Benefits and harms of spinal manipulative therapy for the treatment of chronic low back pain: systematic review and meta-analysis of randomised controlled trials

Swait G., Finch R.

Communicating to patients the risks of manual treatment to the spine is an important, but challenging element of informed consent. This scoping review aimed to characterise and summarise the available literature on risks and to describe implications for clinical practice and research. A methodological framework for scoping reviews was followed. Systematic searches were conducted during June 2017. The quantity, nature and sources of literature were described. Findings of included studies were narratively summarised, highlighting key clinical points. Two hundred and fifty articles were included. Cases of serious adverse events were reported. Observational studies, randomised studies and systematic reviews were also identified, reporting both benign and serious adverse events. Benign adverse events were reported to occur commonly in adults and children. Predictive factors for risk are unclear, but for neck pain patients might include higher levels of neck disability or cervical manipulation. In neck pain patients benign adverse events may result in poorer short term, but not long term outcomes. Serious adverse event incidence estimates ranged from 1 per 2 million manipulations to 13 per 10,000 patients. Cases are reported in adults and children, including spinal or neurological problems as well as cervical arterial strokes. Case-control studies indicate some association, in the under 45 years age group, between manual interventions and cervical arterial stroke, however it is unclear whether this is causal. Elderly patients have no greater risk of traumatic injury compared with visiting a medical practitioner for neuro-musculoskeletal problems, however some underlying conditions may increase risk. Existing literature indicates that benign adverse events following manual treatments to the spine are common, while serious adverse events are rare. The incidence and causal relationships with serious adverse events are challenging to establish, with gaps in the literature and inherent methodological limitations of studies. Clinicians should ensure that patients are informed of risks during the consent process. Since serious adverse events could result from pre-existing pathologies, assessment for signs or symptoms of these is important. Clinicians may also contribute to furthering understanding by utilising patient safety incident reporting and learning systems where adverse events have occurred.

Savović J., Turner R.M., Mawdsley D., Jones H.E., Beynon R., Higgins J.P., Sterne J.A.

Flaws in the design of randomized trials may bias intervention effect estimates and increase between-trial heterogeneity. Empirical evidence suggests that these problems are greatest for subjectively assessed outcomes. For the Risk of Bias in Evidence Synthesis (ROBES) Study, we extracted risk-of-bias judgements (for sequence generation, allocation concealment, blinding, and incomplete data) from a large collection of meta-analyses published in the Cochrane Library (issue 4; April 2011). We categorized outcome measures as mortality, other objective outcome, or subjective outcome, and we estimated associations of bias judgements with intervention effect estimates using Bayesian hierarchical models. Among 2,443 randomized trials in 228 meta-analyses, intervention effect estimates were, on average, exaggerated in trials with high or unclear (versus low) risk-of-bias judgements for sequence generation (ratio of odds ratios (ROR) = 0.91, 95% credible interval (CrI): 0.86, 0.98), allocation concealment (ROR = 0.92, 95% CrI: 0.86, 0.98), and blinding (ROR = 0.87, 95% CrI: 0.80, 0.93). In contrast to previous work, we did not observe consistently different bias for subjective outcomes compared with mortality. However, we found an increase in between-trial heterogeneity associated with lack of blinding in meta-analyses with subjective outcomes. Inconsistency in criteria for risk-of-bias judgements applied by individual reviewers is a likely limitation of routinely collected bias assessments. Inadequate randomization and lack of blinding may lead to exaggeration of intervention effect estimates in randomized trials.

Ulger O., Demirel A., Oz M., Tamer S.

To determine the effects of spinal stabilization exercises (SSE) and manual therapy methods on pain, function and quality of life (QoL) levels in individuals with chronic low back pain (CLBP).A total of one-hundred thirteen patients diagnosed as CLBP were enrolled to the study. The patients allocated into Spinal Stabilization group (SG) and manual therapy group (MG), randomly. While SSE performed in SG, soft tissue mobilizations, muscle-energy techniques, joint mobilizations and manipulations were performed in MG. While the severity of pain was assessed with Visual Analog Scale (VAS), Oswestry Disability Index (ODI) and Short Form 36 (SF-36) assessments were performed to evaluate the functional status and QoL, respectively. All assessments were repeated before and after the treatment.Intragroup analyses both treatments were effective in terms of sub parameters of pain, function and life quality (p< 0.05). Inter group analyses, there was more reduction in pain and improvement in functional status in favor of MG (p< 0.05).This study showed that SSE and manual therapy methods have the same effects on QoL, while the manual treatment is more effective on the pain and functional parameters in particular.

Vos T., Abajobir A.A., Abate K.H., Abbafati C., Abbas K.M., Abd-Allah F., Abdulkader R.S., Abdulle A.M., Abebo T.A., Abera S.F., Aboyans V., Abu-Raddad L.J., Ackerman I.N., Adamu A.A., Adetokunboh O., et. al.

Summary Background As mortality rates decline, life expectancy increases, and populations age, non-fatal outcomes of diseases and injuries are becoming a larger component of the global burden of disease. The Global Burden of Diseases, Injuries, and Risk Factors Study 2016 (GBD 2016) provides a comprehensive assessment of prevalence, incidence, and years lived with disability (YLDs) for 328 causes in 195 countries and territories from 1990 to 2016. Methods We estimated prevalence and incidence for 328 diseases and injuries and 2982 sequelae, their non-fatal consequences. We used DisMod-MR 2.1, a Bayesian meta-regression tool, as the main method of estimation, ensuring consistency between incidence, prevalence, remission, and cause of death rates for each condition. For some causes, we used alternative modelling strategies if incidence or prevalence needed to be derived from other data. YLDs were estimated as the product of prevalence and a disability weight for all mutually exclusive sequelae, corrected for comorbidity and aggregated to cause level. We updated the Socio-demographic Index (SDI), a summary indicator of income per capita, years of schooling, and total fertility rate. GBD 2016 complies with the Guidelines for Accurate and Transparent Health Estimates Reporting (GATHER). Findings Globally, low back pain, migraine, age-related and other hearing loss, iron-deficiency anaemia, and major depressive disorder were the five leading causes of YLDs in 2016, contributing 57·6 million (95% uncertainty interval [UI] 40·8–75·9 million [7·2%, 6·0–8·3]), 45·1 million (29·0–62·8 million [5·6%, 4·0–7·2]), 36·3 million (25·3–50·9 million [4·5%, 3·8–5·3]), 34·7 million (23·0–49·6 million [4·3%, 3·5–5·2]), and 34·1 million (23·5–46·0 million [4·2%, 3·2–5·3]) of total YLDs, respectively. Age-standardised rates of YLDs for all causes combined decreased between 1990 and 2016 by 2·7% (95% UI 2·3–3·1). Despite mostly stagnant age-standardised rates, the absolute number of YLDs from non-communicable diseases has been growing rapidly across all SDI quintiles, partly because of population growth, but also the ageing of populations. The largest absolute increases in total numbers of YLDs globally were between the ages of 40 and 69 years. Age-standardised YLD rates for all conditions combined were 10·4% (95% UI 9·0–11·8) higher in women than in men. Iron-deficiency anaemia, migraine, Alzheimer's disease and other dementias, major depressive disorder, anxiety, and all musculoskeletal disorders apart from gout were the main conditions contributing to higher YLD rates in women. Men had higher age-standardised rates of substance use disorders, diabetes, cardiovascular diseases, cancers, and all injuries apart from sexual violence. Globally, we noted much less geographical variation in disability than has been documented for premature mortality. In 2016, there was a less than two times difference in age-standardised YLD rates for all causes between the location with the lowest rate (China, 9201 YLDs per 100 000, 95% UI 6862–11943) and highest rate (Yemen, 14 774 YLDs per 100 000, 11 018–19 228). Interpretation The decrease in death rates since 1990 for most causes has not been matched by a similar decline in age-standardised YLD rates. For many large causes, YLD rates have either been stagnant or have increased for some causes, such as diabetes. As populations are ageing, and the prevalence of disabling disease generally increases steeply with age, health systems will face increasing demand for services that are generally costlier than the interventions that have led to declines in mortality in childhood or for the major causes of mortality in adults. Up-to-date information about the trends of disease and how this varies between countries is essential to plan for an adequate health-system response. Funding Bill & Melinda Gates Foundation, and the National Institute on Aging and the National Institute of Mental Health of the National Institutes of Health.

Fryer G.

This article reviews and discusses the biological and psychological mechanisms that may be responsible for therapeutic effect in an osteopathic therapeutic encounter. Although many of the reviewed mechanisms require additional high-quality evidence, osteopathic treatment may reduce pain and improve movement and function from a ‘bottom-up' influence on tissues and tissue receptors and from a ‘top-down' influence on cognitive and psychological states. Osteopathic models and manipulative technique have traditionally emphasized tissue and biomechanical mechanisms, but this emphasis is misplaced given the paucity of clinical evidence for these effects. In recent decades, growing evidence supports the importance of neurological and psychosocial factors in musculoskeletal pain, making the ‘biopsychosocial' model of pain management a mainstream consideration for the management of pain. This article proposes that both biological and psychosocial therapeutic mechanisms may contribute to therapeutic effect and that tissue and neurological effects on pain and motion, albeit small and temporary, may complement cognitive reassurance and education to promote improved confidence and control in movement. Judgement of the dominating factors will help determine the clinical approach. Part 2 will explore the clinical approaches that arise from an understanding of the mechanisms likely involved in manual therapy.

Xia T., Long C.R., Vining R.D., Gudavalli M.R., DeVocht J.W., Kawchuk G.N., Wilder D.G., Goertz C.M.

Spinal manipulation (SM) is used commonly for treating low back pain (LBP). Spinal stiffness is routinely assessed by clinicians performing SM. Flexion-relaxation ratio (FRR) was shown to distinguish between LBP and healthy populations. The primary objective of this study was to examine the association of these two physiological variables with patient-reported pain intensity and disability in adults with chronic LBP (>12 weeks) receiving SM. A single-arm trial provided 12 sessions of side-lying thrust SM in the lumbosacral region over 6 weeks. Inclusion criteria included 21–65 years old, Roland-Morris Disability Questionnaire (RMDQ) score ≥ 6 and numerical pain rating score ≥ 2. Spinal stiffness and FRR were assessed pre-treatment at baseline, after 2 weeks and after 6 weeks of treatment. Lumbar spine global stiffness (GS) were calculated from the force-displacement curves obtained using i) hand palpation, ii) a hand-held device, and iii) an automated indenter device. Lumbar FRR was assessed during trunk flexion-extension using surface electromyography. The primary outcomes were RMDQ and pain intensity measured by visual analog scale (VAS). Mixed-effects regression models were used to analyze the data. The mean age of the 82 participants was 45 years; 48% were female; and 84% reported LBP >1 year. The mean (standard deviation) baseline pain intensity and RMDQ were 46.1 (18.1) and 9.5 (4.3), respectively. The mean reduction (95% confidence interval) after 6 weeks in pain intensity and RMDQ were 20.1 mm (14.1 to 26.1) and 4.8 (3.7 to 5.8). There was a small change over time in the palpatory GS but not in the hand-held or automated GS, nor in FRR. The addition of each physiologic variable did not affect the model-estimated changes in VAS or RMDQ over time. There was no association seen between physiological variables and LBP intensity. Higher levels of hand-held GS at L3 and automated GS were significantly associated with higher levels of RMDQ (p = 0.02 and 0.03, respectively) and lower levels of flexion and extension FRR were significantly associated with higher levels of RMDQ (p = 0.02 and 0.008, respectively) across the 3 assessment time points. Improvement in pain and disability observed in study participants with chronic LBP was not associated with the measured GS or FRR. NCT01670292 on clinicaltrials.gov, August 2, 2012

Randoll C., Gagnon-Normandin V., Tessier J., Bois S., Rustamov N., O'Shaughnessy J., Descarreaux M., Piché M.

The aim of the present study was to determine whether thoracic spinal manipulation (SM) decreases temporal summation of back pain. The study comprised two controlled experiments including 16 and 15 healthy participants, respectively. Each study included six sessions during which painful or non-painful electrical stimulations were delivered in three conditions: (1) control (2) light mechanical stimulus (MS) or (3) SM. Electrical stimulation was applied on the thoracic spine (T4), in the area where SM and MS were performed. In Experiment 1, electrical stimulation consisted in a single 1-ms pulse while a single or repeated train of ten 1-ms pulses was used in Experiment 2. SM involved articular cavitation while MS was a calibrated force of 25N applied manually for 2s. For the single pulse, changes in pain or tactile sensation in the SM or MS sessions compared with the CTL session were not significantly different (all p's>0.05). In contrast, temporal summation of pain was decreased in the SM session compared with the CTL session for both the single and repeated train (p's0.1). These results indicate that SM produces specific inhibitory effects on temporal summation of back pain, consistent with the involvement of a spinal anti-nociceptive mechanism in clinical pain relief by SM. This provides the first mechanistic evidence of back pain relief by spinal manipulation.

Stochkendahl M.J., Kjaer P., Hartvigsen J., Kongsted A., Aaboe J., Andersen M., Andersen M.Ø., Fournier G., Højgaard B., Jensen M.B., Jensen L.D., Karbo T., Kirkeskov L., Melbye M., Morsel-Carlsen L., et. al.

To summarise recommendations about 20 non-surgical interventions for recent onset (<12 weeks) non-specific low back pain (LBP) and lumbar radiculopathy (LR) based on two guidelines from the Danish Health Authority. Two multidisciplinary working groups formulated recommendations based on the GRADE approach. Sixteen recommendations were based on evidence, and four on consensus. Management of LBP and LR should include information about prognosis, warning signs, and advise to remain active. If treatment is needed, the guidelines suggest using patient education, different types of supervised exercise, and manual therapy. The guidelines recommend against acupuncture, routine use of imaging, targeted treatment, extraforaminal glucocorticoid injection, paracetamol, NSAIDs, and opioids. Recommendations are based on low to moderate quality evidence or on consensus, but are well aligned with recommendations from international guidelines. The guideline working groups recommend that research efforts in relation to all aspects of management of LBP and LR be intensified.

Qaseem A., Wilt T.J., McLean R.M., Forciea M.A.

Description The American College of Physicians (ACP) developed this guideline to present the evidence and provide clinical recommendations on noninvasive treatment of low back pain. Methods Using the ACP grading system, the committee based these recommendations on a systematic review of randomized, controlled trials and systematic reviews published through April 2015 on noninvasive pharmacologic and nonpharmacologic treatments for low back pain. Updated searches were performed through November 2016. Clinical outcomes evaluated included reduction or elimination of low back pain, improvement in back-specific and overall function, improvement in health-related quality of life, reduction in work disability and return to work, global improvement, number of back pain episodes or time between episodes, patient satisfaction, and adverse effects. Target Audience and Patient Population The target audience for this guideline includes all clinicians, and the target patient population includes adults with acute, subacute, or chronic low back pain. Recommendation 1 Given that most patients with acute or subacute low back pain improve over time regardless of treatment, clinicians and patients should select nonpharmacologic treatment with superficial heat (moderate-quality evidence), massage, acupuncture, or spinal manipulation (low-quality evidence). If pharmacologic treatment is desired, clinicians and patients should select nonsteroidal anti-inflammatory drugs or skeletal muscle relaxants (moderate-quality evidence). (Grade: strong recommendation). Recommendation 2 For patients with chronic low back pain, clinicians and patients should initially select nonpharmacologic treatment with exercise, multidisciplinary rehabilitation, acupuncture, mindfulness-based stress reduction (moderate-quality evidence), tai chi, yoga, motor control exercise, progressive relaxation, electromyography biofeedback, low-level laser therapy, operant therapy, cognitive behavioral therapy, or spinal manipulation (low-quality evidence). (Grade: strong recommendation). Recommendation 3 In patients with chronic low back pain who have had an inadequate response to nonpharmacologic therapy, clinicians and patients should consider pharmacologic treatment with nonsteroidal anti-inflammatory drugs as first-line therapy, or tramadol or duloxetine as second-line therapy. Clinicians should only consider opioids as an option in patients who have failed the aforementioned treatments and only if the potential benefits outweigh the risks for individual patients and after a discussion of known risks and realistic benefits with patients. (Grade: weak recommendation, moderate-quality evidence).

Dorron S.L., Losco B.E., Drummond P.D., Walker B.F.

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

Ruddock J.K., Sallis H., Ness A., Perry R.E.

The purpose of this systematic review was to identify and critically evaluate randomized controlled trials of spinal manipulation (SM) vs sham manipulation in the treatment of nonspecific low back pain.Four electronic databases were searched from their inception to March 2015 to identify all relevant trials. Reference lists of retrieved articles were hand-searched. All data were extracted by 2 independent reviewers, and risk of bias was assessed using the Cochrane Back Review Group Risk of Bias tool.Nine randomized controlled trials were included in the systematic review, and 4 were found to be eligible for inclusion in a meta-analysis. Participants in the SM group had improved symptoms compared with participants receiving sham treatment (standardized mean difference = - 0.36; 95% confidence interval, - 0.59 to - 0.12). The majority of studies were of low risk of bias; however, several of the studies were small, the practitioner could not be blinded, and some studies did not conduct intention-to-treat analysis and had a high level of dropouts.There is some evidence that SM has specific treatment effects and is more effective at reducing nonspecific low back pain when compared with an effective sham intervention. However, given the small number of studies included in this analysis, we should be cautious of making strong inferences based on these results.

Andronis L., Kinghorn P., Qiao S., Whitehurst D.G., Durrell S., McLeod H.

Low back pain (LBP) is a major health problem, having a substantial effect on peoples’ quality of life and placing a significant economic burden on healthcare systems and, more broadly, societies. Many interventions to alleviate LBP are available but their cost effectiveness is unclear. To identify, document and appraise studies reporting on the cost effectiveness of non-invasive and non-pharmacological treatment options for LBP. Relevant studies were identified through systematic searches in bibliographic databases (EMBASE, MEDLINE, PsycINFO, Cochrane Library, CINAHL and the National Health Service Economic Evaluation Database), ‘similar article’ searches and reference list scanning. Study selection was carried out by three assessors, independently. Study quality was assessed using the Consensus on Health Economic Criteria checklist. Data were extracted using customized extraction forms. Thirty-three studies were identified. Study interventions were categorised as: (1) combined physical exercise and psychological therapy, (2) physical exercise therapy only, (3) information and education, and (4) manual therapy. Interventions assessed within each category varied in terms of their components and delivery. In general, combined physical and psychological treatments, information and education interventions, and manual therapies appeared to be cost effective when compared with the study-specific comparators. There is inconsistent evidence around the cost effectiveness of physical exercise programmes as a whole, with yoga, but not group exercise, being cost effective. The identified evidence suggests that combined physical and psychological treatments, medical yoga, information and education programmes, spinal manipulation and acupuncture are likely to be cost-effective options for LBP.

Krekoukias G., Gelalis I.D., Xenakis T., Gioftsos G., Dimitriadis Z., Sakellari V.

The aim of the study was to examine the efficacy of spinal mobilization in subjects with low back pain (LBP) and associated spinal disk degeneration.Seventy-five subjects suffering from chronic LBP (>3 months) were randomly allocated into 3 groups of 25 subjects each. Each group received five treatment sessions with the first group receiving manual therapy (MT) (spinal mobilization), the second a sham treatment, and the third conventional physiotherapy (CP) (stretching exercises, transcutaneous electrical nerve stimulation, and massage). Subjects were assessed for their pain intensity using the numerical pain rating scale and for their self-reported disability using the Oswestry and Roland-Morris Questionnaire at baseline and after the completion of the five treatment sessions.Paired t-tests showed a significant improvement for all outcome measures in the MT and CP group (p < 0.05). Analysis of covariance revealed that the MT group had significant improvement in all outcome measures in comparison with the sham and CP group (p < 0.05), whereas no significant difference was observed between the sham and CP group (p > 0.05).MT is preferable to CP in order to reduce the pain intensity and disability in subjects with chronic LBP and associated disk degeneration. The findings of this study may lead to the establishment of spinal mobilization as one of the most preferable approaches for the management of LBP due to disk degeneration.1b.

Currie S.J., Myers C.A., Durso C., Enebo B.A., Davidson B.S.

The purpose of this study was to evaluate differences in muscle activity in participants with and without low back pain during a side-lying lumbar diversified spinal manipulation.Surface and indwelling electromyography at eight muscle locations were recorded during lumbar side-lying manipulations in 20 asymptomatic participants and 20 participants with low back pain. The number of muscle responses and muscle activity onset delays in relation to the manipulation impulse were compared in the 2 pain groups using mixed linear regressions. Effect sizes for all comparisons were calculated using Cohen's d.Muscle responses occurred in 61.6% ± 23.6% of the EMG locations in the asymptomatic group and 52.8% ± 26.3% of the symptomatic group. The difference was not statistically significant but there was a small effect of pain (d = 0.350). Muscle activity onset delays were longer for the symptomatic group at every EMG location except the right side indwelling L5 electrode, and a small effect of pain was present at the left L2, quadratus lumborum and trapezius surface electrodes (d = 0.311, 0.278, and 0.265) respectively. The indwelling electrodes demonstrated greater muscle responses (P ≤ .01) and shorter muscle activity onset delays (P < .01) than the surface electrodes.The results revealed trends that indicate participants with low back pain have less muscle responses, and when muscle responses are present they occur with longer onset delays following the onset of a manipulation impulse.

Castro-Sánchez A.M., Lara-Palomo I.C., Matarán-Peñarrocha G.A., Fernández-de-las-Peñas C., Saavedra-Hernández M., Cleland J., Aguilar-Ferrándiz M.E.

Chronic low back pain (LBP) is a prevalent condition associated with pain, disability, decreased quality of life, and fear of movement. To date, no studies have compared the effectiveness of spinal manipulation and functional technique for the management of this population.This study aimed to compare the effectiveness of spinal manipulation and functional technique on pain, disability, kinesiophobia, and quality of life in patients with chronic LBP.A single-blind pragmatic randomized controlled trial conducted in a university research clinic was carried out.Sixty-two patients (62% female, age: 45±7) with chronic LBP comprised the patient sample.Data on disability (Roland-Morris Disability Questionnaire [RMQ], Oswestry Low Back Pain Disability Index [ODI]), pain intensity (Numerical Pain Rate Scale [NPRS]), fear of movement (Tampa Scale of Kinesiophobia [TSK]), quality of life (Short Form-36 [SF-36] quality of life questionnaire), isometric resistance of abdominal muscles (McQuade test), and spinal mobility in flexion (finger-to-floor distance) were collected at baseline immediately after the intervention phase and at 1 month postintervention by an assessor blinded to group allocation of the patients.Patients were randomly assigned to the spinal manipulative therapy group or the functional technique group and received three once-weekly sessions.In comparison to patients receiving functional technique, those receiving spinal manipulation experienced statistically, although not clinically, significant greater reductions in terms of RMQ (standardized mean difference in score changes between groups at post-treatment: 0.1; at 1 month: 0.1) and ODI (post-treatment: 2.9; at 1 month: 1.4). Linear longitudinal analysis showed a significant improvement in both groups over time for RMQ (manipulative: F=68.51, p

Monteiro E.R., de Oliveira Muniz Cunha J.C., de Souza Horsth T., de Araujo Barros I., de Souza R.C., de Andrade W.C., Corrêa Neto V.G., de Sá Ferreira A., de Jesus I.R.

Narenthiran P., Granville Smith I., Williams F.M.

Keter D.L., Bialosky J.E., Brochetti K., Courtney C.A., Funabashi M., Karas S., Learman K., Cook C.E.

Introduction Treatment mechanisms are the underlying process or pathway through which a treatment influences the body. This includes molecular, cellular and physiological processes or pathways contributing to treatment effect. Manual therapy (MT) evokes complex mechanistic responses across body systems, interacting with the individual patient and context to promote a treatment response. Challenges arise as mechanistic studies are spread across multiple professions, settings and populations. The purpose of this review is to summarize treatment mechanisms that have been reported to occur with MT application. Methods Four electronic databases were searched (Medline, CINAHL, Cochrane Library, and PEDro) for reviews investigating mechanistic responses which occur during/post application of MT. This review was registered a priori with PROSPERO (CRD42023444839). Methodological quality (AMSTAR-2) and risk of bias (ROBIS) were assessed for systematic and scoping reviews. Data were synthesized by mechanistic domain. Results Sixty-two reviews were included. Systematic reviews (n = 35), narrative reviews (n = 24), and scoping reviews (n = 4) of asymptomatic (n = 37), symptomatic (n = 43), non-specified human subjects (n = 7) and animals (n = 7) were included. Reviews of moderate quality supported neurovascular, neurological, and neurotransmitter/neuropeptide changes. Reviews of low quality supported neuroimmunce, neuromuscular, and neuroendocrine changes. Reviews of critically low quality support biomechanical changes. Conclusions Findings support critically low to moderate quality evidence of complex multisystem mechanistic responses occurring with the application of MT. Results support peripheral, segmental spinal, and supraspinal mechanisms occurring with the application of MT, which can be measured directly or indirectly. The clinical value of these findings has not been well established. While MT has proven to be an effective intervention to treat conditions such as pain, the current body of literature leaves uncertainty as to ‘why’ MT interventions work, and future research should look to better define which mechanisms (or combinations of mechanisms) are mediators of clinical response.

Guo Y., Gong Z., Liu X., Ai K., Li W., Li J.

Background: Low back pain (LBP) is one of the most common symptoms prompting patients to seek treatment. Manual therapy is widely used to treat LBP. Nevertheless, there is a scarcity of bibliometric analyses examining the worldwide utilization of manual therapy for the treatment of LBP. Methods: This research used the Online Bibliometric overview Platform website (https://bibliometric.com), CiteSpace (6.2.R4), and VOSviewer (1.6.19) to provide a comprehensive analysis of the current status and prospective developments in the field. The Web of Science Core Collection (WOSCC) database was searched for publications from August 1, 2013, to August 1, 2023 on manual therapy of low back pain. Results: Among the identified articles, 488 fit the criteria. The number of papers on manual therapy for LBP has progressively risen over in the past 10 years, whereas the average number of citations of these papers has decreased. The leading countries producing publications on this discipline were the USA, Canada, and China. There were 345 authors of the studies, with Christine M. Goertz having the most publications. The University of Southern Denmark was the institution that contributed the most to the field. The Journal of Manipulative and Physiological Therapeutics published many of the research papers in this field. Keyword analysis showed that the relationship between low back pain, spinal manipulation, and management has been present throughout the development of this research area. Conclusions: Spinal manipulation, management, randomized controlled trials, Physical therapy, care and disability are the current research hotspots in the treatment of LBP with manual therapy. In addition, research on complementary medicine and clinical practice guidelines may become an important trend in the future.

Roseen E.J., Bussières A., Reichman R., Bora C., Trieu J., Austad K., Williams C., Fischer R.A., Parrilla D., Laird L.D., LaValley M., Evans R.L., Saper R.B., Morone N.E.

Abstract Introduction Limited adoption of first line treatments for low back pain (LBP) in primary care settings may contribute to an overreliance on pain medications by primary care providers (PCPs). While chiropractic care typically includes recommended nonpharmacologic approaches (e.g., manual therapy, exercise instruction, advice on self-care), implementation strategies to increase adoption of chiropractic care for LBP in primary care clinics are understudied, particularly in underserved communities. Methods We will use a stepped-wedge cluster randomized controlled pilot trial design to evaluate the feasibility of a multi-level implementation strategy to increase adoption of chiropractic care for LBP in primary care clinics at community health centers. Key barriers and facilitators identified by site champions and other key stakeholders will help us to develop and tailor implementation strategies including educational materials and meetings, developing a network of local chiropractors, and modifying the electronic health record to facilitate referrals. Three primary care clinics will be randomized to receive the implementation strategy first, second, or third over a fourteen-month study period. At our first clinic, we will have a four-month pre-implementation period, a two-month implementation deployment period, and a subsequent eight-month follow-up period. We will stagger the start of our implementation strategy, beginning in a new clinic every two months. We will evaluate the proportion of patients with LBP who receive a referral to chiropractic care in the first 21 days after their index visit with PCP. We will also evaluate adoption of other guideline concordant care (e.g., other nonpharmacologic treatments) and non-guideline concordant care (e.g., opioids, imaging) over the study period. Discussion LBP is currently the leading cause of disability worldwide. While there are several treatment options available for individuals with LBP, patients in underserved populations do not often access recommended nonpharmacologic treatment options such as chiropractic care. The results from this study will inform the development of practical implementation strategies that may improve access to chiropractic care for LBP in the primary care context. Furthermore, results may also inform policy changes needed to expand access to chiropractic care in underserved communities. Clintrials.gov NCT# NCT06104605.

Mamud-Meroni L., Tarcaya G.E., Carrasco-Uribarren A., Rossettini G., Flores-Cortes M., Ceballos-Laita L.

The increasing interest in complementary and alternative medicines (CAMs) for musculoskeletal care has sparked significant debate, particularly regarding their biological plausibility and clinical effectiveness. This comprehensive review critically examines the use of two of the most widely utilized CAMs—osteopathy and chiropractic care—over the past 25 years, focusing on their biological plausibility, clinical effectiveness, and potential mechanisms of action. Our analysis of current research and clinical studies reveals that osteopathy and chiropractic are based on concepts such as “somatic dysfunction” and “vertebral subluxation”, which lack robust empirical validation. While these therapies are often presented as credible treatment options, studies evaluating their effectiveness frequently exhibit serious methodological flaws, providing insufficient empirical support for their recommendation as first-line treatments for musculoskeletal conditions. The effects and mechanisms underlying osteopathy and chiropractic remain poorly understood. However, placebo responses—mediated by the interaction of contextual, psychological, and non-specific factors—appear to play a significant role in observed outcomes. The integration of therapies with limited biological plausibility, whose effects may primarily rely on placebo effects, into healthcare systems raises important ethical dilemmas. This review highlights the need for rigorous adherence to scientific principles and calls for a more comprehensive investigation into biobehavioral, contextual, and psychosocial factors that interact with the specific effects of these interventions. Such efforts are essential to advancing our understanding of CAMs, enhancing clinical decision-making, promoting ethical practices, and guiding future research aimed at improving patient care in musculoskeletal disorders.

Yalfani A., Asgarpoor A.

Muñoz Laguna J., Kurmann A., Hofstetter L., Nyantakyi E., Braun J., Clack L., Bang H., Farshad M., Foster N.E., Puhan M.A., Hincapié C.A., Mühlemann M., Caviezel C., Ehrler M., Häusler M., et. al.

Abstract Background Blinding is essential for mitigating biases in trials of low back pain (LBP). Our main objectives were to assess the feasibility of blinding: (1) participants randomly allocated to active or placebo spinal manual therapy (SMT), and (2) outcome assessors. We also explored blinding by levels of SMT lifetime experience and recent LBP, and factors contributing to beliefs about the assigned intervention. Methods A two-parallel-arm, single-centre, placebo-controlled, blinding feasibility trial. Adults were randomised to active SMT (n = 40) or placebo SMT (n = 41). Participants attended two study visits for their assigned intervention, on average seven days apart. The primary outcome was participant blinding (beliefs about assigned intervention) using the Bang blinding index (BI) at two study visits. The Bang BI is arm-specific, chance-corrected, and ranges from − 1 (all incorrect beliefs) to 1 (all correct beliefs), with 0 indicating equal proportions of correct and incorrect beliefs. Secondary outcomes included factors contributing to beliefs about the assigned intervention. Results Of 85 adults screened, 81 participants were randomised (41 [51%] with SMT lifetime experience; 29 [39%] with recent LBP), and 80 (99%) completed follow-up. At study visit 1, 50% of participants in the active SMT arm (Bang BI: 0.50 [95% confidence interval (CI), 0.26 to 0.74]) and 37% in the placebo SMT arm (0.37 [95% CI, 0.10 to 0.63]) had a correct belief about their assigned intervention, beyond chance. At study visit 2, BIs were 0.36 (0.08 to 0.64) and 0.29 (0.01 to 0.57) for participants in the active and placebo SMT arms, respectively. BIs among outcome assessors suggested adequate blinding at both study visits (active SMT: 0.08 [− 0.05 to 0.20] and 0.03 [− 0.11 to 0.16]; placebo SMT: − 0.12 [− 0.24 to 0.00] and − 0.07 [− 0.21 to 0.07]). BIs varied by participant levels of SMT lifetime experience and recent LBP. Participants and outcome assessors described different factors contributing to their beliefs. Conclusions Adequate blinding of participants assigned to active SMT may not be feasible with the intervention protocol studied, whereas blinding of participants in the placebo SMT arm may be feasible. Blinding of outcome assessors seemed adequate. Further methodological work on blinding of SMT is needed. Trial registration number NCT05778396.

Gish B., Jahja E., Nenos V.

Steinhäuser J.

Nugraha W.S., Szakos D., Süth M., Kasza G.

De la Ruelle L.P., de Zoete A., Ostelo R., de Wit G.A., Donker M.H., Rubinstein S.M.

The smallest worthwhile effect (SWE) is the smallest beneficial effect of an intervention that justifies the costs, risks, and inconveniences. The objective is to establish the SWE of spinal manipulative therapy (SMT) for the treatment of low back pain (LBP), and to gain insight into how different attributes of the treatment are traded among each other when choosing SMT. Part 1. A mixed-methods study will be conducted to establish and prioritize a list of attributes influencing choices for those who consider SMT for the treatment of LBP. Individual interviews and consensus groups with chiropractors, manual therapists, and osteopaths and their patients will be conducted. Interviews and consensus groups will be voice-recorded and transcribed verbatim. Part 2. A Discrete Choice Experiment (DCE) will be conducted among people with LBP who have limited to no experience with SMT. Participants will be recruited through an online independent panel company. The survey will consist of several choice sets with attributes and their levels established from Part 1. The DCE will be preceded by a short survey to understand the clinical aspects (i.e. presentation, history and previous treatment for LBP) as well as socio-demographic characteristics of the participants.

Lo C.N., Tsang E.W., Ngai S.P.

Background Spinal manipulation has been increasingly researched over the past two decades for its potential to enhance motor function. In our review, we use the term Neuromuscular Spinal Manipulation (NSM) to specifically identify studies focused on the motor facilitation effects of spinal manipulation. Objective To evaluate the efficacy of NSM in increasing muscle strength among healthy individuals through a systematic review and meta-analysis. Design Systematic Review and Meta-Analysis Methods Databases including PubMed Central, Virtual Health Library, Cochrane Library, OSTMED.DR, and Google Scholar were searched up to September 2023. Eligible studies were randomized controlled trials and crossover studies on adults aged 18-65, assessing high-velocity, low-amplitude thrusts and Maitland grade III or IV mobilizations. Exclusions were studies on patients with pain/pathology, peripheral joint interventions, instrumental mobilizations, or co-interventions. Quality was appraised using the PEDro scale, and evidence graded with the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) approach. This review was registered with PROSPERO (CRD42022351923). Results Of 7308 records, 10 articles met inclusion criteria, with 8 undergoing meta-analysis. A significant pooled effect on isometric muscle strength was observed (standardized mean difference +0.95, 95% CI +0.62 to +1.29) between NSM and controls, with heterogeneity I2 = 38%. A high level of GRADE recommendation was; proposed according to the quality of evidence. Conclusion NSM significantly enhances short-term isometric muscle strength in asymptomatic individuals, underscoring its potential clinical utility. Future research should aim to address the limitations noted, particularly regarding the long-term effects and underlying mechanisms of NSM.

Nyiroe L., Doerig M., Suter M., Connolly L., Vogel N., Stadler C., John-Cedere G., Schweinhardt P., Meier M.L.

AbstractManual therapy, such as spinal manipulation (SM), is commonly used to treat non-specific chronic low back pain (CLBP), although its mechanisms remain poorly understood. It has been hypothesized that the mechanical forces applied during spinal manipulation (SM) influence proprioceptive function, which is often impaired in patients with CLBP. This study aimed to investigate the effect of a single SM intervention on lumbar proprioceptive function and its potential relationship with analgesic effects in patients with CLBP. In a single-blind randomized controlled trial, data from 142 adults with or without CLBP were analyzed after random assignment to receive lumbar spinal manipulation (LMANIP), lumbar mobilization (LMOB), or no intervention (NI). The primary outcome was the proprioceptive weighting (PW) ratio, which reflects the central nervous system’s preferred source of proprioceptive input for balance control, specifically from the lumbar and ankle muscles. PW ratios were assessed immediately before and after intervention by analyzing postural sway changes during vibrotactile stimulation (60 Hz). PW changed in both healthy participants and patients after the intervention, with a significantly stronger lumbar-steered PW following LMANIP compared to NI (β = -0.047, t(422) = -2.71, p = 0.007) and LMOB (β = -0.039, t(422) = - 2.17, p = 0.030). Moreover, LMANIP was particularly effective in reducing pain in patients with stronger lumbar-steered PW before intervention (p < 0.017). These findings suggest that a single SM session enhances proprioceptive input from the lumbar muscles and that the strength of the analgesic effect is associated with the baseline PW status.

Haavik H., Niazi I.K., Amjad I., Kumari N., Ghani U., Ashfaque M., Rashid U., Navid M.S., Kamavuako E.N., Pujari A.N., Holt K.

Objectives: This study aimed to elucidate the mechanisms of chiropractic care using resting electroencephalography (EEG), somatosensory evoked potentials (SEPs), clinical health assessments (Fitbit), and Patient-reported Outcomes Measurement Information System (PROMIS-29). Methods: Seventy-six people with chronic low back pain (mean age ± SD: 45 ± 11 years, 33 female) were randomised into control (n = 38) and chiropractic (n = 38) groups. EEG and SEPs were collected pre and post the first intervention and post 4 weeks of intervention. PROMIS-29 was measured pre and post 4 weeks. Fitbit data were recorded continuously. Results: Spectral analysis of resting EEG showed a significant increase in Theta, Alpha and Beta, and a significant decrease in Delta power in the chiropractic group post intervention. Source localisation revealed a significant increase in Alpha activity within the Default Mode Network (DMN) post intervention and post 4 weeks. A significant decrease in N30 SEP peak amplitude post intervention and post 4 weeks was found in the chiropractic group. Source localisation demonstrated significant changes in Alpha and Beta power within the DMN post-intervention and post 4 weeks. Significant improvements in light sleep stage were observed in the chiropractic group along with enhanced overall quality of life post 4 weeks, including significant reductions in anxiety, depression, fatigue, and pain. Conclusions: These findings indicate that many health benefits of chiropractic care are due to altered brain activity.