge array of coordinated but randomized multi-center clinical studies were performed and various detailed insight investigations have been done, and substantial clinical guidelines have become available. Hence, a new view on evidence-based management approach for LBP has significantly improved recently and discussed here. CONCLUSION: Based on the available evidence and literature, this comprehensive review discusses the present and future perspectives of LBP mainly on diagnosis and therapeutic front for LBP. In addition, current intervention and prevention plans have failed to lessen the considerable burden of LBP and hence several areas which require more details, which deserves additional discussion to augment us through an understanding of this very important topic on improvements of multi tasked outcomes to benefit the affected patients.

Myofascial Release for Chronic Low Back Pain: A Systematic Review and Meta-Analysis

Background: Chronic low back pain (CLBP) is one of the most common musculoskeletal diseases in the elderly, which has a severe impact on the health of the elderly. However, CLBP treatment is very challenging, and more effective treatment methods are needed. Myofascial release may be an effective therapy for the management of chronic musculoskeletal pain. It is widely used clinically to treat CLBP, but its clinical efficacy is still controversial. Objective: This study aims to systematically evaluate the effectiveness of myofascial release for patients with CLBP. Methods: We selected PubMed, Cochrane Library, EMBASE database, and Web of Science database articles published until April 5, 2021. Randomized controlled trials (RCTs) of myofascial release for CLBP were included. Outcome measures included pain, physical function, quality of life, balance function, pain pressure-threshold, trunk mobility, and mental health. For each outcome, Standardized mean differences (SMD) or mean differences (MD) and 95% confidence intervals (CIs) were calculated. Results: Eight RCTs (n = 375) were included based on inclusion and exclusion criteria. The meta-analysis showed that the overall efficacy of myofascial release for CLBP was significant, including two aspects: pain [SMD = -0.37, 95% CI (-0.67, -0.08), I 2 = 46%, P = 0.01] and physical function [SMD = -0.43, 95% CI (-0.75, -0.12), I 2 = 44%, P = 0.007]. However, myofascial release did not significantly improve quality of life [SMD = 0.13, 95% CI (-0.38, 0.64), I 2 = 53%, P = 0.62], balance function [SMD = 0.58, 95% CI (-0.49, 1.64), I 2 = 82%, P = 0.29], pain pressure-threshold [SMD = 0.03,95% CI (-0.75, 0.69), I 2 = 73%, P = 0.93], trunk mobility [SMD = 1.02, 95% CI (-0.09, 2.13), I 2 = 92%, P = 0.07] and mental health [SMD = -0.06, 95% CI (-0.83, 0.71), I 2 = 73%, P = 0.88]. Conclusions: In this study, we systematically reviewed and quantified the efficacy of myofascial release in treating CLBP. The meta-analysis results showed that myofascial release significantly improved pain and physical function in patients with CLBP but had no significant effects on balance function, pain pressure-threshold, trunk mobility, mental health, and quality of life. However, due to the low quality and a small number of included literature, more and more rigorously designed RCTs should be included in the future to verify these conclusions.

Chiropractic Spinal Manipulation Prevents Secondary Hyperalgesia Induced by Topical Capsaicin in Healthy Individuals

Background and Aims: Spinal manipulation (SM) is currently recommended for the management of back pain. Experimental studies indicate that the hypoalgesic mechanisms of SM may rely on inhibition of segmental processes related to temporal summation of pain and, possibly, on central sensitization, although this remains unclear. The aim of this study was to determine whether experimental back pain, secondary hyperalgesia, and pain-related brain activity induced by capsaicin are decreased by segmental SM. Methods: Seventy-three healthy volunteers were randomly allocated to one of four experimental groups: SM at T5 vertebral level (segmental), SM at T9 vertebral level (heterosegmental), placebo intervention at T5 vertebral level, or no intervention. Topical capsaicin was applied to the area of T5 vertebra for 40 min. After 20 min, the interventions were administered. Pressure pain thresholds (PPTs) were assessed outside the area of capsaicin application at 0 and 40 min to examine secondary hyperalgesia. Capsaicin pain intensity and unpleasantness were reported every 4 min. Frontal high-gamma oscillations were also measured with electroencephalography. Results: Pain ratings and brain activity were not significantly different between groups over time (p > 0.5). However, PPTs were significantly decreased in the placebo and control groups (p < 0.01), indicative of secondary hyperalgesia, while no hyperalgesia was observed for groups receiving SM (p = 1.0). This effect was independent of expectations and greater than placebo for segmental (p < 0.01) but not heterosegmental SM (p = 1.0). Conclusions: These results indicate that segmental SM can prevent secondary hyperalgesia, independently of expectations. This has implications for the management of back pain, particularly when central sensitization is involved.

The effects of dry needling to the thoracolumbar junction multifidi on measures of regional and remote flexibility and pain sensitivity: A randomized controlled trial

BACKGROUND

Dry needling (DN) has been consistently shown to decrease pain sensitivity and increase flexibility local to the site of treatment, however it is unclear whether these effects are limited to the region of treatment or can be observed remote to the area of treatment.

OBJECTIVE

To determine the immediate, short-term effects of DN to the thoracolumbar junction on regional and remote flexibility, and to observe if changes in pain sensitivity can occur remote to site of treatment.

DESIGN

Double-blind randomized clinical trial.

METHODS

Fifty-four subjects with low back pain and decreased length in at least one hamstring were randomized to receive either DN or sham DN to the T12 and L1 multifidi. Participants underwent regional (fingertip-to-floor) and remote flexibility (passive knee extension, passive straight leg raise) and pressure pain threshold (PPT) testing of the upper and lower extremity before, immediately after and 1 day after treatment. ANCOVAs were used to analyze flexibility data, with the covariate of pre-treatment values. Paired t-tests were used for difference in remote pain sensitivity.

RESULTS

Statistically larger improvements in regional flexibility, but not remote flexibility, were observed immediately post-treatment in those who received DN than in those receiving sham DN (p = .0495; adjusted difference 1.2, 95% CI 0.002-2.3). Differences between upper and lower extremity PPT were not significant.

CONCLUSION

DN can potentially have immediate changes in regional flexibility, but effects are not sustained at 24-h follow-up. DN may not affect remote flexibility or segmental pain sensitivity.

Effectiveness of local exercise therapy versus spinal manual therapy in patients with patellofemoral pain syndrome: medium term follow-up results of a randomized controlled trial

Background

Increasing evidence has shown benefits of spinal manipulations in patients with patellofemoral pain syndrome (PFPS). There is scarcity regarding medium term effects of spinal manual therapy on outcome measures in PFPS patients. Therefore, the aim of the present study was to compare the effectiveness of local exercise therapy and spinal manual therapy for knee pain, function and maximum voluntary peak force (MVPF) velocity of the quadriceps in PFPS patients.

Methods

Forty-three patients with PFPS were randomly assigned to a local exercise or spinal manual therapy group. The local exercise group received six sessions (one session per week) of supervised training of the knee-and hip muscles with mobilization of the patellofemoral joint. The spinal manual therapy group received six interventions (one intervention per week) of high velocity low thrust manipulations at the thoracolumbar region, sacroiliac joint, and/or hip. All patients were also asked to do home exercises. Maximum, minimum and current pain were measured using the visual analogue scale. Function was assessed with the anterior knee pain scale (AKPS) and MPFV was recorded using a Biodex System 3 dynamometer. Patients were assessed before intervention, after 6 weeks of intervention and after 6 weeks of follow-up. Between-group differences at assessments were analysed by way of analysis of covariance with Bonferroni correction.

Results

Pain and functionality improved more following spinal manipulative therapy than local exercise therapy. After 6 weeks of intervention the between-group difference (local versus spinal) for maximal pain was 23.4 mm [95% CI: 9.3, 37.6; effect size (ES): 1.04] and − 12.4 [95% CI: − 20.2, − 4.7; ES: 1.00] for the AKPS. At 6 weeks of follow-up the between-group difference for maximal pain was 18.7 mm [95% CI: 1.4, 36.0; ES: 0.68] and − 11.5 [95% CI: − 19.9, − 3.3; ES: − 0.87] for the AKPS.

Conclusions

This study suggests that spinal manual therapy is more effective than local exercise therapy in improving pain and function in patients with PFPS in the medium term. We suggest for future research to investigate whether combining local exercise therapy and spinal manual therapy is more effective than either single intervention on its own.

This clinical trial study was approved by the Medical Ethics Committee METC Z under registration number NL57207.096. and registered retrospectively in ClinicalTrials.gov PRS with registration ID number NCT04748692 on the 10th of February 2021.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-021-04310-9.

Hypoalgesic Effects of Transcutaneous Electrical Nerve Stimulation Combined With Joint Manipulation: A Randomized Clinical Trial

OBJECTIVE

The objective of this study was to compare the hypoalgesic effects of isolated or combined use of transcutaneous electrical nerve stimulation (TENS) and cervical joint manipulation (JM) in asymptomatic participants.

METHODS

One hundred and forty-four healthy participants aged 18 to 30 years old were randomly assigned to 1 of 4 groups (n = 36 per group): active TENS + active JM, active TENS + placebo JM, placebo TENS + active JM, and placebo TENS + placebo JM. Active or placebo TENS was applied to the dominant forearm. JM was applied to the C6-7 segments. The pressure pain threshold was measured pre- and postintervention and after 20 minutes on the forearm and tibialis anterior of the dominant side.

RESULTS

Segmental hypoalgesia was greater in the group active TENS + active JM compared with active TENS + placebo JM (P = .002), placebo TENS + active JM (P < .0001), and placebo TENS + placebo JM (P < .0001). For the extrasegmental hypoalgesia, active TENS + active JM had greater hypoalgesic effect compared with active TENS + placebo JM (P = .033), placebo TENS + active JM (P = .002), and placebo TENS + placebo JM (P < .0001).

CONCLUSION

TENS and JM produced hypoalgesia when used alone and, when the treatments were combined, a higher segmental and extrasegmental hypoalgesic effect was obtained in asymptomatic participants.

Neurophysiological mechanisms of chiropractic spinal manipulation for spine pain

Together, neck pain and back pain are the first cause of disability worldwide, accounting for more than 10% of the total years lived with disability. In this context, chiropractic care provides a safe and effective option for the management of a large proportion of these patients. Chiropractic is a healthcare profession mainly focused on the spine and the treatment of spinal disorders, including spine pain. Basic studies have examined the influence of chiropractic spinal manipulation (SM) on a variety of peripheral, spinal and supraspinal mechanisms involved in spine pain. While spinal cord mechanisms of pain inhibition contribute at least partly to the pain-relieving effects of chiropractic treatments, the evidence is weaker regarding peripheral and supraspinal mechanisms, which are important components of acute and chronic pain. This narrative review highlights the most relevant mechanisms of pain relief by SM and provides a perspective for future research on SM and spine pain, including the validation of placebo interventions that control for placebo effects and other non-specific effects that may be induced by SM. SIGNIFICANCE: Spinal manipulation inhibits back and neck pain partly through spinal segmental mechanisms and potentially through peripheral mechanisms regulating inflammatory responses. Other mechanisms remain to be clarified. Controls and placebo interventions need to be improved in order to clarify the contribution of specific and non-specific effects to pain relief by spinal manipulative therapy.

A mixed-methods survey to explore issues with virtual consultations for musculoskeletal care during the COVID-19 pandemic

OBJECTIVE

To explore orthopaedic and musculoskeletal clinicians' views and experiences of legal, safety, safeguarding and security issues regarding the use of virtual consultations (VC) during the COVID-19 pandemic. A secondary objective was to suggest ways to overcome these issues.

METHODS

A mixed method cross-sectional survey was conducted, seeking the views and experiences of orthopaedic and musculoskeletal medically qualified and Allied Health Professionals in the United Kingdom. Descriptive statistical analysis was employed for quantitative data and a qualitative content analysis undertaken for qualitative data. Findings were presented in accordance with the four key issues.

RESULTS

Two hundred and ninety professionals (206 physiotherapists, 78 medically qualified professionals, 6 'other' therapists) participated in the survey. Of the 290 participants, 260 (90%) were not using VC prior to the COVID-19 pandemic, 248 respondents (86%) were unsure whether their professional indemnity insurance covered VC, 136 (47%) had considered how they would handle an issue of safeguarding whilst the remainder had not, 126 (43%) had considered what they would do if, during a virtual consultation, a patient suffered an injury (e.g. bang on their head) or a fall (e.g. mechanical or a medical event like syncope) and 158 (54%) reported they felt the current technological solutions are secure in terms of patient data. Qualitative data provided additional context to support the quantitative findings such as validity of indemnification, accuracy of diagnosis and consent using VC, safeguarding issues; and security and sharing of data. Potential changes to practice have been proposed to address these issues.

CONCLUSIONS

VC have been rapidly deployed since the onset of the COVID-19 pandemic often without clear guidance or consensus on many important issues. This study identified legal, safeguarding, safety and security issues. There is an urgent need to address these and develop local and national guidance and frameworks to facilitate ongoing safe virtual orthopaedic practice beyond the COVID-19 pandemic.

Spinal manipulation and modulation of pain sensitivity in persistent low back pain: a secondary cluster analysis of a randomized trial

BACKGROUND

Pain hypersensitivity can be assessed using Quantitative Sensory Testing (QST) and is associated with persistent low back pain. Spinal manipulation appears to modify pain hypersensitivity, and this could function as one mechanism leading to clinical improvements. In the current study, we applied a comprehensive QST battery to assess pain sensitivity in a cohort of low back pain patients before and after spinal manipulation to improve our understanding of the association between QST and clinical improvements. This study addresses two questions: Are clinical improvements following spinal manipulation in low back pain patients contingent on pain hypersensitivity, and does pain sensitivity change following spinal manipulation?

METHODS

We performed a secondary analysis of data from a randomized clinical trial. One hundred and thirty-two participants with persistent LBP were treated with spinal manipulation four times over two weeks. Patient-reported outcomes and QST were assessed at baseline, after the fourth spinal manipulation session, and 14-days later. The clinical outcomes were changes in low back pain intensity and disability. Using latent profile analysis, we categorized the participants into clusters depending on their baseline QST scores. We used linear mixed models to examine the association between clusters and changes in patient-reported outcomes and QST.

RESULTS

Two clusters emerged: a Sensitized and a Not sensitized. The former had significantly lower regional pressure and thermal pain thresholds, remote pressure pain tolerance, and lower inhibitory conditioned pain modulation than the Not sensitized group. However, we only found between-cluster differences for regional pressure pain threshold following spinal manipulation. Thus, the clusters were not associated with patient-reported pain and disability changes or the remaining QST outcomes.

CONCLUSIONS

We report that the baseline QST profile was not associated with clinical improvements following spinal manipulation. We did observe a substantial change for regional pressure pain threshold, which suggests that any effect of spinal manipulation on pain sensitivity is most likely to be observed as changes in regional, mechanical pain threshold. However, the mechanism that invokes clinical improvement and pain sensitivity changes appear distinct. Due to methodological caveats, we advise caution when interpreting the results.

TRIAL REGISTRATION

Clinical.Trial.gov identifier: NCT04086667 , registered 11 September 2019 - Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT04086667.

Mindfulness-based waiting room intervention for osteopathic manipulation patients: a pilot randomized controlled trial

CONTEXT

Osteopathic manipulative treatment (OMT) and mindfulness-based interventions are both efficacious pain management strategies. Combining these two therapeutic approaches may offer added benefits to pain patients.

OBJECTIVES

To determine whether engaging in a mindfulness-based intervention before an OMT session improved OMT session outcomes.

METHODS

Patients seeking OMT care from a single osteopathic physician at an integrative health clinic were recruited for this pilot randomized, controlled trial at an academic hospital. All patients scheduled for osteopathic structural evaluation and treatment with the provider from March 2019 to September 2019 were eligible and invited to participate during the reminder call before their visit. Participants were randomly assigned to listen to one of two audio recordings matched for length: (1) the history of osteopathic medicine, or (2) a guided mindfulness meditation practice. Patients completed surveys including numeric rating scales to measure mindfulness and embodied safety (a self-reported feeling that the patient's body was in a safe place) immediately before and after listening to the audio recording. A global pain rating report along with a sensation manikin (a digital human figure silhouette overlaid with a grid of 786 "sensation" pixels) capturing both pleasant and unpleasant sensation were collected before and after the OMT session. Session satisfaction was also assessed with a single survey item.

RESULTS

A total of 57 participants were enrolled in the study; however, 18 were unable to listen to the full audio recording and were excluded from further analysis. The final study sample consisted of 39 patients, with 19 (48.7%) randomized to the history audio recording and 20 (51.3%) randomized to the mindfulness recording. The mean age of patients was 57 years (standard deviation, 11.75 years); 25 (64.1%) were women and 14 (35.9%) were men. The most common primary pain location was the neck (16; 41.0%), followed by back (12; 30.8%) and joint (5; 12.8%). Twenty (51.3%) participants were cancer patients; 19 (48.8%) did not have a cancer diagnosis. Practicing mindfulness before OMT increased patients' sense of mindful connection to (p=0.036) and safety within (p=0.026) their bodies as well as their overall session satisfaction (p=0.037). Additionally, OMT paired with either study condition (mindfulness vs. history) decreased pain (p<0.001) and increased the ratio of pleasant to unpleasant sensations reported by patients (p<0.001). Finally, regardless of experimental condition (mindfulness vs. history), increased safety within the body predicted greater pain relief (β=-0.33, p=0.035) and larger sensation ratio changes (β=0.37, p=0.030) at the OMT session's end. Additionally, increased mindful connection to the body predicted less pain (β=-0.41, p=0.005) at the session's end.

CONCLUSIONS

This study demonstrated the feasibility of integrating a mindfulness-based intervention with OMT and results suggest that having patients listen to an audio-guided mindfulness practice while waiting for their OMT session may increase their mindful connection to and safety within their bodies as well as their session satisfaction. This study also provides empirical evidence that OMT may increase the distribution of pleasant sensations reported by pain patients while decreasing the distribution of unpleasant sensations reported.

Characteristics and treatment of geriatric patients in an osteopathic neuromusculoskeletal medicine clinic

CONTEXT

Osteopathic manipulative medicine (OMM) is an adjunctive treatment approach available to geriatric patients, but few studies provide details about presenting conditions, treatments, and response to osteopathic manipulative treatment (OMT) in that patient population.

OBJECTIVES

To provide descriptive data on the presentation and management of geriatric patients receiving OMT at an outpatient osteopathic neuromusculoskeletal medicine (ONMM) clinic.

METHODS

Data were retrospectively collected from electronic health records (EHR) at a single outpatient clinic for clinical encounters with patients over 60 years of age who were treated with OMT between July 1, 2016, and June 30, 2019. Records were reviewed for demographic information, insurance type, presenting concerns, assessments, regions treated, OMT techniques used, and treatment response.

RESULTS

There were 9,155 total clinical encounters with 1,238 unique patients found during the study period. More women than men were represented for overall encounters (6,910 [75.4%] vs. 2,254 [24.6%]) and unique patients (850 [68.7%] vs. 388 [31.3%]; both p<0.001). The mean (standard deviation, SD) number of encounters per patient per year was 4.5 (4.0) and increased with increasing age by decade (p<0.001). Medicare was the most common primary insurance (7,246 [79.2%]), with private insurance the most common secondary insurance (8,440 [92.2%]). The total number of presenting concerns was 12,020, and back concerns were most common (6,406 [53.3%]). The total number of assessments was 18,290; most were neuromusculoskeletal (17,271 [94.5%]) and in the thoracolumbar region (7,109 [38.9%]). The mean (SD) number of somatic dysfunction assessments per encounter was 5 (1.7); the thoracic region was the most documented and treated (7,263 [15.8%]). With up to 19 technique types per encounter, the total number of OMT techniques documented across all encounters was 43,862, and muscle energy (7,203 [16.4%]) was the most documented. The use of high-velocity, low-amplitude (HVLA) declined as age increased (p<0.001). The overall treatment response was documented in 7,316 (79.9%) encounters, and most indicated improvement (7,290 [99.6%]).

CONCLUSIONS

Our results showed that geriatric patients receiving OMT at our clinic were predominately presenting for neuromusculoskeletal concerns associated with back, neck, and extremity conditions, consistent with national epidemiological data for this population. The most common OMT techniques were also consistent with those used nationally by osteopathic medical students and practicing physicians. Future longitudinal studies are needed to determine the length of time improvement persists and the overall health impact experienced by geriatric patients receiving OMT.

The comparative effects of spinal manipulation, myofascial release and exercise in tension-type headache patients with neck pain: A randomized controlled trial

OBJECTIVES

To evaluate the effects of two manual treatment methods on pain, disability, and pressure pain threshold (PPT) in tension-type headache (TTH) patients with and neck pain.

METHODS

Forty-five patients with TTH were randomly assigned to one of three groups and received eight sessions treatment: manipulation plus exercise (manipulation), suboccipital inhibition plus exercise (myofascial release), and exercise only (control). Headache frequency, pain severity (VAS-headache, VAS-neck pain) and headache and neck disability (HIT-6 and NDI, respectively) were measured at baseline, posttreatment, and at the third month follow-up. PPT was also evaluated on the temporalis muscle.

RESULTS

Manipulation group was statistically better than myofascial release group in terms of headache frequency, headache severity, and PPT scores. Also, manipulation group showed statistically significant improvements in all outcome criteria when compared control group.

CONCLUSIONS

Manipulation and exercise, in addition to pharmacologic treatment in TTH patients with cervical dysfunction appear to be a promising approach.

Changes in pain sensitivity and spinal stiffness in relation to responder status following spinal manipulative therapy in chronic low Back pain: a secondary explorative analysis of a randomized trial

Background

In a prior randomized trial, we demonstrated that participants receiving spinal manipulative therapy at a pain-sensitive segment instead of a stiff segment experienced increased mechanical pressure pain thresholds. We hypothesized that the targeted segment mediated this increase through a segment-dependent neurophysiological reflective pathway. Presently, it is not known if this decrease in pain sensitivity is associated with clinical improvement. Therefore, we performed an explorative analysis to examine if changes in experimental pain sensitivity (mechanical and thermal) and lumbar stiffness were further dependent on clinical improvement in disability and patient-reported low back pain.

Methods

This study is a secondary explorative analysis of data from the randomized trial that compared 132 participants with chronic low back pain who received lumbar spinal manipulative therapy applied at either i) the stiffest segment or ii) the segment having the lowest pain threshold (i.e., the most pain-sensitive segment). We collected data at baseline, after the fourth session of spinal manipulation, and at 14-days follow-up. Participants were dichotomized into responders/non-responders using different clinical variables (disability and patient-reported low back pain) with varying threshold values (0, 30, and 50% improvement). Mixed models were used to assess changes in experimental outcomes (stiffness and pain sensitivity). The fixed interaction terms were time, segment allocation, and responder status.

Results

We observed a significant increase in mechanical pressure pain thresholds for the group, which received spinal manipulative therapy at the most pain-sensitive segment independent of whether they improved clinically or not. Those who received spinal manipulation at the stiffest segment also demonstrated increased mechanical pain sensitivity, but only in the subgroup with clinical improvement. We did not observe any changes in lumbar stiffness.

Conclusion

Our results suggest the existence of two different mechanistic pathways associated with the spinal manipulation target. i) A decrease of mechanical pain sensitivity independent of clinical outcome (neurophysiological) and ii) a decrease as a reflection of the clinical outcome. Together, these observations may provide a novel framework that improves our understanding of why some respond to spinal manipulative therapy while others do not.

Trial registration

ClinicalTrials.gov identifier: NCT04086667 registered retrospectively September 11th 2019.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-020-03873-3.

Pain sensitivity is reduced by exercise training: Evidence from a systematic review and meta-analysis

BELAVY, D. L., J. Van Oosterwijck, M. Clarkson, E. Dhondt, N. L. Mundell, C. Miller and P. J. Owen. NEUROSCI BIOBEHAV REV 21(1) XXX-XXX, 2020. Exercise training is capable of reducing pain in chronic pain syndromes, yet its mechanisms are less well established. One mechanism may be via the impact of exercise on increasing a person's pain threshold. Here we show, via meta-analysis of fifteen exercise training studies in pain syndromes that exercise training leads to increased pressure pain thresholds (low to moderate quality evidence). We also find low to moderate quality evidence exists that exercise training was more effective than non-exercise interventions, such as pain education, massage and stress management for improving pain sensitivity. Further, the effect of exercise was greater locally at the site of pain and less so at remote regions. These finding suggest that adaptations in central inhibition occur over time with exercise training and, more widely, add to the mechanistic understanding of how effective interventions can improve pain in chronic pain syndromes.

The Acute Effects of Manual and Instrument-Assisted Cervical Spine Manipulation on Pressure Pain Threshold, Pressure Pain Perception, and Muscle-Related Variables in Asymptomatic Subjects: A Randomized Controlled Trial

OBJECTIVE

The purpose of this study was to compare the immediate effects in asymptomatic participants of manual and instrument-assisted cervical manipulation on pressure pain thresholds, pressure pain perception, and muscle mechanical properties (tone, stiffness, and elasticity) over muscles anatomically related and unrelated to the manipulated level.

METHODS

Fifty-nine asymptomatic participants (34 women and 25 men; age [mean ± standard deviation] = 21.1 ± 1.6 years) were randomly assigned to 4 groups in a double-blind, randomized, placebo-controlled trial. Two groups received cervical (C3/C4) manipulation, 1 manual and the other instrument-assisted; the third group received a sham manipulation; and the fourth group served as the control. Bilateral pressure pain threshold, pressure pain perception, muscle tone, stiffness, and elasticity in the upper trapezius and biceps brachii were evaluated before and immediately after the interventions.

RESULTS

At baseline, there were no differences among the groups on any variable. After the interventions, a significant increase in pressure pain threshold was observed with both manual and instrument-assisted manipulation at local and distal sites (P < .05), whereas no changes were observed in either the control or the placebo group. The perception of pain pressure did not change significantly in any group. The interventions did not promote any statistically significant differences in muscle tone, elasticity, or stiffness at any site (local or distal).

CONCLUSION

Cervical (C3/C4) manual and instrument-assisted manipulations produced an increase in pressure pain threshold bilaterally and over muscles related and unrelated to the vertebral segment, but had no effect on muscle tone, elasticity, or stiffness.

Immediate effects of cervicothoracic junction mobilization versus thoracic manipulation on the range of motion and pain in mechanical neck pain with cervicothoracic junction dysfunction: a pilot randomized controlled trial

Background

Cervicothoracic (CT) junction hypomobility has been proposed as a contributing factor for neck pain. However, there are limited studies that compared the effect of CT junction mobilization against an effective intervention in neck pain. Thoracic spine manipulation is a nonspecific intervention for neck pain where remote spinal segments are treated based on the concept of regional interdependence. The effectiveness of segment-specific spinal mobilization in the cervical spine has been researched in the last few years, and no definite conclusions could be made from the previous studies. The above reasons warrant the investigation of the effects of a specific CT junction mobilization against a nonspecific thoracic manipulation intervention in neck pain. The present study aims to compare the immediate effects of C7-T1 Maitland mobilization with thoracic manipulation in individuals with mechanical neck pain presenting with CT junction dysfunction specifically.

Methods

A randomized clinical trial is conducted where participants with complaints of mechanical neck pain and CT junction dysfunction randomly assigned to either C7-T1 level Maitland mobilization group or mid-thoracic (T3-T6) manipulation group (active control group). In both the groups, the post graduate student (SJ) pursuing Master’s in orthopedic physiotherapy delivered the intervention. The outcomes of cervical flexion, extension, side flexion & rotation range of motion (ROM) were measured before & after the intervention with a cervical range of motion (CROM) device. Self-reported pain intensity was measured with the numerical pain rating scale (NPRS). The post-intervention between-group comparison was performed using a one-way ANCOVA test.

Results

Forty-two participants with mean age CT junction group: 35.14 ± 10.13 and Thoracic manipulation group: 38.47 ± 11.47 were recruited for the study. No significant differences in the post-intervention baseline adjusted outcomes of cervical ROM & self-reported pain intensity were identified between the groups after the treatment (p = 0.08, 0.95, 0.01, 0.39, 0.29, 0.27for flexion, extension, bilateral lateral flexion & rotations respectively) & neck pain intensity (p = 0.68). However, within-group, pre, and post comparison showed significant improvements in cervical ROM and pain in both groups.

Conclusion

This preliminary study identified that CT junction mobilization is not superior to thoracic manipulation on the outcomes of cervical ROM and neck pain when level-specific CT junction mobilization was compared with remote mid-thoracic manipulation in individuals with mechanical neck pain and CT junction dysfunction.

Trial registration

CTRI: 2018/04/013088, Registered 6 April 2018, http://ctri.nic.in/Clinicaltrials/pmaindet2.php?trialid=24418

Toward a Theory of the Mechanism of High-Velocity, Low-Amplitude Technique: A Literature Review

This review seeks to integrate the current literature to create a more unified and inclusive theory regarding the therapeutic mechanism of high-velocity, low-amplitude (HVLA) technique. The authors review the literature currently available regarding the physiologic effects of HVLA. The progression from an articulatory model to a neuromuscular one is discussed, and the body of work demonstrating that HVLA has a centralized mechanism of action, rather than just a local one, is described.