Immediate effects on electromyographic activity and pressure pain thresholds after a cervical manipulation in mechanical neck pain: a randomized controlled trial

The majority of clinical trials assessing mobilization and manipulation for neck pain lack a pragmatic approach: a systematic review of 174 trials

BACKGROUND

Disorders of the cervical spine are some of the costliest musculoskeletal conditions to manage globally. Joint mobilization and manipulation have been shown to be an effective treatment for neck pain. However, the generalizability and clinical translation depends on the nature of the trial designs that inform its use. The extent to which randomized control trials (RCTs) assessing manual therapy treatments for cervical spine disorders fall on the efficacy (explanatory) -effectiveness (pragmatic) spectrum often informs how the findings are translated into clinical practice.

OBJECTIVE

The aim of this systematic review was to determine where RCTs of manual therapy for neck disorders fall on the efficacy-effectiveness spectrum.

METHODS

A search of three electronic databases including PubMed, CINAHL, and CENTRAL were completed for trials published from inception to May 2023. RCTs in which joint mobilization or manipulation were used to treat cervical spine disorders were assessed on the effectiveness-efficacy spectrum using the Rating of Included Trials on the Efficacy-Effectiveness Spectrum (RITES) tool and risk of bias using the Revised Cochrane Risk of Bias tool.

RESULTS

A total of 174 trials met eligibility. RITES domain two trial setting (71.3% vs 16.1%), domain three flexibility of intervention(s) (62.1% vs 23%), and domain four clinical relevance of experimental and comparison intervention(s) (51.7% vs 29.3%) all favored efficacy over effectiveness. Domain one participant characteristic(s) had a slightly greater emphasis on effectiveness compared to efficacy (36.8% vs 44.8%). Most studies (96%) had at least some risk of bias.

CONCLUSION

Over half of the RCTs assessing the treatment effect of joint mobilization and manipulation for neck pain favor efficacy (explanatory) over effectiveness (pragmatic) designs. Future RCTs on this topic should consider a greater emphasis on pragmatic trial design components in order to better reflect real-world translation to clinical practice.

Associations of Treatment Outcome Expectations and Pain Sensitivity after Cervical Spine Manipulation in Patients with Chronic Non-Specific Neck Pain: A Cohort Study

(1) Background: This cohort study aimed to evaluate the effect of patients' treatment expectations on pain perception changes following manual therapy cervical manipulations in individuals with chronic mechanical neck pain. (2) Methods: Demographic data were collected by 56 subjects who were asked to fill out the Neck Disability Index (NDI) and the Expectations for Treatment Scale (ETS). All patients received one single cervical manipulation, and pressure pain thresholds (PPTs) were measured before and immediately after the manipulation with a digital algometer. (3) Results: A total of 56 patients participated. Most subjects (62.5%) had high treatment expectations according to the ETS scale. Statistically significant increases in PPTs were noted both locally and in remote areas (p < 0.05), with 37.5-48.2% of participants showing clinically significant changes in pain perception. However, no statistically significant correlation was found between high treatment expectations and increased PPTs (p > 0.05). (4) Conclusions: Although a significant reduction in pain perception was observed, it did not correlate with patients' treatment expectations. Future research for further investigation of this hypothesis by comparing real versus sham treatment and exploring additional mechanisms affecting changes in PPTs after cervical manipulations in this population will contribute to a better understanding of the research question.

Combined Effects of Glenohumeral Mobilization, Stretching, and Thoracic Manipulation on Shoulder Internal Rotation Range of Motion

Background/purpose

Interventions including posterior glenohumeral mobilizations (PGM), sleeper stretches, and thoracic manipulation are commonly used to address posterior shoulder tightness. The purpose of this study was to assess the effects of adding thoracic manipulation to PGM and sleeper stretches on passive range of motion (PROM), joint mobility, and infraspinatus electromyographic (EMG) activity in shoulders with decreased internal rotation (IR) PROM.

Design

Randomized Sequential Intervention Laboratory Study.

Methods

Forty individuals with clinically significant IR loss attended two study sessions. Participants were randomized to receive five 30 seconds bouts of either grade III PGM or sleeper stretching. Following a seven-day washout period, all participants attended a second session and received a prescriptive supine HVLA manipulation targeting the T3-4 segment, followed by the previously randomized intervention. Outcome measures included internal rotation PROM, horizontal adduction PROM, posterior glenohumeral joint translation assessed via ultrasound imaging, and EMG activity of the infraspinatus during a PGM. All outcome measures were assessed pre- and immediately post-intervention and compared statistically.

Results

There were significant within-group, but not between-group, differences for IR and horizontal adduction PROM following a single session of PGM or sleeper stretch. When combined with thoracic manipulation, significantly smaller within session changes of IR PROM were observed for both PGM (mean difference 4.4, p=0.017) and sleeper stretches (mean difference 6.4, p=0.0005). There were no significant between group differences for horizontal adduction PROM, humeral head translation, or EMG activity across all time points.

Discussion

Both GH posterior mobilizations and sleeper stretches improved IR and horizontal adduction PROM in a single session. The addition of thoracic manipulation prior to local shoulder interventions resulted in smaller gains of both IR and horizontal adduction ROM.

Level of evidence

Level 2.

Chiropractic spinal manipulative therapy for acute neck pain: A 4-arm clinical placebo randomized controlled trial. A prospective study protocol

INTRODUCTION

Neck pain poses enormous individual and societal costs worldwide. Spinal manipulative therapy and Non-Steroidal Anti-Inflammatory Drug treatment are frequently used despite a lack of compelling efficacy data. This protocol describes a multicentre 4-arm, clinical placebo randomized controlled trial (RCT), investigating the efficacy of chiropractic spinal manipulative therapy (CSMT) versus sham CSMT, ibuprofen, and placebo medicine for acute neck pain. This superiority study will employ parallel groups, featuring a 1:1:1:1 allocation ratio.

MATERIAL AND METHODS

We will randomize 320 participants equally into four groups: CSMT, sham CSMT, ibuprofen, or placebo medicine. CSMT groups are single-blinded, while the medicine groups are double-blinded. Data will be collected at baseline (Day 0), during treatment and post-treatment. The primary endpoint will assess the difference in mean pain intensity from Day 0 to Day 14 on a numeric rating scale 0-10; the CSMT group is compared to sham CSMT, ibuprofen, and placebo medicine groups, respectively. Secondary endpoints will assess mean pain intensity and mean duration at different time points, and adverse events, blinding success, and treatment satisfaction, including comparison between ibuprofen and placebo medicine. Power calculation is based on a mean neck pain rating of 5 at Day 0, with standard deviation of 1 in all groups. Mean pain reduction at Day 14 is expected to be 60% in the CSMT group, 40% in sham CSMT and ibuprofen groups, and 20% in the placebo medicine group. A linear mixed model will compare the mean values for groups with corresponding 95% confidence intervals. P values below 0.017 will be considered statistically significant. All analyses will be conducted blinded from group allocation.

DISCUSSION

This RCT aims towards the highest research standards possible for manual-therapy RCTs owing to its two placebo arms. If CSMT and/or ibuprofen proves to be effective, it will provide evidence-based support for CSMT and/or ibuprofen for acute neck pain.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT05374057. EU Clinical Trials Register: EudraCT number: 2021-005483-21.

The effect of lumbar spinal manipulation on biomechanical factors and perceived transient pain during prolonged sitting: a laboratory-controlled cross-sectional study

BACKGROUND

Spinal manipulation has been shown to affect muscle activity, posture, and pain. To date, no studies have examined the effect of manipulation on biomechanical factors during sitting. Therefore, the purpose of this study was to investigate the immediate effect of lumbar spinal manipulation on trunk muscle activation, spine posture and movements, and perceived ratings of transient pain in asymptomatic adults during prolonged office sitting.

METHODS

Twenty healthy adults were recruited for a single laboratory session that included a standardized office sitting/data entry protocol (120 min total, 3 blocks of 40 min). Data were collected between July and August 2012. The first block (baseline) was immediately followed by two experimental blocks. Prior to the start of each experimental block, participants were transferred to a therapy plinth and placed side lying (right side down), and a random presentation of either a control or high velocity low amplitude thrust directed at L4/L5 was delivered. Continuous measures of muscle activity, spine posture, and spine movements were recorded throughout the sitting trials. Perceived transient pain was measured by visual analogue scale at 10-min intervals (including immediately before and after the randomized maneuvers).

RESULTS

There were no significant differences in spine or pelvic posture or perceived back pain following either the manipulation or control maneuvers. Significantly reduced muscle activity and increased shifts of the lumbar spine angle were identified in the block following manipulation compared to both baseline and post control blocks.

CONCLUSIONS

Spinal manipulation does not appear to have an immediate impact on spine or pelvic posture in healthy adults but does appear to reduce muscle activity and increase spine movement during sitting. Future work should replicate this study with a larger population in a field setting. It may be worthwhile to explore the implication of reduced muscle activation and increased spine movements during prolonged sitting for office workers that receive manipulations or mobilizations during their workday.

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.

Effects of Global Postural Reeducation versus Specific Therapeutic Neck Exercises on Pain, Disability, Postural Control, and Neuromuscular Efficiency in Women with Chronic Nonspecific Neck Pain: Study Protocol for a Randomized, Parallel, Clinical Trial

Background: Chronic nonspecific neck pain is the most frequent form of neck pain. It is more prevalent in women, and a costly public health issue. It is commonly associated with biomechanical, functional, proprioceptive, and postural impairments. The aim of this trial is to compare the effects of global postural exercises versus specific therapeutic exercises on neck pain, disability, mobility, pressure pain threshold, kinesiophobia, pain catastrophizing, postural control, and neuromuscular efficiency in women with chronic nonspecific neck pain. Methods and analysis: This study is a randomized, parallel-group and single blinded clinical trial. Sixty-two women with nonspecific chronic neck pain were recruited from the community of Guarda, Portugal, and randomly assigned to one of two intervention groups: (1) global postural reeducation (GPR group), (2) specific therapeutic exercises (STE group). The intervention was carried out over 4 weeks, with two sessions per week (eight sessions), and applied by a physiotherapist and paired with a daily individual at-home-exercise program. Primary outcomes are neck pain intensity and disability (Numerical Pain Rating Scale, Neck Disability Index). Secondary outcomes are cervical mobility and pressure pain threshold (CROM, algometry), attitude to pain (kinesiophobia, pain catastrophizing), standing postural control (Center of Pressure (COP) displacements), and neuromuscular efficiency (electromyography). There are four points of evaluation where the outcomes were assessed twice before the intervention, 1 week apart, and the two post-intervention assessments will be carried out after four and eight sessions. The objective was to increase scientific knowledge of different exercise modalities, such as global postural reeducation, in musculoskeletal disorders. Trial registration: ClínicalTrials.gov (NCT04402463), prospectively registered (data 22 May 2020).

Effects of Instrumental, Manipulative and Soft Tissue Approaches for the Suboccipital Region in Subjects with Chronic Mechanical Neck Pain. A Randomized Controlled Trial

The INYBI is an instrument used to release the suboccipital myofascial area. There is scarce evidence of its efficacy. A randomized controlled, double-blinded, longitudinal and prospective trial was performed. Ninety-six subjects (aged 29.47 ± 5.16 years) (70 women) with chronic neck pain were randomly assigned to the manual suboccipital inhibition technique (MSIT), instrumental suboccipital inhibition (INYBI) or the INYBI plus upper cervical manipulation technique (INYBI + UCMT) groups and received two sessions with a week interval between them. The Neck Disability Index was used before the first intervention and two weeks after the second intervention. Pre- and post-measurements were taken on both intervention days for pressure pain threshold of the upper trapezius and suboccipital muscles, self-perceived pain and cervical range of motion. In spite of a significant general improvement in time that was found for the three groups for all of the outcome measurements (p < 0.05 in all cases), no between-groups differences were found (p > 0.05 in all cases), with the exception of self-perceived pain for left rotation (p = 0.024), with the MSIT group showing the lower improvement. However, the higher degree of within-group improvements was found for the INYBI + UCMT group. It was concluded that the myofascial release therapy in the suboccipital area is effective in patients with chronic neck pain, either through a manual application or by means of the INYBI tool. Moreover, the addition of craniocervical manipulation achieved the higher within-group improvements, but with no statistical significance.

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.

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.

The Association Between Conditioned Pain Modulation and Manipulation-induced Analgesia in People With Lateral Epicondylalgia

OBJECTIVES

Conditioned pain modulation (CPM) and manipulation-induced analgesia (MIA) may activate similar neurophysiological mechanisms to mediate their analgesic effects. This study assessed the association between CPM and MIA responses in people with lateral epicondylalgia.

MATERIALS AND METHODS

Seventy participants with lateral epicondylalgia were assessed for CPM followed by MIA. A single assessor measured pressure pain thresholds (PPT) before, during, and after cold water immersion (10°C) of the asymptomatic hand and contralateral lateral glide (CLG) mobilization of the neck. For analyses, linear mixed models evaluated differences in CPM and MIA responses. Pearson partial correlations and regression analyses evaluated the association between CPM and MIA PPT.

RESULTS

There was a significant increase (CPM and MIA, P<0.001) in PPT from baseline during the interventions (CPM mean: 195.84 kPa for elbow and 201.87 kPa for wrist, MIA mean: 123.01 kPa for elbow and 126.06 kPa for wrist) and after the interventions (CPM mean: 126.06 kPa for elbow, 114.24 kPa for wrist, MIA mean: 123.50 kPa for elbow and 122.16 kPa for wrist). There were also significant moderate and positive partial linear correlations (r: 0.40 to 0.54, P<0.001) between CPM and MIA measures, controlling for baseline measures. Regression analyses showed that CPM PPT was a significant predictor of MIA PPT (P<0.001) and the models explained between 73% and 85% of the variance in MIA PPT.

DISCUSSION

This study showed that CPM and MIA responses were significantly correlated and that the CPM response was a significant predictor of MIA response.

The Effect of High Velocity Low Amplitude Cervical Manipulations on the Musculoskeletal System: Literature Review

In manual therapy, high velocity low amplitude (HVLA) cervical manipulation techniques are frequently used, but often the physiological and biomechanical effects that can be obtained are not completely clear. The techniques are mostly used for the treatment of biomechanical joint dysfunction, but little is yet known about the possibility of using them in order to achieve better performance on healthy subjects. The objective of the study is to describe how cervical manipulation can impact on a musculoskeletal disorder.

A systematic search was carried out on the Pubmed electronic database from the beginning of January to March 2020. Two independent reviewers conducted the screening process through the PRISMA diagram to determine the eligibility of the articles. The inclusion criteria covered randomized controlled trial (RCT) manuscripts published in peer-reviewed journals with individuals of all ages from 2005 to 2020. The included intervention was thrust manipulation or HVLA directed towards the cervical spine region. After reviewing the literature, 21 of 74 articles were considered useful and relevant to the research question.

The results of the research show that HVLA techniques, on subjects with musculoskeletal disorders, are able to influence pain modulation, mobility and strength both in the treated area and at a distance. Cervical manipulations are effective in management of cervicalgia, epicondylalgia, temporomandibular joint disorders and shoulder pain. With regard to results on strength in healthy subjects, given the divergent opinions of the authors, we cannot yet state that manipulation can significantly influence this parameter.

Cervical manipulations can also have risks for the patient if applied when not appropriate but the frequency of complications due to vertebral manipulation are very low. However, the manipulation techniques might be limited by low patients tolerance or the presence of contraindications. In addition, the optimal number of manipulations to be performed and the long-term benefits produced are unknown.

Completeness of the description of manipulation and mobilisation techniques in randomized controlled trials in neck pain; A review using the TiDieR checklist

STUDY DESIGN

A secondary analysis of a systematic review.

BACKGROUND

Manipulations or mobilizations are commonly used interventions in patients with mechanical neck pain. The treatment effects have often been studied in randomized controlled trials (RCT) which are generally considered the gold standard in evaluating the treatment effects, mainly due to its high internal validity. External validity is defined as the extent to which the effects can be generalised to clinical practice. An important prerequisite for this is that interventions used in clinical trials can be replicated in clinical practice. It can be questioned if interventions utilized in randomized controlled trials can be translated into clinical practice.

OBJECTIVES

The overall aim of this study is to examine whether the quality of the description of manipulation and mobilization interventions is sufficient for to replication of these interventions in clinical practice.

METHODS

A comprehensive literature search was performed. Two independent researchers used the Template for Intervention Description and Replication (TIDieR) which is a 12-item checklist for describing the completeness of the interventions.

RESULTS

Sixty-seven articles were included that used manipulation and/or mobilization interventions for patients with mechanical neck pain. None of the articles describe the intervention e.g. all the items on the TIDieR list. Considering item 8 (a-f) of the TIDieR checklist only one article described the used techniques completely.

CONCLUSION

Manipulation or a mobilization interventions are poorly reported in RCTs, which jeopardize the external validity of RCTs, making it difficult for clinicians and researchers to replicate these interventions.

The effects of spinal manipulative therapy on lower limb neurodynamic test outcomes in adults: a systematic review

Objective: Spinal Manipulative Therapy (SMT) is a routinely applied treatment modality for various musculoskeletal conditions, including low back pain. The precise mechanisms by which SMT elicits its effects are largely unknown, but recent research supports a multi-system explanation recognizing both biomechanical and neurophysiological mechanisms. Although the evaluation of changes in clinical presentation is complex, objective neurophysiological measures of sensitivity to movement (e.g. neurodynamic tests) can be a valuable clinical indicator in evaluating the effects of SMT. This review aimed to synthesize current literature investigating the effects of SMT on lower limb neurodynamics.Method: Eight electronic databases were systematically searched for randomized controlled trials (RCT) that applied SMT (against any control) and evaluated lower limb neurodynamics (Passive Straight Leg Raise or Slump Test). Selection and data extraction were conducted by one researcher, reviewed by a second author. Risk of bias (RoB) was assessed using the Cochrane Back Review Group criteria.Results: Eight RCTs were included, one with high RoB. SMT produced a clinically meaningful (≥6⁰) difference in five of these studies compared with inert control, hamstring stretching, and as an adjunct to conventional physiotherapy, but not compared with standard care, as an adjunct to home exercise and advice, or when comparing different SMT techniques. Findings compared to sham were mixed. When reported, effects tentatively lasted up to 6 weeks post-intervention.Conclusion: Limited evidence suggests SMT-improved range of motion and was more effective than some other interventions. Future research, using standardized Neurodynamic tests, should explore technique types and evaluate longer-term effects.Level of Evidence: 1a.

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.

Pain neuroscience education plus exercise compared with exercise in university students with chronic idiopathic neck pain

Background/Aims

Neck pain is a common complaint. Its prevalence is particularly high in university students. This study examined the effects of pain neuroscience education plus exercise when compared with exercise only in university students with chronic idiopathic neck pain.

Methods

University students with chronic neck pain were randomly allocated to receive pain neuroscience education plus exercise, or exercise only intervention, and assessed at baseline, after the intervention and at 3-month follow-up. Pain intensity (primary outcome), disability, fear of movement, catastrophising, knowledge of pain neurophysiology, pressure pain thresholds and neck and scapular muscle endurance were measured to determine the impact of the interventions.

Results

It was found that disability (F=17.3, P<0.001; partial eta2=0.48), fear of movement (F=5.3, P=0.009; partial eta2=0.22), catastrophising (F=16.4, P<0.001; partial eta2=0.48) and neck extensor endurance (F=11.0, P=0.002; partial eta2=0.19) changed significantly over time. There was a significant increase in neurophysiology of pain questionnaire score for the group receiving pain neuroscience education plus exercise but not for the group receiving exercise only (group vs time interaction: F=19.8, P<0.001; partial eta2=0.51). No other significant differences were found.

Conclusions

Pain neuroscience education plus exercise has comparable results to exercise only, with the exception of knowledge about pain neurophysiology. The impact of this difference needs to be explored in future studies.

Manipulation-induced hypoalgesia in musculoskeletal pain populations: a systematic critical review and meta-analysis

Background

Manipulation-induced hypoalgesia (MIH) represents reduced pain sensitivity following joint manipulation, and has been documented in various populations. It is unknown, however, whether MIH following high-velocity low-amplitude spinal manipulative therapy is a specific and clinically relevant treatment effect.

Methods

This systematic critical review with meta-analysis investigated changes in quantitative sensory testing measures following high-velocity low-amplitude spinal manipulative therapy in musculoskeletal pain populations, in randomised controlled trials. Our objectives were to compare changes in quantitative sensory testing outcomes after spinal manipulative therapy vs. sham, control and active interventions, to estimate the magnitude of change over time, and to determine whether changes are systemic or not.

Results

Fifteen studies were included. Thirteen measured pressure pain threshold, and four of these were sham-controlled. Change in pressure pain threshold after spinal manipulative therapy compared to sham revealed no significant difference. Pressure pain threshold increased significantly over time after spinal manipulative therapy (0.32 kg/cm², CI 0.22–0.42), which occurred systemically. There were too few studies comparing to other interventions or for other types of quantitative sensory testing to make robust conclusions about these.

Conclusions

We found that systemic MIH (for pressure pain threshold) does occur in musculoskeletal pain populations, though there was low quality evidence of no significant difference compared to sham manipulation. Future research should focus on the clinical relevance of MIH, and different types of quantitative sensory tests.

Trial registration

Prospectively registered with PROSPERO (registration CRD42016041963).

Gua Sha therapy for chronic low back pain: A randomized controlled trial

OBJECTIVE

To test the efficacy of Gua Sha therapy in patients with chronic low back pain.

METHODS

50 patients with chronic low back pain (78% female, 49.7 ± 10.0 years) were randomized to two Gua Sha treatments (n = 25) or waitlist control (n = 25). Primary outcome was current pain intensity (100-mm visual analog scale); secondary outcome measures included function (Oswestry Disability Index), pain on movement (Pain on Movement Questionnaire), perceived change in health status, pressure pain threshold, mechanical detection threshold, and vibration detection threshold.

RESULTS

After treatment, patients in the Gua Sha group reported lower pain intensity (p < 0.001) and better overall health status (p = 0.002) compared to the waitlist group. No further group differences were found. No serious adverse events occurred.

CONCLUSIONS

Gua Sha appears to be an acceptable, safe, and effective treatment for patients with chronic low back pain. Further rigorous studies are needed to confirm and extend these results.

The immediate and 1-week effects of mid-thoracic thrust manipulation on lower extremity passive range of motion

BACKGROUND

Research suggests that spinal manipulation may effect motion. Less clear is whether this effect is limited to localized responses or may involve generalizable changes. Objective: To determine whether Mid-thoracic manipulation (MTM) would result in a significant change in the lower extremity passive straight leg raise (PSLR) range of motion immediately and after 1 week. Methods: Twenty-three healthy subjects were randomly assigned in a double-blinded study. An experimental group received MTM and a control group received a sham intervention. PSLR measurements were taken prior to, immediately after, and one week after the intervention. Results: Mixed model repeated measure analysis of variance was used to determine that there was a significant interaction between MTM and time (F(2, 21) = 3.84, p < 0.05). Post hoc tests revealed a significant difference between the pretest to immediate posttest values (p < 0.05, SE = 1.47). PSLR in the MTM group increased 10.3° while the sham group increased 1.9°. Difference was non-significant between pretest and 1-week follow-up (p = 0.129, SE = 2.46). Conclusions: MTM may immediately increase lower extremity passive range of motion, but the effect was lost by the 1-week follow-up. This supports evolving research suggesting that spinal manipulation may have a generalized but transient physiological effect.

The clinical reasoning process in randomized clinical trials with patients with non-specific neck pain is incomplete: A systematic review

OBJECTIVE

Primarily to evaluate the completeness of the description of the clinical reasoning process in RCTs with patients with non-specific neck pain with an argued or diagnosed cause i.e. an impairment or activity limitation. Secondly, to determine the association between the completeness of the clinical reasoning process and the degree of risk of bias.

DATA SOURCES

Pubmed, Cinahl and PEDro were systematically searched from inception to July 2016.

STUDY SELECTION

RCTs (n = 122) with patients with non-specific neck pain receiving physiotherapy treatment published in English were included.

DATA EXTRACTION

Data extraction included study characteristics and important features of the clinical reasoning process based on the Hypothesis-Oriented Algorithm for Clinicians II (HOAC II)].

DATA SYNTHESIS

Thirty-seven studies (30%) had a complete clinical reasoning process of which 8 (6%) had a 'diagnosed cause' and 29 (24%) had an 'argued cause'. The Spearmans rho association between the extent of the clinical reasoning process and the risk of bias was -0.2.

CONCLUSIONS

In the majority of studies (70%) the described clinical reasoning process was incomplete. A very small proportion (6%) had a 'diagnosed cause'. Therefore, a better methodological quality does not necessarily imply a better described clinical reasoning process.

Short-term effects of manipulative treatment versus a therapeutic home exercise protocol for chronic cervical pain: A randomized clinical trial

BACKGROUND

While both manipulative treatment and physical exercises are used to treat cervical pain, it remains unclear which is most effective.

OBJECTIVE

To compare the short-term effects of high-velocity, low-amplitude manipulation techniques (MT) with those of home-exercise (HE) with stretching and low-intensity (10% of max) isometric contractions on pain and function.

METHODS

Single-blind randomized clinical trial was performed. A total of 27 asymptomatic subjects were randomly assigned to 2 groups: manipulation techniques (MT, n= 13) and home exercise (HE, n= 14). The visual analogue scale (VAS); neck disability index (NDI); pressure pain thresholds; cervical spine range of motion and electromyography during the cranio-cervical flexion test was measured before and one week after the intervention.

RESULTS

After the intervention, both groups showed improved (P< 0.05) NDI and VAS scores and flexion in both rotation ranges compared with the pre-intervention values. For the NDI, pain intensity, and neck flexion, the effects sizes were large; for the majority of the other measurements, the effect sizes were small to moderate. The MT group showed significantly better results than the HE group for 2 out of 17 tests.

CONCLUSIONS

Both interventions improved function and pain after one week, with only marginal between-group differences in favor of MT.

Effects of cervical manipulation on pain, grip force control, and upper extremity muscle activity: a randomized controlled trial

Objectives

Individuals with neck pain experience disrupted grip force control when performing manipulative tasks. Manipulative physical therapy might decrease pain and change the activity of surrounding muscles; however, its effect on upper limb motor control remains undetermined. This study aims to analyze the effects of cervical manipulation on pressure pain threshold (PPT), upper extremity muscle activity along with grip force control in individuals with neck pain.

Methods

Thirty subjects with neck pain were instructed to grasp and lift an object before and after cervical (n = 15) or sham (n = 15) manipulation. The patients' PPT, electromyographic (EMG) activity of the upper extremity/scapular muscles, and grip force control were analyzed before and after one session of manipulation.

Results

No significant differences were found in the grip force control, PPT and EMG activity variables between groups.

Discussion

These results suggest that a single session of cervical manipulation may not modify upper limb motor control, more specifically grip force control and EMG activity, in patients with cervical pain. Future studies should investigate potential changes in grip force control in patients with different features of neck pain and/or by applying long-term treatment.

Level of Evidence

1b.

Repositioning error, pressure pain threshold, catastrophizing and anxiety in adolescents with chronic idiopathic neck pain

BACKGROUND

Impaired proprioception, increased pain sensitivity, higher levels of anxiety and catastrophizing are present in adults with chronic idiopathic neck pain. Despite the high prevalence of neck pain, studies in adolescents are scarce.

OBJECTIVES

The main aim was to compare pressure pain thresholds (PPTs) and joint repositioning error (JRE) between adolescents with chronic idiopathic neck pain and adolescents without neck pain. Secondary aims were to compare these groups for catastrophizing and anxiety and to investigate the association between PPTs, JRE and psychosocial variables and pain characteristics.

METHODS

80 adolescents (40 with and 40 without chronic neck pain) were assessed for: neck repositioning error, neck, upper trapezius and tibialis anterior PPTs, anxiety and catastrophizing. Neck pain was characterized in terms of intensity, frequency, duration and associated disability. MANCOVA was used for between group comparisons and Pearson and Spearman coefficients for correlational analysis.

RESULTS

Adolescents with neck pain showed higher levels of catastrophizing (p < 0.001) and anxiety (trait: p < 0.001; state: p = 0.028), lower PPTs (p < 0.001) and higher JRE (p < 0.001) than asymptomatic controls. Pain intensity, frequency and duration were moderately correlated with anxiety, and disability was moderately correlated with anxiety (r between 0.43 and 0.50, p < 0.05) and catastrophizing (r = 0.40, p < 0.05).

CONCLUSIONS

This study suggests that functional changes and maladaptive cognitive processes are present in adolescents with neck pain aged 16-18 years old. These findings need to be replicated in future studies.

Decreased spontaneous activity and altered evoked nociceptive response of rat thalamic submedius neurons to lumbar vertebra thrust

The thalamus is a central structure important to modulating and processing all mechanoreceptor input destined for the cortex. A large number of diverse mechanoreceptor endings are stimulated when a high velocity low amplitude thrust is delivered to the lumbar spine during spinal manipulation. The objective of this study was to determine if a lumbar thrust alters spontaneous and/or evoked nociceptive activity in medial thalamic submedius (Sm) neurons. Extracellular recordings were obtained from 94 thalamic Sm neurons in 54 urethane-anesthetized adult Wistar rats. Spontaneous activity was recorded 5 min before and after an L₅ control (no thrust) and thrust (85% rat body weight; 100 ms) procedure. In a subset of responsive nociceptive-specific neurons, mean changes in noxious-evoked response (10-s pinch with clip; 795 g) at three sites (tail, contra- and ipsilateral hindpaw) were determined following an L₅ thrust. Mean changes in Sm spontaneous activity (60 s bins) and evoked noxious response were compared using a mixed model repeated measures ANOVA with Bonferroni post hoc t tests and paired t tests, respectively. Compared to control, spontaneous Sm activity decreased 180-240 s following the lumbar thrust (p < 0.005). Inhibitory evoked responses were attenuated in the contralateral hindpaw following an L₅ thrust compared to control (p < 0.05). No other changes in spontaneous or noxious-evoked Sm activity were found. A delayed, but prolonged suppression of spontaneous Sm activity along with changes in noxious-evoked inhibitory responses in the contralateral hindpaw following lumbar vertebra thrust suggest that thalamic submedius neurons may play a role in central pain modulation related to manual therapy intervention.

Cervical Rotatory Manipulation Decreases Uniaxial Tensile Properties of Rabbit Atherosclerotic Internal Carotid Artery

Objective. To investigate the effects of one of the Chinese massage therapies, cervical rotatory manipulation (CRM), on uniaxial tensile properties of rabbit atherosclerotic internal carotid artery (ICA). Methods. 40 male purebred New Zealand white rabbits were randomly divided into CRM-Model group, Non-CRM-Model group, CRM-Normal group, and Non-CRM-Normal group. After modeling (atherosclerotic model) and intervention (CRM or Non-CRM), uniaxial tensile tests were performed on the ICAs to assess the differences in tensile mechanical properties between the four groups. Results. Both CRM and modeling were the main effects affecting physiological elastic modulus (PEM) of ICA. PEM in CRM-Model group was 1.81 times as much as Non-CRM-Model group, while the value in CRM-Model group was 1.34 times as much as CRM-Normal group. Maximum elastic modulus in CRM-Model group was 1.80 times as much as CRM-Normal group. Max strains in CRM-Model group and Non-CRM-Model group were 30.98% and 28.71% lower than CRM-Normal group and Non-CRM-Normal group, respectively. However, whether treated with CRM or not, the uniaxial tensile properties of healthy ICAs were not statistically different. Conclusion. CRM may decrease the uniaxial tensile properties of rabbit arteriosclerotic ICA, but with no effect on normal group. The study will aid in the meaningful explanation of the controversy about the harmfulness of CRM and the suitable population of CRM.

Effect of lumbar spinal manipulation on local and remote pressure pain threshold and pinprick sensitivity in asymptomatic individuals: a randomised trial

BACKGROUND

The mechanisms of clinical pain relief associated with spinal manipulative therapy (SMT) are poorly understood. Our objective was to determine whether lumbar high-velocity low-amplitude SMT altered pressure pain threshold (PPT) and pinprick sensitivity (PPS) locally and remotely, how long any change lasted (up to 30 min), and whether changes related to the side of SMT.

METHODS

Thirty-four asymptomatic participants (mean age 22.6 years ±4.0) received a right- or left-sided lumbar SMT. PPT and PPS were measured bilaterally at the calf, lumbar spine, scapula, and forehead before and immediately, 10, 20, and 30 min after intervention. Data were collected between October 2014 and June 2015.

RESULTS

Bilateral calf and lumbar spine PPT increased significantly after 10 - 20 min and was maintained at 30 min (7.2-11.8 % increase). PPS decreased significantly in all locations at various times (9.8 - 22.5 % decrease). At the calf and lumbar spine, PPT increased slightly more ipsilateral to the SMT than contralateral.

CONCLUSIONS

Lumbar SMT reduced deep pressure sensitivity locally and in the lower limbs for at least 30 min, whereas sensitivity to pinprick was reduced systemically. These findings suggest that SMT specifically inhibits deep pressure sensitivity distally. These findings are novel compared to other lumbar SMT studies, and may reflect a local spinal or complex supraspinal analgesic mechanism.

TRIAL REGISTRATION

Registered with the Australian New Zealand Clinical Trials Registry (ACTRN12614000682640).

Chiropractic spinal manipulative therapy for migraine: a three-armed, single-blinded, placebo, randomized controlled trial

Background and purpose

To investigate the efficacy of chiropractic spinal manipulative therapy (CSMT) for migraineurs.

Methods

This was a prospective three‐armed, single‐blinded, placebo, randomized controlled trial (RCT) of 17 months duration including 104 migraineurs with at least one migraine attack per month. The RCT was conducted at Akershus University Hospital, Oslo, Norway. Active treatment consisted of CSMT, whereas placebo was a sham push manoeuvre of the lateral edge of the scapula and/or the gluteal region. The control group continued their usual pharmacological management. The RCT consisted of a 1‐month run‐in, 3 months intervention and outcome measures at the end of the intervention and at 3, 6 and 12 months follow‐up. The primary end‐point was the number of migraine days per month, whereas secondary end‐points were migraine duration, migraine intensity and headache index, and medicine consumption.

Results

Migraine days were significantly reduced within all three groups from baseline to post‐treatment (P < 0.001). The effect continued in the CSMT and placebo group at all follow‐up time points, whereas the control group returned to baseline. The reduction in migraine days was not significantly different between the groups (P > 0.025 for interaction). Migraine duration and headache index were reduced significantly more in the CSMT than the control group towards the end of follow‐up (P = 0.02 and P = 0.04 for interaction, respectively). Adverse events were few, mild and transient. Blinding was strongly sustained throughout the RCT.

Conclusions

It is possible to conduct a manual‐therapy RCT with concealed placebo. The effect of CSMT observed in our study is probably due to a placebo response.

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.

Novel Electromyographic Protocols Using Axial Rotation and Cervical Flexion-Relaxation for the Assessment of Subjects With Neck Pain: A Feasibility Study

OBJECTIVE

The purpose of this study is to examine the feasibility of novel variations to the way cervical flexion-relaxation phenomenon (FRP) studies are conducted and the feasibility of using cervical axial rotation as an alternative objective measure of cervical pain/dysfunction.

METHODS

Electromyographic data were collected from cervical paraspinal muscles of 5 participants with neck pain and 5 asymptomatic controls. Cervical FRP was conducted as reported in the literature with the participants seated, except that they started with the head fully flexed instead of being erect. Data were also collected with participants laying prone, starting with their head hanging over the edge of the table. Additional data were collected from cervical paraspinal and sternocleidomastoid (SCM) muscles while the seated participants rotated their head fully to the right and left. Ratios were obtained for each type of test by dividing the electromyographic amplitude when muscles were most active by that when they were relaxed or in contralateral rotation.

RESULTS

In each case, the ratio was higher for the controls than for those with neck pain, suggesting that any of the 4 methods could be used to distinguish between 2 groups. The ratios were most pronounced from SCMs during axial rotation. There appeared to be a negative relationship between pain level and the ratios obtained from each method.

CONCLUSION

The findings from this small study are encouraging for all methods used, with axial rotation using SCMs appearing to be the most promising. These results indicate that larger, powered studies are warranted.

Manual and Instrument Applied Cervical Manipulation for Mechanical Neck Pain: A Randomized Controlled Trial

OBJECTIVE

The purpose of this study was to compare the effects of 2 different cervical manipulation techniques for mechanical neck pain (MNP).

METHODS

Participants with MNP of at least 1 month's duration (n = 65) were randomly allocated to 3 groups: (1) stretching (control), (2) stretching plus manually applied manipulation (MAM), and (3) stretching plus instrument-applied manipulation (IAM). MAM consisted of a single high-velocity, low-amplitude cervical chiropractic manipulation, whereas IAM involved the application of a single cervical manipulation using an (Activator IV) adjusting instrument. Preintervention and postintervention measurements were taken of all outcomes measures. Pain was the primary outcome and was measured using visual analogue scale and pressure pain thresholds. Secondary outcomes included cervical range of motion, hand grip-strength, and wrist blood pressure. Follow-up subjective pain scores were obtained via telephone text message 7 days postintervention.

RESULTS

Subjective pain scores decreased at 7-day follow-up in the MAM group compared with control (P = .015). Cervical rotation bilaterally (ipsilateral: P = .002; contralateral: P = .015) and lateral flexion on the contralateral side to manipulation (P = .001) increased following MAM. Hand grip-strength on the contralateral side to manipulation (P = .013) increased following IAM. No moderate or severe adverse events were reported. Mild adverse events were reported on 6 occasions (control, 4; MAM, 1; IAM, 1).

CONCLUSION

This study demonstrates that a single cervical manipulation is capable of producing immediate and short-term benefits for MNP. The study also demonstrates that not all manipulative techniques have the same effect and that the differences may be mediated by neurological or biomechanical factors inherent to each technique.

Chiropractic spinal manipulative therapy for cervicogenic headache: a study protocol of a single-blinded placebo-controlled randomized clinical trial

Cervicogenic headache (CEH) is a secondary headache which affects 1.0–4.6 % of the population. Although the costs are unknown, the health consequences are substantial for the individual; especially considering that they often suffers chronicity. Pharmacological management has no or only minor effect on CEH. Thus, we aim to assess the efficacy of chiropractic spinal manipulative therapy (CSMT) for CEH in a single-blinded placebo-controlled randomized clinical trial (RCT). According to the power calculations, we aim to recruit 120 participants to the RCT. Participants will be randomized into one of three groups; CSMT, placebo (sham manipulation) and control (usual non-manual management). The RCT consists of three stages: 1 month run-in, 3 months intervention and follow-up analyses at the end of intervention and 3, 6 and 12 months. Primary end-point is headache frequency, while headache duration, headache intensity, headache index (frequency × duration × intensity) and medicine consumption are secondary end-points. Primary analysis will assess a change in headache frequency from baseline to the end of intervention and to follow-up, where the groups CSMT and placebo and CSMT and control will be compared. Due to two group-comparisons, the results with p values below 0.025 will be considered statistically significant. For all secondary end-points and analyses, the significance level of 0.05 will be used. The results will be presented with the corresponding p values and 95 % confidence intervals. To our knowledge, this is the first prospective manual therapy three-armed single-blinded placebo-controlled RCT to be conducted for CEH. Current RCTs suggest efficacy in headache frequency, duration and intensity. However a firm conclusion requires clinical single-blinded placebo-controlled RCTs with few methodological shortcomings. The present study design adheres to the recommendations for pharmacological RCTs as far as possible and follows the recommended clinical trial guidelines by the International Headache Society.

Trial registration ClinicalTrials.gov identifier: NCT01687881, 2 December 2012

At Completion of a Multidisciplinary Treatment Program, Are Psychophysical Variables Associated with a VAS Improvement of 30% or More, a Minimal Clinically Important Difference, or an Absolute VAS Score Improvement of 1.5 cm or More?

OBJECTIVES

Objectives were to determine at completion of a multidisciplinary pain program: 1) what percentage of chronic low back pain (CLBP) patients had improved at 30% or more (minimal clinically important difference [MCID]) and by 1.5 cm or more (minimal important change [MIC]) on the visual analog scale (VAS) and 2) whether that improvement is associated with pain matching (PM), pain threshold (PTRE), and pain tolerance (PTOL) improvements.

METHODS

One hundred and six CLBP patients had admission and discharge scores for VAS, PM, PTRE, and PTOL. Improvement was determined by absolute, MCID, and MIC VAS improvement. Logistic regression analysis controlling for age, gender, race, education, psychoactive substance dependence, and depression was utilized to develop models for the dependent variables of improvement of overall VAS; of MCID of 50% or more; and of MIC with PM, PTOL, and PTRE as independent variables.

RESULTS

Thirty-two percent and 35% of the CLBP patients were at MCID and MIC, respectively, at discharge (68% and 65% not at MCID and MIC, respectively), and 54.7% were improved overall. Of the improved patients, 59% were at MCID and 63.7% at MIC. PM was associated with overall VAS improvement, while PTRE and PM were associated with MCID improvement. MIC and 50% or above models could not be estimated.

LIMITATIONS

The VAS was treated as a ratio scale.

CONCLUSIONS

A significant percentage of CLBP patients were at MCID and at MIC at completion of multidisciplinary treatment. PM was associated with overall VAS improvement, while PTRE and PM were associated with MCID.

The effect of manual therapy with augmentative exercises for neck pain: a randomised clinical trial

OBJECTIVES

To compare the effect of manual therapy (MT) and an augmentative exercise programme (AEP) versus MT and general neck range of motion (ROM) on functional outcomes for patients with neck pain. A secondary objective was to examine changes in self-report measures and quantitative sensory testing (QST) following MT and AEP.

METHODS

This was a randomised clinical trial. Seventy-two patients with neck pain were recruited. All patients received a single session of MT. Patients were randomly assigned to MT+AEP or MT+ROM. Clinical self-report outcome measures for disability and pain, and QST measures (pain and vibration thresholds) were collected at baseline, post MT treatment, at ∼48 hours, and at ∼96 hours. Repeated measures ANOVA and MANOVA were used to analyse within and between-group effects for clinical and QST measures.

RESULTS

There were no between-group differences for disability, pain and QST measures. There was, however, a significant difference between groups for Global Rating of Change (GRoC) scores (P = 0.037). Patients in both groups showed improvements in pain, disability and trapezius pressure-pain threshold (PPT) (all P < 0.001).

DISCUSSION

Augmentative exercise programme does not significantly improve disability, pain or QST measures in patients with chronic neck pain although it may enhance their GRoC scores. Over a 96-hour period, patients benefitted from MT plus exercise whether the exercise was general or specific.

Antinociceptive Effects of Spinal Manipulative Therapy on Nociceptive Behavior of Adult Rats during the Formalin Test

Optimizing pain relief resulting from spinal manipulative therapies, including low velocity variable amplitude spinal manipulation (LVVA-SM), requires determining their mechanisms. Pain models that incorporate simulated spinal manipulative therapy treatments are needed for these studies. The antinociceptive effects of a single LVVA-SM treatment on rat nociceptive behavior during the commonly used formalin test were investigated. Dilute formalin was injected subcutaneously into a plantar hindpaw. Licking behavior was video-recorded for 5 minutes. Ten minutes of LVVA-SM at 20° flexion was administered with a custom-made device at the lumbar (L5) vertebra of isoflurane-anesthetized experimental rats (n = 12) beginning 10 minutes after formalin injection. Hindpaw licking was video-recorded for 60 minutes beginning 5 minutes after LVVA-SM. Control rats (n = 12) underwent the same methods except for LVVA-SM. The mean times spent licking the formalin-injected hindpaw of both groups 1–5 minutes after injection were not different. The mean licking time during the first 20 minutes post-LVVA-SM of experimental rats was significantly less than that of control rats (P < 0.001). The mean licking times of both groups during the second and third 20 minutes post-LVVA-SM were not different. Administration of LVVA-SM had a short-term, remote antinociceptive effect similar to clinical findings. Therefore, mechanistic investigations using this experimental approach are warranted.

Chiropractic spinal manipulative therapy for migraine: a study protocol of a single-blinded placebo-controlled randomised clinical trial

INTRODUCTION

Migraine affects 15% of the population, and has substantial health and socioeconomic costs. Pharmacological management is first-line treatment. However, acute and/or prophylactic medicine might not be tolerated due to side effects or contraindications. Thus, we aim to assess the efficacy of chiropractic spinal manipulative therapy (CSMT) for migraineurs in a single-blinded placebo-controlled randomised clinical trial (RCT).

METHOD AND ANALYSIS

According to the power calculations, 90 participants are needed in the RCT. Participants will be randomised into one of three groups: CSMT, placebo (sham manipulation) and control (usual non-manual management). The RCT consists of three stages: 1 month run-in, 3 months intervention and follow-up analyses at the end of the intervention and 3, 6 and 12 months. The primary end point is migraine frequency, while migraine duration, migraine intensity, headache index (frequency x duration x intensity) and medicine consumption are secondary end points. Primary analysis will assess a change in migraine frequency from baseline to the end of the intervention and follow-up, where the groups CSMT and placebo and CSMT and control will be compared. Owing to two group comparisons, p values below 0.025 will be considered statistically significant. For all secondary end points and analyses, a p value below 0.05 will be used. The results will be presented with the corresponding p values and 95% CIs.

ETHICS AND DISSEMINATION

The RCT will follow the clinical trial guidelines from the International Headache Society. The Norwegian Regional Committee for Medical Research Ethics and the Norwegian Social Science Data Services have approved the project. Procedure will be conducted according to the declaration of Helsinki. The results will be published at scientific meetings and in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT01741714.

Manipulation and mobilisation for neck pain contrasted against an inactive control or another active treatment

BACKGROUND

Manipulation and mobilisation are commonly used to treat neck pain. This is an update of a Cochrane review first published in 2003, and previously updated in 2010.

OBJECTIVES

To assess the effects of manipulation or mobilisation alone compared wiith those of an inactive control or another active treatment on pain, function, disability, patient satisfaction, quality of life and global perceived effect in adults experiencing neck pain with or without radicular symptoms and cervicogenic headache (CGH) at immediate- to long-term follow-up. When appropriate, to assess the influence of treatment characteristics (i.e. technique, dosage), methodological quality, symptom duration and subtypes of neck disorder on treatment outcomes.

SEARCH METHODS

Review authors searched the following computerised databases to November 2014 to identify additional studies: the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE and the Cumulative Index to Nursing and Allied Health Literature (CINAHL). We also searched ClinicalTrials.gov, checked references, searched citations and contacted study authors to find relevant studies. We updated this search in June 2015, but these results have not yet been incorporated.

SELECTION CRITERIA

Randomised controlled trials (RCTs) undertaken to assess whether manipulation or mobilisation improves clinical outcomes for adults with acute/subacute/chronic neck pain.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies, abstracted data, assessed risk of bias and applied Grades of Recommendation, Assessment, Development and Evaluation (GRADE) methods (very low, low, moderate, high quality). We calculated pooled risk ratios (RRs) and standardised mean differences (SMDs).

MAIN RESULTS

We included 51 trials (2920 participants, 18 trials of manipulation/mobilisation versus control; 34 trials of manipulation/mobilisation versus another treatment, 1 trial had two comparisons). Cervical manipulation versus inactive control: For subacute and chronic neck pain, a single manipulation (three trials, no meta-analysis, 154 participants, ranged from very low to low quality) relieved pain at immediate- but not short-term follow-up. Cervical manipulation versus another active treatment: For acute and chronic neck pain, multiple sessions of cervical manipulation (two trials, 446 participants, ranged from moderate to high quality) produced similar changes in pain, function, quality of life (QoL), global perceived effect (GPE) and patient satisfaction when compared with multiple sessions of cervical mobilisation at immediate-, short- and intermediate-term follow-up. For acute and subacute neck pain, multiple sessions of cervical manipulation were more effective than certain medications in improving pain and function at immediate- (one trial, 182 participants, moderate quality) and long-term follow-up (one trial, 181 participants, moderate quality). These findings are consistent for function at intermediate-term follow-up (one trial, 182 participants, moderate quality). For chronic CGH, multiple sessions of cervical manipulation (two trials, 125 participants, low quality) may be more effective than massage in improving pain and function at short/intermediate-term follow-up. Multiple sessions of cervical manipulation (one trial, 65 participants, very low quality) may be favoured over transcutaneous electrical nerve stimulation (TENS) for pain reduction at short-term follow-up. For acute neck pain, multiple sessions of cervical manipulation (one trial, 20 participants, very low quality) may be more effective than thoracic manipulation in improving pain and function at short/intermediate-term follow-up. Thoracic manipulation versus inactive control: Three trials (150 participants) using a single session were assessed at immediate-, short- and intermediate-term follow-up. At short-term follow-up, manipulation improved pain in participants with acute and subacute neck pain (five trials, 346 participants, moderate quality, pooled SMD -1.26, 95% confidence interval (CI) -1.86 to -0.66) and improved function (four trials, 258 participants, moderate quality, pooled SMD -1.40, 95% CI -2.24 to -0.55) in participants with acute and chronic neck pain. A funnel plot of these data suggests publication bias. These findings were consistent at intermediate follow-up for pain/function/quality of life (one trial, 111 participants, low quality). Thoracic manipulation versus another active treatment: No studies provided sufficient data for statistical analyses. A single session of thoracic manipulation (one trial, 100 participants, moderate quality) was comparable with thoracic mobilisation for pain relief at immediate-term follow-up for chronic neck pain. Mobilisation versus inactive control: Mobilisation as a stand-alone intervention (two trials, 57 participants, ranged from very low to low quality) may not reduce pain more than an inactive control. Mobilisation versus another active treatment: For acute and subacute neck pain, anterior-posterior mobilisation (one trial, 95 participants, very low quality) may favour pain reduction over rotatory or transverse mobilisations at immediate-term follow-up. For chronic CGH with temporomandibular joint (TMJ) dysfunction, multiple sessions of TMJ manual therapy (one trial, 38 participants, very low quality) may be more effective than cervical mobilisation in improving pain/function at immediate- and intermediate-term follow-up. For subacute and chronic neck pain, cervical mobilisation alone (four trials, 165 participants, ranged from low to very low quality) may not be different from ultrasound, TENS, acupuncture and massage in improving pain, function, QoL and participant satisfaction at immediate- and intermediate-term follow-up. Additionally, combining laser with manipulation may be superior to using manipulation or laser alone (one trial, 56 participants, very low quality).

AUTHORS' CONCLUSIONS

Although support can be found for use of thoracic manipulation versus control for neck pain, function and QoL, results for cervical manipulation and mobilisation versus control are few and diverse. Publication bias cannot be ruled out. Research designed to protect against various biases is needed. Findings suggest that manipulation and mobilisation present similar results for every outcome at immediate/short/intermediate-term follow-up. Multiple cervical manipulation sessions may provide better pain relief and functional improvement than certain medications at immediate/intermediate/long-term follow-up. Since the risk of rare but serious adverse events for manipulation exists, further high-quality research focusing on mobilisation and comparing mobilisation or manipulation versus other treatment options is needed to guide clinicians in their optimal treatment choices.

Immediate and Short-Term Effects of Upper Thoracic Manipulation on Myoelectric Activity of Sternocleidomastoid Muscles in Young Women With Chronic Neck Pain: A Randomized Blind Clinical Trial

OBJECTIVE

The aim of this study was to assess the immediate and short-term effects of upper thoracic spine manipulation on pain intensity and myoelectric activity of the sternocleidomastoid muscles in young women with chronic neck pain.

METHODS

A randomized clinical trial was carried out involving 32 women with chronic neck pain (mean age, 24.8 ± 5.4 years) allocated to an experimental group and a placebo group. Three evaluations were carried out: baseline, immediate postintervention, and short-term postintervention (48-72 hours after intervention). Myoelectric activity of the right and left sternocleidomastoid muscles was assessed at rest and during isometric contractions for cervical flexion and elevation of the shoulder girdle. Neck pain intensity was assessed at rest using a visual analog scale. Comparisons of the data were performed using 2-way repeated-measures analysis of variance with the Bonferroni correction. The level of significance was set at P < .05.

RESULTS

A moderate treatment effect on myoelectric activity of the right and left sternocleidomastoid muscles during isometric elevation of the shoulder girdle was found in the experimental group only on the short-term postintervention evaluation (d > 0.40). No statistically significant differences were found for any of the variables analyzed in the intergroup comparisons at the different evaluation times (P > .05).

CONCLUSION

No statistically significant differences were found in the intragroup or intergroup analyses of the experimental and placebo groups regarding myoelectric activity of the cervical muscles or the intensity of neck pain at rest in the immediate or short-term postintervention evaluations.

The effect of spinal manipulation on deep experimental muscle pain in healthy volunteers

Background

High-velocity low-amplitude (HVLA) spinal manipulation is commonly used in the treatment of spinal pain syndromes. The mechanisms by which HVLA-manipulation might reduce spinal pain are not well understood, but often assumed to relate to the reduction of biomechanical dysfunction. It is also possible however, that HVLA-manipulation involves a segmental or generalized inhibitory effect on nociception, irrespective of biomechanical function. In the current study it was investigated whether a local analgesic effect of HVLA-manipulation on deep muscle pain could be detected, in healthy individuals.

Methods and materials

Local, para-spinal muscle pain was induced by injection of 0.5 ml sterile, hyper-tonic saline on two separate occasions 1 week apart. Immediately following the injection, treatment was administered as either a) HVLA-manipulation or b) placebo treatment, in a randomized cross-over design. Both interventions were conducted by an experienced chiropractor with minimum 6 years of clinical experience. Participants and the researcher collecting data were blinded to the treatment allocation. Pain scores following saline injection were measured by computerized visual analogue pain scale (VAS) (0-100 VAS, 1 Hz) and summarized as a) Pain duration, b) Maximum VAS, c) Time to maximum VAS and d) Summarized VAS (area under the curve). Data analysis was performed as two-way analysis of variance with treatment allocation and session number as explanatory variables.

Results

Twenty-nine healthy adults (mean age 24.5 years) participated, 13 women and 16 men. Complete data was available for 28 participants. Analysis of variance revealed no statistically significant difference between active and placebo manipulation on any of the four pain measures.

Conclusion

The current findings do not support the theory that HVLA-manipulation has a non-specific, reflex-mediated local or generalized analgesic effect on experimentally induced deep muscle pain. This in turn suggests, that any clinical analgesic effect of HVLA-manipulation is likely related to the amelioration of a pre-existing painful problem, such as reduction of biomechanical dysfunction.

Regional interdependence and manual therapy directed at the thoracic spine

Thoracic spine manipulation is commonly used by physical therapists for the management of patients with upper quarter pain syndromes. The theoretical construct for using thoracic manipulation for upper quarter conditions is a mainstay of a regional interdependence (RI) approach. The RI concept is likely much more complex and is perhaps driven by a neurophysiological response including those related to peripheral, spinal cord and supraspinal mechanisms. Recent evidence suggests that thoracic spine manipulation results in neurophysiological changes, which may lead to improved pain and outcomes in individuals with musculoskeletal disorders. The intent of this narrative review is to describe the research supporting the RI concept and its application to the treatment of individuals with neck and/or shoulder pain. Treatment utilizing both thrust and non-thrust thoracic manipulation has been shown to result in improvements in pain, range of motion and disability in patients with upper quarter conditions. Research has yet to determine optimal dosage, techniques or patient populations to which the RI approach should be applied; however, emerging evidence supporting a neurophysiological effect for thoracic spine manipulation may negate the need to fully answer this question. Certainly, there is a need for further research examining both the clinical efficacy and effectiveness of manual therapy interventions utilized in the RI model as well as the neurophysiological effects resulting from this intervention.

The comparative effects of spinal and peripheral thrust manipulation and exercise on pain sensitivity and the relation to clinical outcome: a mechanistic trial using a shoulder pain model

STUDY DESIGN

Single-blind randomized trial.

OBJECTIVES

To compare the effects of cervical and shoulder thrust manipulation (TM) and exercise on pain sensitivity, and to explore associations with clinical outcomes in patients with shoulder pain.

BACKGROUND

Experimental studies indicate that spinal TM has an influence on central pain processes, supporting its application for treatment of extremity conditions. Direct comparison of spinal and peripheral TM on pain sensitivity has not been widely examined.

METHODS

Seventy-eight participants with shoulder pain (36 female; mean ± SD age, 39.0 ± 14.5 years) were randomized to receive 3 treatments of cervical TM (n = 26), shoulder TM (n = 27), or shoulder exercise (n = 25) over 2 weeks. Twenty-five healthy participants (13 female; mean ± SD age, 35.2 ± 11.1 years) were assessed to compare pain sensitivity with that in clinical participants at baseline. Primary outcomes were changes in local (eg, shoulder) and remote (eg, tibialis anterior) pressure pain threshold and heat pain threshold occurring over 2 weeks. Secondary outcomes were shoulder pain intensity and patient-rated function at 4, 8, and 12 weeks. Analysis-of-variance models and partial-correlation analyses were conducted to examine comparative effects and the relationship between measures.

RESULTS

At baseline, clinical participants demonstrated lower local (mean difference, - 1.63 kg; 95% confidence interval [CI]: -2.40, -0.86) and remote pressure pain threshold (mean difference, -1.96 kg; 95% CI: -3.09, -0.82) and heat pain threshold (mean difference, -1.15°C; 95% CI: -2.06, -0.24) compared to controls, suggesting enhanced pain sensitivity. Following intervention, there were no between-group differences in pain sensitivity or clinical outcome (P>.05). However, improvements were noted, regardless of intervention, for pressure pain threshold (range of mean differences, 0.22-0.32 kg; 95% CI: 0.03, 0.43), heat pain threshold (range of mean differences, 0.30-0.58; 95% CI: 0.06, 0.96), pain intensity (range of mean differences, -1.79 to -1.45; 95% CI: -2.34, -0.94), and function (range of mean differences, 3.15-3.82; 95% CI: 0.69, 6.20) at all time points. We did not find an association between pain sensitivity changes and clinical outcome (P>.05). Conclusion Clinical participants showed enhanced pain sensitivity, but did not respond differently to cervical or peripheral TM. In fact, in this sample, cervical TM, shoulder TM, and shoulder exercise had similar pain sensitivity and clinical effects. The lack of association between pain sensitivity and clinical pain and function outcomes suggests different (eg, nonspecific) pain pathways for clinical benefit following TM or exercise.

LEVEL OF EVIDENCE

Therapy, level 1b.

Effect of spinal manipulation thrust magnitude on trunk mechanical activation thresholds of lateral thalamic neurons

OBJECTIVES

High-velocity low-amplitude spinal manipulation (HVLA-SM), as performed by doctors who use manual therapy (eg, doctors of chiropractic and osteopathy), results in mechanical hypoalgesia in clinical settings. This hypoalgesic effect has previously been attributed to alterations in peripheral and/or central pain processing. The objective of this study was to determine whether thrust magnitude of a simulated HVLA-SM alters mechanical trunk response thresholds in wide dynamic range (WDR) and/or nociceptive specific (NS) lateral thalamic neurons.

METHODS

Extracellular recordings were carried out in the thalamus of 15 anesthetized Wistar rats. Lateral thalamic neurons having receptive fields, which included the lumbar dorsal-lateral trunk, were characterized as either WDR (n=22) or NS (n=25). Response thresholds to electronic von Frey (rigid tip) mechanical trunk stimuli were determined in 3 directions (dorsal-ventral, 45° caudalward, and 45° cranialward) before and immediately after the dorsal-ventral delivery of a 100-millisecond HVLA-SM at 3 thrust magnitudes (control, 55%, 85% body weight).

RESULTS

There was a significant difference in mechanical threshold between 85% body weight manipulation and control thrust magnitudes in the dorsal-ventral direction in NS neurons (P=.01). No changes were found in WDR neurons at either HVLA-SM thrust magnitude.

CONCLUSIONS

This study is the first to investigate the effect of HVLA-SM thrust magnitude on WDR and NS lateral thalamic mechanical response threshold. Our data suggest that, at the single lateral thalamic neuron level, there may be a minimal spinal manipulative thrust magnitude required to elicit an increase in trunk mechanical response thresholds.