Motor-evoked potentials recorded from lumbar erector spinae muscles: a study of corticospinal excitability changes associated with spinal manipulation

Closed-loop cervical epidural stimulation partially restores ipsilesional diaphragm EMG after acute C2 hemisection

Cervical spinal cord injury creates lasting respiratory deficits which can require mechanical ventilation long-term. We have shown that closed-loop epidural stimulation (CL-ES) elicits respiratory plasticity in the form of increased phrenic network excitability (Malone et. al., E Neuro, Vol 9, 0426-21.2021, 2022); however, the ability of this treatment to create functional benefits for breathing function per se after injury has not been demonstrated. Here, we demonstrate in C2 hemisected anesthetized rats, a 20-minute bout of CL-ES administered at current amplitudes below the motor threshold restores paralyzed hemidiaphragm activity in-phase with breathing while potentiating contralesional activity. While this acute bout of stimulation did not elicit the increased network excitability seen in our chronic model, a subset of stimulated animals continued spontaneous ipsilesional diaphragm activity for several seconds after stopping stimulation. These results support the use of CL-ES as a therapeutic to rescue breathing after high cervical spinal cord injury, with the potential to lead to lasting recovery and device independence.

The Neurophysiological Lesion: A Scoping Review

Objective

The purpose of this study was to examine the extent of the literature on the neurophysiological lesion as referenced in functional neurology.

Methods

A literature search was performed within the period from 2010 to March 2021. Search terms included central sensitization, central sensitivity syndrome, nociplastic pain, cold hyperalgesia, heat hyperalgesia, mechanical hyperalgesia, dynamic mechanical allodynia, temporal summation, spatial summation, and descending inhibition. A qualitative synthesis summarized the research findings, including clinical conditions and effect of spinal manipulation.

Results

There were 30 studies, which included 7 high-level studies (meta-analysis or systematic reviews), 22 randomized controlled studies, and 1 scoping review. The findings suggest the existence of the changes in the central integrated state of a population of neurons with various disorders, experimentally induced stimulation, and treatment. The current literature suggests plasticity of the central integrative state (CIS) with the onset of pathologies and the changes in the CIS with different conservative nonpharmacologic treatments.

Conclusions

This review suggests changes in the resting state of the CIS of a population of neurons that exist in the physiologic lesion may change in response to various therapies, including manipulative therapy. The findings from this review provide support of the hypothesis that nonpharmacologic conservative care may affect the neurophysiological lesion. However, studies were heterogeneous and evidence was lacking in the translation of targeting the therapies to distinct neuronal areas for clinical outcomes to treat specific disease states.

Contribution of neural circuits tested by transcranial magnetic stimulation in corticomotor control of low back muscle: a systematic review

Introduction

Transcranial magnetic stimulation (TMS) is widely used to investigate central nervous system mechanisms underlying motor control. Despite thousands of TMS studies on neurophysiological underpinnings of corticomotor control, a large majority of studies have focused on distal muscles, and little is known about axial muscles (e.g., low back muscles). Yet, differences between corticomotor control of low back and distal muscles (e.g., gross vs. fine motor control) suggest differences in the neural circuits involved. This systematic review of the literature aims at detailing the organisation and neural circuitry underlying corticomotor control of low back muscles tested with TMS in healthy humans.

Methods

The literature search was performed in four databases (CINAHL, Embase, Medline (Ovid) and Web of science) up to May 2022. Included studies had to use TMS in combination with EMG recording of paraspinal muscles (between T12 and L5) in healthy participants. Weighted average was used to synthesise quantitative study results.

Results

Forty-four articles met the selection criteria. TMS studies of low back muscles provided consistent evidence of contralateral and ipsilateral motor evoked potentials (with longer ipsilateral latencies) as well as of short intracortical inhibition/facilitation. However, few or no studies using other paired pulse protocols were found (e.g., long intracortical inhibition, interhemispheric inhibition). In addition, no study explored the interaction between different cortical areas using dual TMS coil protocol (e.g., between primary motor cortex and supplementary motor area).

Discussion

Corticomotor control of low back muscles are distinct from hand muscles. Our main findings suggest: (i) bilateral projections from each single primary motor cortex, for which contralateral and ipsilateral tracts are probably of different nature (contra: monosynaptic; ipsi: oligo/polysynaptic) and (ii) the presence of intracortical inhibitory and excitatory circuits in M1 influencing the excitability of the contralateral corticospinal cells projecting to low back muscles. Understanding of these mechanisms are important for improving the understanding of neuromuscular function of low back muscles and to improve the management of clinical populations (e.g., low back pain, stroke).

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.

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.

The Effects of 4 Weeks of Chiropractic Spinal Adjustments on Motor Function in People with Stroke: A Randomized Controlled Trial

Chiropractic spinal adjustments have been shown to result in short-term increases in muscle strength in chronic stroke patients, however, the effect of longer-term chiropractic spinal adjustments on people with chronic stroke is unknown. This exploratory study assessed whether 4 weeks of chiropractic spinal adjustments, combined with physical therapy (chiro + PT), had a greater impact than sham chiropractic with physical therapy (sham + PT) did on motor function (Fugl Meyer Assessment, FMA) in 63 subacute or chronic stroke patients. Secondary outcomes included health-related quality of life and other measures of functional mobility and disability. Outcomes were assessed at baseline, 4 weeks (post-intervention), and 8 weeks (follow-up). Data were analyzed using linear mixed-effects models or generalized linear mixed models. A post-hoc responder analysis was performed to investigate the clinical significance of findings. At 4 weeks, there was a larger effect of chiro + PT, compared with sham + PT, on the FMA (difference = 6.1, p = 0.04). The responder analysis suggested the improvements in motor function seen following chiropractic spinal adjustments may have been clinically significant. There was also a robust improvement in both groups in most measures from baseline to the 4- and 8-week assessments, but between-group differences were no longer significant at the 8-week assessment. Four weeks of chiro + PT resulted in statistically significant improvements in motor function, compared with sham + PT, in people with subacute or chronic stroke. These improvements appear to be clinically important. Further trials, involving larger group sizes and longer follow-up and intervention periods, are required to corroborate these findings and further investigate the impacts of chiropractic spinal adjustments on motor function in post-stroke survivors. ClinicalTrials.gov Identifier NCT03849794.

Short-Term Effects of Global Pelvic Manipulation on Knee Joint Position Sense in Asymptomatic Participants: A Double-Blind Randomized Controlled Trial

OBJECTIVE

The purpose of this study was to evaluate short-term effects of the global pelvic manipulation (GPM) on knee joint position sense (JPS).

METHODS

This randomized, controlled double-blind trial included 26 asymptomatic participants (X¯± 25.3; standard deviation ± 4.4 years) who were randomly allocated into 2 groups. Sixteen participants were allocated into the experimental group, in which GPM was performed, and the rest of the participants (n = 10) were included in the control group, which received sham ultrasound therapy. Each participant attended 1 session only, and the evaluations were assessed pretreatment and 5 minutes posttreatment through an isokinetic dynamometer (Biodex Medical Systems), in which the data regarding knee JPS ipsilateral to the manipulated sacroiliac joint were collected. Mann-Whitney and Wilcoxon tests were used, with a 95% significance level.

RESULTS

There were no statistically significant differences between the groups concerning active and passive JPS at 30° and 60° (P > .05). The results showed a lack of significant differences between the moments in both groups (P > .05).

CONCLUSION

This investigation demonstrated that GPM, with high-velocity low-amplitude thrust, has no effect on knee JPS, suggesting that this manipulative technique does not have a relative effect on muscle spindles and Golgi tendon organ activation in asymptomatic participants.

The Immediate Effect of Spinal Manipulation on Ball Velocity and Neuromuscular Function During an Instep Kick in Former Varsity Soccer Players: A Feasibility Study

Corso, M, Liang, L, Tran, S, Howitt, S, Srbely, J, and Mior, SA. The immediate effect of spinal manipulation on ball velocity and neuromuscular function during an instep kick in former Varsity soccer players: a feasibility study. J Strength Cond Res XX(X): 000-000, 2020-Spinal manipulation (SM) has been shown to increase ball velocity (BV) in soccer players. Evidence suggests that SM modulates responses at spinal or cortical levels to enhance force production in asymptomatic populations. No studies have explored the underlying neuromuscular mechanisms contributing to changes in BV post-SM in soccer players. We assessed the feasibility of measuring change in BV and neuromuscular function after SM in former Varsity level soccer players with a pre-post study design. Three to 5 maximal instep kicks were performed before and after SM at the L3-5 level. Ball velocity was measured using high-speed camera. Activation of lower limb and trunk musculature was recorded with electromyography. Outcomes included ease of recruitment, scheduling and data capture, as well as expectation and perception of SM effect and adverse events (AE). Fifteen potential subjects were recruited over 1.5 months. Eleven were scheduled (24-31 years; 8 females, 3 males). Two subjects reported mild AE after maximal voluntary isometric contraction testing. A significant increase in BV (mean change: 1.75 m·s [95% confidence interval: 0.5-3.0]) and a trend to increased peak-activation of knee extensors (90.7%) were observed post-SM. Findings suggest that our recruitment strategy and methodology are feasible in a larger trial with some modifications. Our preliminary findings support previous research by suggesting that increased BV may be mediated through increased activation of knee extensors during the kick. Our findings may offer additional insight into the underlying neuromuscular mechanisms contributing to immediate change in BV post-SM.

Assessing sensorimotor control of the lumbopelvic-hip region using task-based functional MRI

Recent brain imaging studies have suggested that cortical remodeling within sensorimotor regions are associated with persistent low back pain and may be a driving mechanism for the impaired neuromuscular control associated with this condition. This paper outlines a new approach for investigating cortical sensorimotor integration during the performance of small-amplitude lumbopelvic movements with functional MRI. Fourteen healthy right-handed participants were instructed in the lumbopelvic movement tasks performed during fMRI acquisition. Surface electromyography (EMG) collected on 8 lumbopelvic and thigh muscles captured organized patterns of muscle activation during the movement tasks. fMRI data were collected on 10 of 14 participants. Sensorimotor cortical activation across the tasks was identified using a whole brain analysis and further explored with regional analyses of key components of the cortical sensorimotor network. Head motion had low correlation to the tasks (r = -0.101 to 0.004) and head translation averaged 0.98 (0.59 mm) before motion correction. Patterns of activation of the key lumbopelvic and thigh musculature (average amplitude normalized 2-17%) were significantly different across tasks (P > 0.001). Neuroimaging demonstrated activation in key sensorimotor cortical regions that were consistent with motor planning and sensory feedback needed for performing the different tasks. This approach captures the specificity of lumbopelvic sensorimotor control using goal-based tasks (e.g., "lift your hip" vs. "contract your lumbar multifidus to 20% of maximum") performed within the confines of the scanner. Specific patterns of sensorimotor cortex activation appear to capture differences between bilateral and unilateral tasks during voluntary control of multisegmental movement in the lumbopelvic region.NEW & NOTEWORTHY We demonstrated the feasibility of using task-based functional magnetic resonance imaging (fMRI) protocols for acquiring the blood oxygen level-dependent (BOLD) response of key sensorimotor cortex regions during voluntary lumbopelvic movements. Our approach activated lumbopelvic muscles during small-amplitude movements while participants were lying supine in the scanner. Our data supports these tasks can be done with limited head motion and low correlation of head motion to the task. The approach provides opportunities for assessing the role of brain changes in persistent low back pain.

The effect of a single high velocity low amplitude hip mobilization on strength in subjects with knee injuries

BACKGROUND

Manual therapy have been used as a disinhibitory intervention to increase muscle activation before performing functional tasks that are limited by weakness. Knee injuries are commonly associated with weakness in quadriceps and gluteus. Currently, there is no evidence to support anecdotal experience that a hip distraction mobilization improves muscle performance in subjects with knee injuries and lower extremity weakness.

OBJECTIVES

To determine if a hip distraction mobilization would result in an immediate change of maximal force output of the quadriceps and gluteus.

DESIGN

Non-controlled observational pre-post design.

METHODS

Forty individuals with knee pathology were included. Subjects underwent quadriceps, gluteus maximus, and gluteus medius muscle strength assessment before a single hip distraction of the symptomatic side. An immediate re-assessment of muscle strength of both symptomatic and asymptomatic sides followed the mobilization.

RESULTS

/findings: Comparing pre-to post-mobilization strength on the symptomatic side, a significant increase was found with the gluteus maximus (average change = 2.0 kg [95%CI 0.6-3.4]; p < 0.01) but not gluteus medius (0.2 kg [-0.7-1.0]; p = 0.71) or quadriceps (0.1 kg [-1.4-1.7]; p = 0.86). When comparing the strength on the symptomatic side in subjects with weakness greater than the MDD₉₅ (0.7-2.9 kg), a significant increase was again found for gluteus maximus (4.7 kg [2.6-6.8]; p < 0.01) but not for gluteus medius (0.2 kg [-1.0-1.4]; p = 0.71) or quadriceps (1.6 kg [-0.7-3.9]; p = 0.15).

CONCLUSION

A single hip distraction resulted in a significant increase in gluteus maximus strength but did not produce a change in gluteus medius or quadriceps strength in subjects with knee injuries.

Comparing targeted thrust manipulation with general thrust manipulation in patients with low back pain. A general approach is as effective as a specific one. A randomised controlled trial

Background

Spinal manipulation is commonly used to treat back pain. The application of spinal manipulation has traditionally involved an element of targeting the technique to a level of the spine where the proposed movement dysfunction is sited. We evaluated the effects of a targeted manipulative thrust versus a thrust applied generally to the lumbar region.

Methods

A randomised controlled clinical trial in patients with low back pain following CONSORT (Consolidated Standards of Reporting Trials) guidelines. Sixty subjects were randomly allocated to two groups: one group received a targeted manipulative thrust (n=29) and the other a general manipulation thrust (GT) (n=31) to the lumbar spine. Thrust was either localised to a clinician-defined symptomatic spinal level or an equal force was applied through the whole lumbosacral region. We measured pressure-pain thresholds (PPTs) using algometry and muscle activity (magnitude of stretch reflex) via surface electromyography. Numerical ratings of pain and Oswestry Disability Index scores were collected.

Results

Repeated measures of analysis of covariance revealed no between-group differences in self-reported pain or PPT for any of the muscles studied.

Summary

A GT procedure-applied without any specific targeting-was as effective in reducing participants' pain scores as targeted approaches.

Trial registration number

ISRCTN11994230.

Unravelling functional neurology: does spinal manipulation have an effect on the brain? - a systematic literature review

Background

A recent hypothesis purports that spinal manipulation may cause changes at a brain level. Functional Neurology, a mainly chiropractic approach, promotes the use of spinal manipulation to improve ‘brain function’ as if it were a proven construct. No systematic review has been performed to investigate how well founded this hypothesis is.

Objective

To investigate whether spinal manipulation has an effect on ‘brain function’ that is associated with any clinical benefits.

Method

In this systematic review, the literature was searched in PubMed, Embase, and PEDro (final search February 2018). We included randomized or non-randomized controlled studies, in which spinal manipulation was performed to any region of the spine, applied on either symptomatic or asymptomatic humans, and compared to a sham or to another type of control. The outcome measures had to be stated as direct or proxy markers of ‘brain function’. Articles were reviewed blindly by at least two reviewers, using a quality checklist designed for the specific needs of the review. Studies were classified as of ‘acceptable’, ‘medium’, or ‘low’ methodological quality. Results were reported in relation to (i) control intervention (sham, ‘inactive control’, or ‘another physical stimulus’) and (ii) study subjects (healthy, symptomatic, or with spinal pain” subjects/spinal pain”), taking into account the quality. Only results obtained from between-group or between-intervention comparisons were considered in the final analysis.

Results

Eighteen of 1514 articles were included. Studies were generally of ‘low’ or ‘medium’ methodological quality, most comparing spinal manipulation to a control other than a sham. Thirteen out of the 18 studies could be included in the final analysis. Transitory effects of different types of ‘brain function’ were reported in the three studies comparing spinal manipulation to sham (but of uncertain credibility), in “subclinical neck/spinal pain” subjects or in symptomatic subjects. None of these three studies, of ‘medium’ or ‘acceptable’ quality, investigated whether the neurophysiological effects reported were associated with clinical benefits. The remaining 10 studies, generally of ‘low’ or ‘medium’ quality, compared spinal manipulation to ‘inactive control’ or ‘another physical stimulus’ and similarly reported significant between-group differences but inconsistently.

Conclusion

The available evidence suggests that changes occur in ‘brain function’ in response to spinal manipulation but are inconsistent across and - sometimes - within studies. The clinical relevance of these changes is unknown. It is therefore premature to promote the use of spinal manipulation as a treatment to improve ‘brain function’.

Electronic supplementary material

The online version of this article (10.1186/s12998-019-0265-8) contains supplementary material, which is available to authorized users.

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.

Motor Neuron Excitability Attenuation as a Sequel to Lumbosacral Manipulation in Subacute Low Back Pain Patients and Asymptomatic Adults: A Cross-Sectional H-Reflex Study

OBJECTIVE

The purpose of the study was to compare a time series of tibial nerve H-reflex trials between patients with subacute low back pain (LBP) and asymptomatic adults using pre and post high-velocity, low-amplitude (HVLA) spinal manipulation (SM) and control procedures.

METHODS

Asymptomatic adults (n = 66) and patients with subacute LBP (n = 45) were randomized into 3 lumbosacral procedures: side-posture positioning, joint preloading with no thrust, and HVLA SM. A time series of 40 H_max/M_max ratios at a rate of 0.1 Hz were recorded in blocks of 10 trials at baseline and after the lumbosacral procedures at time points corresponding to immediately after, 5 minutes after, and 10 minutes after the procedure. Descriptive time series analysis techniques included time plots, outlier detection, and autocorrelation functions. A mixed analysis of variance model (group × procedure × time) was used to compare the effects of lumbosacral procedures on H_max/M_max ratios between the patients with subacute LBP and asymptomatic participants.

RESULTS

The time series analysis and the significant lumbosacral × time interaction term (P < .05) indicated that inhibition of the H_max/M_max ratios at the 10-second postlumbosacral procedure time point was greatest after the HVLA SM procedure. The effects of lumbosacral procedures on H_max/M_max ratios were similar between patients with subacute LBP and asymptomatic participants.

CONCLUSIONS

Although nonspecific effects of movement or position artifacts on the H_max/M_max ratio were present, a reliable and valid attenuation of the H_max/M_max ratio occurred as a specific aspect of HVLA SM in both asymptomatic adults and patients with subacute LBP.

Optimizing treatment protocols for spinal manipulative therapy: study protocol for a randomized trial

BACKGROUND

Low back pain is a common and costly condition. Spinal manipulative therapy (SMT) is a treatment supported in some guidelines, although most clinical trials examining SMT report small effect sizes. Enhancing the effects of SMT requires an understanding of underlying mechanisms and a systematic approach to leverage understanding of mechanisms to create more effective treatment protocols that are scalable in clinical practice. Prior work has identified effects on spinal stiffness and lumbar multifidus activation as possible mechanisms. This project represents a refinement phase study within the context of a multi-phase optimization strategy (MOST) framework. Our goal is to identify an optimized SMT treatment protocol by examining the impact of using co-intervention exercise strategies that are proposed to accentuate SMT mechanisms. The optimized protocol can then be evaluated in confirmation phase clinical trials and implementation studies.

METHODS

A phased, factorial randomized trial design will be used to evaluate the effects of three intervention components provided in eight combinations on mechanistic (spinal stiffness and multifidus muscle activation) and patient-reported outcomes (pain and disability). All participants will receive two sessions then will be randomly assigned to receive six additional sessions (or no additional treatment) over the next three weeks with factorial combinations of additional SMT and exercise co-interventions (spine mobilizing and multifidus activating). Outcome assessments occur at baseline, and one week, four weeks, and three months after enrollment. Pre-specified analyses will evaluate main effects for treatment components as well as interaction effects.

DISCUSSION

Building on preliminary findings identifying possible mechanisms of effects for SMT, this trial represents the next phase in a multiphase strategy towards the ultimate goal of developing an optimized protocol for providing SMT to patients with LBP. If successful, the results of this trial can be tested in future clinical trials in an effort to produce larger treatment benefits and improve patient-centered outcomes for individuals with LBP.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT02868034 . Registered on 16 August 2016.

A randomized control trial to determine the effectiveness and physiological effects of spinal manipulation and spinal mobilization compared to each other and a sham condition in patients with chronic low back pain: Study protocol for The RELIEF Study

BACKGROUND

Low back pain (LBP) is one of the most common reasons for seeking medical care. Manipulative therapies are a common treatment for LBP. Few studies have compared the effectiveness of different types of manipulative therapies. Moreover, the physiologic mechanisms underlying these treatments are not fully understood. Herein, we present the study protocol for The Researching the Effectiveness of Lumbar Interventions for Enhancing Function Study (The RELIEF Study).

METHODS AND STUDY DESIGN

The RELIEF Study is a Phase II RCT with a nested mechanistic design. It is a single-blinded, sham-controlled study to test the mechanisms and effectiveness of two manual therapy techniques applied to individuals (n = 162; 18-45 years of age) with chronic LBP. The clinical outcome data from the mechanistic component will be pooled across experiments to permit an exploratory Phase II RCT investigating the effectiveness. Participants will be randomized into one of three separate experiments that constitute the mechanistic component to determine the muscular, spinal, and cortical effects of manual therapies. Within each of these experimental groups study participants will be randomly assigned to one of the three treatment arms: 1) spinal manipulation, 2) spinal mobilization, or 3) sham laser therapy. Treatments will be delivered twice per week for 3-weeks.

DISCUSSION

This data from this will shed light on the mechanisms underlying popular treatments for LBP. Additionally, the coupling of this basic science work in the context of a clinical trial will also permit examination of the clinical efficacy of two different types of manipulative therapies.

Pragmatically Applied Cervical and Thoracic Nonthrust Manipulation Versus Thrust Manipulation for Patients With Mechanical Neck Pain: A Multicenter Randomized Clinical Trial

Study Design Randomized clinical trial. Background The comparative effectiveness between nonthrust manipulation (NTM) and thrust manipulation (TM) for mechanical neck pain has been investigated, with inconsistent results. Objective To compare the clinical effectiveness of concordant cervical and thoracic NTM and TM for patients with mechanical neck pain. Methods The Neck Disability Index (NDI) was the primary outcome. Secondary outcomes included the Patient-Specific Functional Scale (PSFS), numeric pain-rating scale (NPRS), deep cervical flexion endurance (DCF), global rating of change (GROC), number of visits, and duration of care. The covariate was clinical equipoise for intervention. Outcomes were collected at baseline, visit 2, and discharge. Patients were randomly assigned to receive either NTM or TM directed at the cervical and thoracic spines. Techniques and dosages were selected pragmatically and applied to the most symptomatic level. Two-way mixed-model analyses of covariance were used to assess clinical outcomes at 3 time points. Analyses of covariance were used to assess between-group differences for the GROC, number of visits, and duration of care at discharge. Results One hundred three patients were included in the analyses (NTM, n = 55 and TM, n = 48). The between-group analyses revealed no differences in outcomes on the NDI (P = .67), PSFS (P = .26), NPRS (P = .25), DCF (P = .98), GROC (P = .77), number of visits (P = .21), and duration of care (P = .61) for patients with mechanical neck pain who received either NTM or TM. Conclusion NTM and TM produce equivalent outcomes for patients with mechanical neck pain. The trial was registered with ClinicalTrials.gov (NCT02619500). Level of Evidence Therapy, level 1b. J Orthop Sports Phys Ther 2018;48(3):137-145. Epub 6 Feb 2018. doi:10.2519/jospt.2018.7738.

Spinal Manipulative Therapy and Sports Performance Enhancement: A Systematic Review

OBJECTIVE

The purpose of this study was to review the literature regarding the relationship between spinal manipulative therapy (SMT) and sports performance.

METHODS

PubMed and Embase databases were searched for original studies published up to July 2016. Inclusion criteria were if SMT has been applied to athletes and if any sports performance-related outcome was measured.

RESULTS

Of the 581 potential studies, 7 clinical trials were selected. Most studies had adequate quality (≥6/11) when assessed by the PEDro scale. None of those studies assessed performance at an event or competition. Four studies revealed improvement in a sports performance test after SMT. Meta-analysis could not be performed because of the wide differences in methodologies, design, and outcomes measured. Spinal manipulative therapy influences a wide range of neurophysiological parameters that could be associated with sports performance. Of the 3 studies where SMT did not improve test performance, 2 used SMT not for therapeutic correction of a dysfunctional vertebral joint but to an arbitrary previously set joint.

CONCLUSIONS

Although 4 of 7 studies showed that SMT improved sports performance tests, the evidence is still weak to support its use. Spinal manipulative therapy may be a promising approach for performance enhancement that should be investigated with more consistent methodologic designs.

Acute electromyographic responses of deep thoracic paraspinal muscles to spinal manual therapy interventions. An experimental, randomized cross-over study

This single group, randomized, cross-over study explored whether manual therapy alters motor tone of deep thoracic back muscles by examining resting electromyographic activity (EMG) after 2 types of manual therapy and a sham control intervention. Twenty-two participants with thoracic spinal pain (15 females, 7 males, mean age 28.1 ± 6.4 years) had dual fine-wire, intramuscular electrodes inserted into deep transversospinalis muscles at a thoracic level where tissues appeared abnormal to palpation (AbP) and at 2 sites above and below normal and non-tender to palpation (NT). A surface electrode was on the contralateral paraspinal mass at the level of AbP. EMG signals were recorded for resting prone, two 3-s free neck extension efforts, two 3-s resisted maximal voluntary isometric contractions (MVIC), and resting prone before the intervention. Randomized spinal manipulation, counterstrain, or sham manipulation was delivered and EMG re-measured. Participants returned 1 and 2 weeks later for the remaining 2 treatments. Reductions in resting EMG followed counterstrain in AbP (median decrease 3.3%, P = 0.01) and NT sites (median decrease 1.0%, P = 0.05) and for the surface electrode site (median decrease 2.0%, P = 0.009). Reduction in EMG following counterstrain during free neck extension was found for the surface electrode site (median decrease 2.7%, P < 0.01). Spinal manipulation produced no change in EMG, whereas counterstrain technique produced small significant reductions in paraspinal muscle activity during prone resting and free neck extension conditions. The clinical relevance of these changes is unclear.

The Effect of Velocity of Joint Mobilization on Corticospinal Excitability in Individuals With a History of Ankle Sprain

Study Design Controlled laboratory study. Background Joint mobilization and manipulation decrease pain and improve patient function. Yet, the processes underlying these changes are not well understood. Measures of corticospinal excitability provide insight into potential mechanisms mediated by the central nervous system. Objectives To investigate the differential effects of joint mobilization and manipulation at the talocrural joint on corticospinal excitability in individuals with resolved symptoms following ankle sprain. Methods Twenty-seven participants with a history of ankle sprain were randomly assigned to the control, joint mobilization, or thrust manipulation group. The motor-evoked potential (MEP) and cortical silent period (CSP) of the tibialis anterior and gastrocnemius were obtained with transcranial magnetic stimulation at rest and during active contraction of the tibialis anterior. The slopes of MEP/CSP input/output curves and the maximal MEP/CSP values were calculated to indicate corticospinal excitability. Behavioral measures, including ankle dorsiflexion and dynamic balance, were evaluated. Results A repeated-measures analysis of variance of the MEP slope showed a significant group-by-time interaction for the tibialis anterior at rest (P = .002) and during active contraction (P = .042). After intervention, the thrust manipulation group had an increase in corticospinal excitability, while the corticospinal excitability decreased in the mobilization group. The thrust manipulation group, but not other groups, also demonstrated a significant increase in the maximal MEP amplitude of the tibialis anterior after intervention. Conclusion The findings suggest that joint manipulation and mobilization have different effects on corticospinal excitability. The increased corticospinal excitability following thrust manipulation may provide a window for physical therapists to optimize muscle recruitment and subsequently movement. The trial was registered at ClinicalTrials.gov (NCT00847769). J Orthop Sports Phys Ther 2016;46(7):562-570. Epub 6 Jun 2016. doi:10.2519/jospt.2016.6602.

Motor-Evoked Potentials in the Lower Back Are Modulated by Visual Perception of Lifted Weight

Facilitation of the primary motor cortex (M1) during the mere observation of an action is highly congruent with the observed action itself. This congruency comprises several features of the executed action such as somatotopy and temporal coding. Studies using reach-grasp-lift paradigms showed that the muscle-specific facilitation of the observer’s motor system reflects the degree of grip force exerted in an observed hand action. The weight judgment of a lifted object during action observation is an easy task which is the case for hand actions as well as for lifting boxes from the ground. Here we investigated whether the cortical representation in M1 for lumbar back muscles is modulated due to the observation of a whole-body lifting movement as it was shown for hand action. We used transcranial magnetic stimulation (TMS) to measure the corticospinal excitability of the m. erector spinae (ES) while subjects visually observed the recorded sequences of a person lifting boxes of different weights from the floor. Consistent with the results regarding hand action the present study reveals a differential modulation of corticospinal excitability despite the relatively small M1 representation of the back also for lifting actions that mainly involve the lower back musculature.

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.

Paraspinal Muscle Spindle Response to Intervertebral Fixation and Segmental Thrust Level During Spinal Manipulation in an Animal Model

STUDY DESIGN

In vivo cat model study.

OBJECTIVE

To determine whether intervertebral facet joint fixation and segmental thrust level alter paraspinal muscle spindle activity during simulated spinal manipulation.

SUMMARY OF BACKGROUND DATA

Intervertebral motion is commonly assessed by manual therapy practitioners during clinical evaluation and treatment. Mechanoreceptor activity elicited during spinal manipulation has been theorized as a potential mechanism of its efficacy. The degree to which intervertebral fixation and segmental thrust level alter paraspinal muscle spindle activity during high velocity low amplitude spinal manipulation (HVLA-SM) is unclear.

METHODS

Intervertebral fixation was created by inserting facet screws through the left L(5-6) and L(6-7) and left L(4-5), L(5-6), and L(6-7) facet joints of a cat spine. Changes in the mean instantaneous frequency of L6 muscle spindle discharge were determined during 5 HVLA-SM thrust durations (0-control, 75, 100, 150, 250 ms) delivered at the L4 or L6 spinous process in each of the 3 conditions within the same preparation: laminectomy-only (surgical control; n = 23), L(5-6) and L(6-7) fixations (n = 20), and L(4-5), L(5-6), and L(6-7) fixations (n = 7). Comparisons were made between thrust levels, thrust durations, and spinal joint conditions using a linear mixed model.

RESULTS

Insertion of facet screws compared with laminectomy-only significantly increased (P < 0.001) lumbar spinal stiffness during L6 HVLA-SM. Compared with laminectomy-only, both the 2 facet screw (100 ms; P < 0.05) and 3 screw conditions [75 ms and 100 ms (P < 0.001), 150 ms (P < 0.005), and 250 ms (P < 0.05)] significantly decreased L6 spindle response during the L6 HVLA-SM. HVLA-SM-delivered 2 segments rostral to the level of muscle spindle input significantly decreases spindle response compared with HVLA-SM-delivered at-level; however, nontarget HVLA-SM still elicits 60% to 80% of at-level muscle spindle response.

CONCLUSION

Intervertebral fixation decreases paraspinal muscle spindle response during L6 HVLA-SM in a cat model. Whereas HVLA-SM target accuracy maximizes spindle response, nontarget HVLA-SM still elicits substantial levels of muscle spindle activity.

LEVEL OF EVIDENCE

N/A.

Recognising neuroplasticity in musculoskeletal rehabilitation: a basis for greater collaboration between musculoskeletal and neurological physiotherapists

Evidence is emerging for central nervous system (CNS) changes in the presence of musculoskeletal dysfunction and pain. Motor control exercises, and potentially manual therapy, can induce changes in the CNS, yet the focus in musculoskeletal physiotherapy practice is conventionally on movement impairments with less consideration of intervention-induced neuroplastic changes. Studies in healthy individuals and those with neurological dysfunction provide examples of strategies that may also be used to enhance neuroplasticity during the rehabilitation of individuals with musculoskeletal dysfunction, improving the effectiveness of interventions. In this paper, the evidence for neuroplastic changes in patients with musculoskeletal conditions is discussed. The authors compare and contrast neurological and musculoskeletal physiotherapy clinical paradigms in the context of the motor learning principles of experience-dependent plasticity: part and whole practice, repetition, task-specificity and feedback that induces an external focus of attention in the learner. It is proposed that increased collaboration between neurological and musculoskeletal physiotherapists and researchers will facilitate new discoveries on the neurophysiological mechanisms underpinning sensorimotor changes in patients with musculoskeletal dysfunction. This may lead to greater integration of strategies to enhance neuroplasticity in patients treated in musculoskeletal physiotherapy practice.

The effect of muscle energy technique on corticospinal and spinal reflex excitability in asymptomatic participants

The aim of the current study was to investigate, using a controlled, repeated measure design, the neurophysiological responses following an acute bout of muscle energy technique (MET). Transcranial magnetic stimulation elicited motor evoked potentials using a 110 mm double cone coil placed over the motor area of the brain, while Hoffman reflexes (H-reflex) were measured from the posterior tibial nerve using electrical stimulation. Responses were measured using surface electromyography electrodes placed over the lateral head of the gastrocnemius muscle in 12 asymptomatic volunteers. An MET aimed at the lumbosacral joint was performed bilaterally. Data were collected pre-intervention, after a control intervention, and after the MET intervention. A significant increase was found in evoked potential silent period (SP) duration (F2,22 = 7.64; p = 0.03) over time following MET, but not the control intervention. A significant decrease was found in H-reflex (F1.3,14.4 = 13.8; p = 0.01) over time following the MET intervention. MET applied to the lumbosacral joint produced a significant decrease in corticospinal and spinal reflex excitability, suggesting overall decreased motor excitability.

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

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

Understanding inhibitory mechanisms of lumbar spinal manipulation using H-reflex and F-wave responses: a methodological approach

The purpose of this research was to characterize unique neurophysiologic events following a high velocity, low amplitude (HVLA) spinal manipulation (SM) procedure. Descriptive time series analysis techniques of time plots, outlier detection and autocorrelation functions were applied to time series of tibial nerve H-reflexes that were evoked at 10-s intervals from 100 s before the event until 100 s after three distinct events L5-S1 HVLA SM, or a L5-S1 joint pre-loading procedure, or the control condition. Sixty-six subjects were randomly assigned to three procedures, i.e., 22 time series per group. If the detection of outliers and correlograms revealed a pattern of non-randomness that was only time-locked to a single, specific event in the normalized time series, then an experimental effect would be inferred beyond the inherent variability of H-reflex responses. Tibial nerve F-wave responses were included to determine if any new information about central nervous function following a HVLA SM procedure could be ascertained. Time series analyses of H(max)/M(max) ratios, pre-post L5-S1 HVLA SM, substantiated the hypothesis that the specific aspects of the manipulative thrust lead to a greater attenuation of the H(max)/M(max) ratio as compared to the non-specific aspects related to the postural perturbation and joint pre-loading. The attenuation of the H(max)/M(max) ratio following the HVLA SM procedure was reliable and may hold promise as a translational tool to measure the consistency and accuracy of protocol implementation involving SM in clinical trials research. F-wave responses were not sensitive to mechanical perturbations of the lumbar spine.

Transcranial magnetic stimulation as an investigative tool for motor dysfunction and recovery in stroke: an overview for neurorehabilitation clinicians

RATIONALE

An improved understanding of motor dysfunction and recovery after stroke has important clinical implications that may lead to the design of more effective rehabilitation strategies for patients with hemiparesis.

SCOPE

Transcranial magnetic stimulation (TMS) is a safe and painless tool that has been used in conjunction with other existing diagnostic tools to investigate motor pathophysiology in stroke patients. Since TMS emerged more than two decades ago, its application in clinical and basic neuroscience has expanded worldwide. TMS can quantify the corticomotor excitability properties of clinically affected and unaffected muscles and can probe local cortical networks as well as remote but functionally related areas. This provides novel insight into the physiology of neural circuits underlying motor dysfunction and brain reorganization during the motor recovery process. This important tool needs to be used with caution by clinical investigators, its limitations need to be understood, and the results should to be interpreted along with clinical evaluation in this patient population.

SUMMARY

In this review, we provide an overview of the rationale, implementation, and limitations of TMS to study stroke motor physiology. This knowledge may be useful to guide future rehabilitation treatments by assessing and promoting functional plasticity.

Basis for spinal manipulative therapy: a physical therapist perspective

Physical therapists internationally provide spinal manipulative therapy (SMT) to patients with musculoskeletal pain complaints. SMT has been a part of physical therapist practice since the profession's beginning. Early physical therapist clinical decision making for SMT was influenced by the approaches of osteopathic and orthopedic physicians at the time. Currently a segmental clinical decision making approach and a responder clinical decision making approach are two of the more common models through which physical therapist clinical use of SMT is directed. The focus of segmental clinical decision making is upon identifying a dysfunctional vertebral segment with the application of SMT to restore mobility and/or alleviate pain. The responder clinical decision making approach attempts to categorize individuals based on a pattern of signs and symptoms suggesting a likely positive response to SMT. The present manuscript provides an overview of common physical therapist clinical decision making approaches to SMT and presents areas requiring further study in order to optimize patient response.

Preliminary investigation of the mechanisms underlying the effects of manipulation: exploration of a multivariate model including spinal stiffness, multifidus recruitment, and clinical findings

STUDY DESIGN

Prospective case series.

OBJECTIVE

To examine spinal stiffness in patients with low back pain (LBP) receiving spinal manipulative therapy (SMT), evaluate associations between stiffness characteristics and clinical outcome, and explore a multivariate model of SMT mechanisms as related to effects on stiffness, lumbar multifidus (LM) recruitment, and status on a clinical prediction rule (CPR) for SMT outcomes.

SUMMARY OF BACKGROUND DATA

Mechanisms underlying the clinical effects of SMT are poorly understood. Many explanations have been proposed, but few studies have related potential mechanisms to clinical outcomes or considered multiple mechanisms concurrently.

METHODS

Patients with LBP were treated with two SMT sessions over 1 week. CPR status was assessed at baseline. Clinical outcome was based on the Oswestry disability index (ODI). Mechanized indentation measures of spinal stiffness and ultrasonic measures of LM recruitment were taken before and after each SMT, and after 1 week. Global and terminal stiffness were calculated. Multivariate regression was used to evaluate the relationship between stiffness variables and percentage ODI improvement. Zero-order correlations among stiffness variables, LM recruitment changes, CPR status, and clinical outcome were examined. A path analysis was used to evaluate a multivariate model of SMT effects.

RESULTS

Forty-eight patients (54% women) had complete stiffness data. Significant immediate decreases in global and terminal stiffness occurred post-SMT regardless of outcome. ODI improvement was related to greater immediate decrease in global stiffness (P = 0.025), and less initial terminal stiffness (P = 0.01). Zero-order correlations and path analysis supported a multivariate model suggesting that clinical outcome of SMT is mediated by improvements in LM recruitment and immediate decrease in global stiffness. Initial terminal stiffness and CPR status may relate to outcome though their relationship with LM recruitment.

CONCLUSION

The underlying mechanisms explaining the benefits of SMT appear to be multifactorial. Both spinal stiffness characteristics and LM recruitment changes appear to play a role.

Neurophysiologic effects of spinal manipulation in patients with chronic low back pain

Background

While there is growing evidence for the efficacy of SM to treat LBP, little is known on the mechanisms and physiologic effects of these treatments. Accordingly, the purpose of this study was to determine whether SM alters the amplitude of the motor evoked potential (MEP) or the short-latency stretch reflex of the erector spinae muscles, and whether these physiologic responses depend on whether SM causes an audible joint sound.

Methods

We used transcranial magnetic stimulation to elicit MEPs and electromechanical tapping to elicit short-latency stretch reflexes in 10 patients with chronic LBP and 10 asymptomatic controls. Neurophysiologic outcomes were measured before and after SM. Changes in MEP and stretch reflex amplitude were examined based on patient grouping (LBP vs. controls), and whether SM caused an audible joint sound.

Results

SM did not alter the erector spinae MEP amplitude in patients with LBP (0.80 ± 0.33 vs. 0.80 ± 0.30 μV) or in asymptomatic controls (0.56 ± 0.09 vs. 0.57 ± 0.06 μV). Similarly, SM did not alter the erector spinae stretch reflex amplitude in patients with LBP (0.66 ± 0.12 vs. 0.66 ± 0.15 μV) or in asymptomatic controls (0.60 ± 0.09 vs. 0.55 ± 0.08 μV). Interestingly, study participants exhibiting an audible response exhibited a 20% decrease in the stretch reflex (p < 0.05).

Conclusions

These findings suggest that a single SM treatment does not systematically alter corticospinal or stretch reflex excitability of the erector spinae muscles (when assessed ~ 10-minutes following SM); however, they do indicate that the stretch reflex is attenuated when SM causes an audible response. This finding provides insight into the mechanisms of SM, and suggests that SM that produces an audible response may mechanistically act to decrease the sensitivity of the muscle spindles and/or the various segmental sites of the Ia reflex pathway.

An independent review of NCCAM-funded studies of chiropractic

To promote an independent and critical evaluation of 11 randomised clinical trials (RCTs) of chiropractic funded by the National Centre for Complementary and Alternative Medicine (NCCAM). Electronic searches were conducted to identify all relevant RCTs. Key data were extracted and the risk of bias of each study was determined. Ten RCTs were included, mostly related to chiropractic spinal manipulation for musculoskeletal problems. Their quality was frequently questionable. Several RCTs failed to report adverse effects and the majority was not described in sufficient detail to allow replication. The criticism repeatedly aimed at NCCAM seems justified, as far as their RCTs of chiropractic is concerned. It seems questionable whether such research is worthwhile.

Novel methods for quantifying neurophysiologic properties of the human lumbar paraspinal muscles

Our understanding the neurophysiologic characteristics of the human paraspinal muscles has historically been hindered by the lack of experimental techniques to examine these muscles function in vivo. In this article we describe a paired-pulse transcranial magnetic stimulation (TMS) protocol to quantify intracortical facilitation (ICF) and short-interval intracortical inhibition (SICI) of the lumbar paraspinal muscles, and an electromechanical tapping protocol to measure the amplitude of the short-latency stretch reflex. Test-retest reliability of these protocols was examined across two sessions separated by 30-min in healthy adults. We assessed relative reliability by calculating the intraclass correlation coefficient (ICC), and absolute reliability was assessed via coefficient of variation (CV). ICF and SICI in the lumbar paraspinal muscles exhibited the classical facilitatory and inhibitory responses observed in appendicular skeletal muscles (∼30% facilitation and inhibition, respectively). The motor evoked potential amplitude (MEP), ICF, SICI, and stretch reflex amplitude measurements did not significantly differ between the two testing sessions (p>0.05). The MEP amplitude, ICF and stretch reflex amplitude exhibited the highest relative and absolute reliability (ICC=0.89-0.91, CV=10.6-11.1%); whereas the SICI measure exhibited somewhat lower reliability (ICC=0.75, CV=20.1%). The stretch reflex protocol performed in the first testing session did not influence the TMS outcome measures in the second testing session (p>0.05). These innovative methods may be useful in studying basic physiology, the pathology of low back pain, as well as the mechanisms of action of treatment interventions.

Comparison of the effectiveness of three manual physical therapy techniques in a subgroup of patients with low back pain who satisfy a clinical prediction rule: a randomized clinical trial

STUDY DESIGN

Randomized clinical trial.

OBJECTIVE

The purpose of this randomized clinical trial was to examine the generalizability of 3 different manual therapy techniques in a patient population with low back pain that satisfy a clinical prediction rule (CPR).

SUMMARY OF BACKGROUND DATA

Recently a CPR that identifies patients with LBP who are likely to respond rapidly and dramatically to thrust manipulation has been developed and validated. The generalizability of the CPR requires further investigation.

METHODS

A total of 112 patients were enrolled in the trial and provided demographic information and completed a number of self-report questionnaires including the Oswestry Disability Questionnaire (ODQ) and the Numerical Pain Rating Scale (NPRS) at baseline, 1-week, 4-weeks, and 6-months. Patients were randomly assigned to receive 1 of the 3 manual therapy techniques for 2 consecutive treatment sessions followed by exercise regimen for an additional 3 sessions. We examined the primary aim using a linear mixed model for repeated measures, using the ODQ and NPRS as dependent variables. The hypothesis of interest was the group by time interaction, which was further explored with pair-wise comparisons of the estimated marginal means.

RESULTS

There was a significant group x time interaction for the ODQ (P < 0.001) and NPRS scores (P = 0.001). Pair-wise comparisons revealed no differences between the supine thrust manipulation and side-lying thrust manipulation at any follow-up period. Significant differences in the ODQ and NPRS existed at each follow-up between the thrust manipulation and the nonthrust manipulation groups at 1-week and 4-weeks. There was also a significant difference in ODQ scores at 6-months in favor of the thrust groups.

CONCLUSION

The results of the study support the generalizability of the CPR to another thrust manipulation technique, but not to the nonthrust manipulation technique that was used in this study. In general, our results also provided support that the CPR can be generalized to different settings from which it was derived and validated. However, additional research is needed to examine this issue.

Identification of potential neuromotor mechanisms of manual therapy in patients with musculoskeletal disablement: rationale and description of a clinical trial

Background

Many health care practitioners use a variety of hands-on treatments to improve symptoms and disablement in patients with musculoskeletal pathology.

Research to date indirectly suggests a potentially broad effect of manual therapy on the neuromotor processing of functional behavior within the supraspinal central nervous system (CNS) in a manner that may be independent of modification at the level of local spinal circuits. However, the effect of treatment speed, as well as the specific mechanism and locus of CNS changes, remain unclear.

Methods/Design

We developed a placebo-controlled, randomized study to test the hypothesis that manual therapy procedures directed to the talocrural joint in individuals with post-acute ankle sprain induce a change in corticospinal excitability that is relevant to improve the performance of lower extremity functional behavior.

Discussion

This study is designed to identify potential neuromotor changes associated with manual therapy procedures directed to the appendicular skeleton, compare the relative effect of treatment speed on potential neuromotor effects of manual therapy procedures, and determine the behavioral relevance of potential neuromotor effects of manual therapy procedures.

Trial Registration

identifier NCT00847769.

Common errors and clinical guidelines for manual muscle testing: "the arm test" and other inaccurate procedures

BACKGROUND

The manual muscle test (MMT) has been offered as a chiropractic assessment tool that may help diagnose neuromusculoskeletal dysfunction. We contend that due to the number of manipulative practitioners using this test as part of the assessment of patients, clinical guidelines for the MMT are required to heighten the accuracy in the use of this tool.

OBJECTIVE

To present essential operational definitions of the MMT for chiropractors and other clinicians that should improve the reliability of the MMT as a diagnostic test. Controversy about the usefulness and reliability of the MMT for chiropractic diagnosis is ongoing, and clinical guidelines about the MMT are needed to resolve confusion regarding the MMT as used in clinical practice as well as the evaluation of experimental evidence concerning its use.

DISCUSSION

We expect that the resistance to accept the MMT as a reliable and valid diagnostic tool will continue within some portions of the manipulative professions if clinical guidelines for the use of MMT methods are not established and accepted. Unreliable assessments of this method of diagnosis will continue when non-standard MMT research papers are considered representative of the methods used by properly trained clinicians.

CONCLUSION

Practitioners who employ the MMT should use these clinical guidelines for improving their use of the MMT in their assessments of muscle dysfunction in patients with musculoskeletal pain.