Validation of a novel sham cervical manipulation procedure

Comparison of the Effects of Cervical Thrust Manipulation and Exercise in Mechanical Neck Pain: A Randomized Controlled Trial

OBJECTIVE

This study aimed to compare the effectiveness of cervical thrust manipulation and exercise in patients with mechanical neck pain (MNP).

METHOD

Sixty (mean age 31.45 ± 7.31 years) patients were randomized into three groups: manipulation (Group 1); exercise (Group 2); and manipulation plus exercise (Group 3). All interventions were performed 2 days a week for 6 weeks. The visual analog scale (VAS) and Neck Disability Index (NDI) were primary outcome measures; pressure pain threshold (PPT), range of motion (ROM), Short form-36 (SF-36), and Global Rating of Change (GROC) were secondary outcome measures.

RESULTS

All parameters improved in all groups (p < .05). Only the minimal clinically important difference (MCID) for NDI was achieved in Group 3. Group 3 had greater improvement in: VAS-rest (p = .004); NDI (p < .001); PPT-left (p = .012); and vitality (p = .002), as well as higher GROC compared to the other groups (p = .043). Group 3 was superior to Group 2 in terms of: ROM (Lateral flexion [LF]-right, p = .003/left, p = .003, rotation-right, p = .012/left, p = .010), PPT-right (p = .022); and emotional well-being (p = .003). Group 1 was superior to Group 2 in terms of ROM (LF-left, p = .043/rotation-left, p = .049). The between-group effect sizes were large (0.12-0.36).

CONCLUSION

The combined application of cervical thrust manipulation and exercise in MNP resulted in greater improvement in clinical parameters, especially function, and higher patient satisfaction in the short term compared to their application alone. Because of its positive effects, cervical thrust manipulation can be added to the exercise program according to the patient's needs and suitability for manipulation.

Blinding and sham control methods in trials of physical, psychological, and self-management interventions for pain (article II): a meta-analysis relating methods to trial results

ABSTRACT

Sham interventions in randomized clinical trials (RCTs) of physical, psychological, and self-management (PPS) therapies for pain are highly variable in design and believed to contribute to poor internal validity. However, it has not been formally tested whether the extent to which sham controls resemble the treatment under investigation consistently affects trial outcomes, such as effect sizes, differential attrition, participant expectancy, and blinding effectiveness. Placebo- or sham-controlled RCTs of PPS interventions of clinical pain populations were searched in 12 databases. The similarity of control interventions to the experimental treatment was rated across 25 features. Meta-regression analyses assessed putative links between employed control interventions, observed effect sizes in pain-related outcomes, attrition, and blinding success. The sample included 198 unique control interventions, dominated by manual therapy and chronic musculoskeletal pain research. Meta-analyses indicated small-to-moderate benefits of active treatments over control interventions, across subgroups of manual therapies, exercise, and rehabilitation, and psychological intervention trials. Multiple meta-regression modelling demonstrated that similarity between sham control and tested interventions predicted variability in pain-related outcomes, attrition, and blinding effectiveness. Influential variables were differences relating to the extent of intervention exposure, participant experience, and treatment environments. The results support the supposed link between blinding methods and effect sizes, based on a large and systematically sourced overview of methods. However, challenges to effective blinding are complex and often difficult to discern from trial reports. Nonetheless, these insights have the potential to change trial design, conduct, and reporting and will inform guideline development.

Blinding and sham control methods in trials of physical, psychological, and self-management interventions for pain (article I): a systematic review and description of methods

ABSTRACT

Blinding is challenging in randomised controlled trials of physical, psychological, and self-management therapies for pain, mainly because of their complex and participatory nature. To develop standards for the design, implementation, and reporting of control interventions in efficacy and mechanistic trials, a systematic overview of currently used sham interventions and other blinding methods was required. Twelve databases were searched for placebo or sham-controlled randomised clinical trials of physical, psychological, and self-management treatments in a clinical pain population. Screening and data extraction were performed in duplicate, and trial features, description of control methods, and their similarity to the active intervention under investigation were extracted (protocol registration ID: CRD42020206590). The review included 198 unique control interventions, published between 2008 and December 2021. Most trials studied people with chronic pain, and more than half were manual therapy trials. The described control interventions ranged from clearly modelled based on the active treatment to largely dissimilar control interventions. Similarity between control and active interventions was more frequent for certain aspects (eg, duration and frequency of treatments) than others (eg, physical treatment procedures and patient sensory experiences). We also provide an overview of additional, potentially useful methods to enhance blinding, as well as the reporting of processes involved in developing control interventions. A comprehensive picture of prevalent blinding methods is provided, including a detailed assessment of the resemblance between active and control interventions. These findings can inform future developments of control interventions in efficacy and mechanistic trials and best-practice recommendations.

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

BACKGROUND

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

METHOD

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

RESULTS

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

Fascial treatment versus manual therapy (HVLA) in patients with chronic neck pain: A randomized controlled trial

BACKGROUND

Chronic neck pain (CNP) is a common health problem in western industrialized nations. In recent years, the fascial tissue has attracted the attention of therapists, and a treatment of the fasciae promises to be a meaningful approach in the therapy of patients with CNP.

OBJECTIVE

The aim of this study was to investigate the effectiveness of a fascial treatment (FT) compared to manual therapy (MT) and to no intervention (control group, CG) in patients with CNP.

METHODS

Sixty participants with CNP were randomized into three groups. Primary outcome parameters were pain intensity as measured by the visual analogue scale (VAS), and severity of illness as measured by the Neck Pain and Disability Scale (NPAD). Secondary outcome parameter was the range of motion (ROM) of the cervical spine.

RESULTS

Repeated measures t-tests demonstrated significant decreases with medium to large effect sizes for the FT (VAS: dR⁢M= 1.14; NPAD: dR⁢M= 0.51) and for the MT (VAS: dR⁢M= 1.15; NPAD: dR⁢M= 0.72).

CONCLUSION

Our results confirmed the effectiveness of MT on pain and severity of illness in the treatment of patients suffering from CNP. Furthermore, the results demonstrated the effectiveness and clinical relevance of FT for this population.

Clinical Effectiveness and Efficacy of Chiropractic Spinal Manipulation for Spine Pain

Spine pain is a highly prevalent condition affecting over 11% of the world's population. It is the single leading cause of activity limitation and ranks fourth in years lost to disability globally, representing a significant personal, social, and economic burden. For the vast majority of patients with back and neck pain, a specific pathology cannot be identified as the cause for their pain, which is then labeled as non-specific. In a growing proportion of these cases, pain persists beyond 3 months and is referred to as chronic primary back or neck pain. To decrease the global burden of spine pain, current data suggest that a conservative approach may be preferable. One of the conservative management options available is spinal manipulative therapy (SMT), the main intervention used by chiropractors and other manual therapists. The aim of this narrative review is to highlight the most relevant and up-to-date evidence on the effectiveness (as it compares to other interventions in more pragmatic settings) and efficacy (as it compares to inactive controls under highly controlled conditions) of SMT for the management of neck pain and low back pain. Additionally, a perspective on the current recommendations on SMT for spine pain and the needs for future research will be provided. In summary, SMT may be as effective as other recommended therapies for the management of non-specific and chronic primary spine pain, including standard medical care or physical therapy. Currently, SMT is recommended in combination with exercise for neck pain as part of a multimodal approach. It may also be recommended as a frontline intervention for low back pain. Despite some remaining discrepancies, current clinical practice guidelines almost universally recommend the use of SMT for spine pain. Due to the low quality of evidence, the efficacy of SMT compared with a placebo or no treatment remains uncertain. Therefore, future research is needed to clarify the specific effects of SMT to further validate this intervention. In addition, factors that predict these effects remain to be determined to target patients who are more likely to obtain positive outcomes from SMT.

Neurophysiological mechanisms of chiropractic spinal manipulation for spine pain

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

Context matters: the psychoneurobiological determinants of placebo, nocebo and context-related effects in physiotherapy

Background

Placebo and nocebo effects embody psychoneurobiological phenomena where behavioural, neurophysiological, perceptive and cognitive changes occur during the therapeutic encounter in the healthcare context. Placebo effects are produced by a positive healthcare context; while nocebo effects are consequences of negative healthcare context. Historically, placebo, nocebo and context-related effects were considered as confounding elements for clinicians and researchers. In the last two decades this attitude started to change, and the understanding of the value of these effects has increased. Despite the growing interest, the knowledge and the awareness of using the healthcare context to trigger placebo and nocebo effects is currently limited and heterogeneous among physiotherapists, reducing their translational value in the physiotherapy field.

Objectives

To introduce the placebo, nocebo and context-related effects by: (1) presenting their psychological models; (2) describing their neurophysiological mechanisms; (3) underlining their impact for the physiotherapy profession; and (4) tracing lines for future researches.

Conclusion

Several psychological mechanisms are involved in placebo, nocebo and context-related effects; including expectation, learning processes (classical conditioning and observational learning), reinforced expectations, mindset and personality traits. The neurophysiological mechanisms mainly include the endogenous opioid, the endocannabinoid and the dopaminergic systems. Neuroimaging studies have identified different brain regions involved such as the dorsolateral prefrontal cortex, the rostral anterior cingulate cortex, the periaqueductal gray and the dorsal horn of spine. From a clinical perspective, the manipulation of the healthcare context with the best evidence-based therapy represents an opportunity to trigger placebo effects and to avoid nocebo effects respecting the ethical code of conduct. From a managerial perspective, stakeholders, organizations and governments should encourage the assessment of the healthcare context aimed to improve the quality of physiotherapy services. From an educational perspective, placebo and nocebo effects are professional topics that should be integrated in the university program of health and medical professions. From a research perspective, the control of placebo, nocebo and context-related effects offers to the scientific community the chance to better measure the impact of physiotherapy on different outcomes and in different conditions through primary studies.

Changes in Cervicocephalic Kinesthetic Sensibility, Widespread Pressure Pain Sensitivity, and Neck Pain After Cervical Thrust Manipulation in Patients With Chronic Mechanical Neck Pain: A Randomized Clinical Trial

OBJECTIVE

The purpose of the current randomized clinical trial was to examine the effects of cervical thrust manipulation or sham manipulation on cervicocephalic kinaesthetic sense, pain, pain-related disability, and pressure pain sensitivity in patients with mechanical neck pain.

METHODS

Fifty-four individuals with neck pain were randomly assigned to receive either a cervical manipulation (right or left) or a sham manipulation. Immediate outcomes included cervical kinesthetic sense as assessed by joint position sense error (JPSE) and pressure pain thresholds (PPTs). At 1 week, neck pain intensity (numerical pain rate scale) and neck pain-related disability (Neck Disability Index [NDI]) outcomes were also collected.

RESULTS

The mixed-model analysis of covariance revealed a significant group × time interaction in favor of the cervical thrust manipulation group for the JPSE on rotation and extension. There was also a significant interaction for changes in PPTs at C5 to C6 and tibialis anterior. At the 1-week follow-up, a significant interaction existed for neck-related disability but not for neck pain at rest, worst pain, or lowest pain experienced the preceding week.

CONCLUSIONS

Our results suggest that cervical spine thrust manipulation improves JPSE, PPT and NDI in participants with chronic mechanical neck pain. Furthermore, changes in JPSE and NDI were large and surpass published minimal detectable changes for these outcome measures. In addition, the effect sizes of PPTs were medium; however, only C5 to C6 zygapophyseal joint exceeded the minimal detectable change. In contrast, cervical thrust manipulation did not improve neck pain intensity at 1 week after the intervention.

Overdispersion models for correlated multinomial data: Applications to blinding assessment

Overdispersion models have been extensively studied for correlated normal and binomial data but much less so for correlated multinomial data. In this work, we describe a multinomial overdispersion model that leads to the specification of the first two moments of the outcome and allows the estimation of the global parameters using generalized estimating equations (GEE). We introduce a Global Blinding Index as a target parameter and illustrate the application of the GEE method to its estimation from (1) a clinical trial with clustering by practitioner and (2) a meta-analysis on psychiatric disorders. We examine the impact of a small number of clusters, high variability in cluster sizes, and the magnitude of the intraclass correlation on the performance of the GEE estimators of the Global Blinding Index using the data simulated from different models. We compare these estimators with the inverse-variance weighted estimators and a maximum-likelihood estimator, derived under the Dirichlet-multinomial model. Our results indicate that the performance of the GEE estimators was satisfactory even in situations with a small number of clusters, whereas the inverse-variance weighted estimators performed poorly, especially for larger values of the intraclass correlation coefficient. Our findings and illustrations may be instrumental for practitioners who analyze clustered multinomial data from clinical trials and/or meta-analysis.

The Effects Induced by Spinal Manipulative Therapy on the Immune and Endocrine Systems

Background and Objectives: Spinal manipulations are interventions widely used by different healthcare professionals for the management of musculoskeletal (MSK) disorders. While previous theoretical principles focused predominantly on biomechanical accounts, recent models propose that the observed pain modulatory effects of this form of manual therapy may be the result of more complex mechanisms. It has been suggested that other phenomena like neurophysiological responses and the activation of the immune-endocrine system may explain variability in pain inhibition after the administration of spinal manipulative therapy (SMT). The aim of this paper is to provide an overview of the available evidence supporting the biological plausibility of high-velocity, low-amplitude thrust (HVLAT) on the immune-endocrine system. Materials and Methods: Narrative critical review. An electronic search on MEDLINE, ProQUEST, and Google Scholar followed by a hand and "snowballing" search were conducted to find relevant articles. Studies were included if they evaluated the effects of HVLAT on participants' biomarkers Results: The electronic search retrieved 13 relevant articles and two themes of discussion were developed. Nine studies investigated the effects of SMT on cortisol levels and five of them were conducted on symptomatic populations. Four studies examined the effects of SMT on the immune system and all of them were conducted on healthy individuals. Conclusions: Although spinal manipulations seem to trigger the activation of the neuroimmunoendocrine system, the evidence supporting a biological account for the application of HVLAT in clinical practice is mixed and conflicting. Further research on subjects with spinal MSK conditions with larger sample sizes are needed to obtain more insights about the biological effects of spinal manipulative therapy.

Manipulation and Mobilization for Treating Chronic Nonspecific Neck Pain: A Systematic Review and Meta-Analysis for an Appropriateness Panel

BACKGROUND

Mobilization and manipulation therapies are widely used by patients with chronic nonspecific neck pain; however, questions remain around efficacy, dosing, and safety, as well as how these approaches compare to other therapies.

OBJECTIVES

Based on published trials, to determine the efficacy, effectiveness, and safety of various mobilization and manipulation therapies for treatment of chronic nonspecific neck pain.

STUDY DESIGN

A systematic literature review and meta-analysis.

METHODS

We identified studies published between January 2000 and September 2017, by searching multiple electronic databases, examining reference lists, and communicating with experts. We selected randomized controlled trials comparing manipulation and/or mobilization therapies to sham, no treatment, each other, and other active therapies, or when combined as multimodal therapeutic approaches. We assessed risk of bias by using the Scottish Intercollegiate Guidelines Network criteria. When possible, we pooled data using random-effects meta-analysis. Grading of Recommendations, Assessment, Development, and Evaluation was applied to determine the confidence in effect estimates. This project was funded by the National Center for Complementary and Integrative Health under award number U19AT007912 and ultimately used to inform an appropriateness panel.

RESULTS

A total of 47 randomized trials (47 unique trials in 53 publications) were included in the systematic review. These studies were rated as having low risk of bias and included a total of 4,460 patients with nonspecific chronic neck pain who were being treated by a practitioner using various types of manipulation and/or mobilization interventions. A total of 37 trials were categorized as unimodal approaches and involved thrust or nonthrust compared with sham, no treatment, or other active comparators. Of these, only 6 trials with similar intervention styles, comparators, and outcome measures/timepoints were pooled for meta-analysis at 1, 3, and 6 months, showing a small effect in favor of thrust plus exercise compared to an exercise regimen alone for a reduction in pain and disability. Multimodal approaches appeared to be effective at reducing pain and improving function from the 10 studies evaluated. Health-related quality of life was seldom reported. Some 22/47 studies did not report or mention adverse events. Of the 25 that did, either no or minor events occurred.

LIMITATIONS

The current evidence is heterogeneous, and sample sizes are generally small.

CONCLUSIONS

Studies published since January 2000 provide low-moderate quality evidence that various types of manipulation and/or mobilization will reduce pain and improve function for chronic nonspecific neck pain compared to other interventions. It appears that multimodal approaches, in which multiple treatment approaches are integrated, might have the greatest potential impact. The studies comparing to no treatment or sham were mostly testing the effect of a single dose, which may or may not be helpful to inform practice. According to the published trials reviewed, manipulation and mobilization appear safe. However, given the low rate of serious adverse events, other types of studies with much larger sample sizes would be required to fully describe the safety of manipulation and/or mobilization for nonspecific chronic neck pain.

KEY WORDS

Chronic neck pain, nonspecific, chiropractic, manipulation, mobilization, systematic review, meta-analysis, appropriateness.

The effects of a single session of chiropractic care on strength, cortical drive, and spinal excitability in stroke patients

The objective of this study was to investigate whether a single session of chiropractic care could increase strength in weak plantar flexor muscles in chronic stroke patients. Maximum voluntary contractions (strength) of the plantar flexors, soleus evoked V-waves (cortical drive), and H-reflexes were recorded in 12 chronic stroke patients, with plantar flexor muscle weakness, using a randomized controlled crossover design. Outcomes were assessed pre and post a chiropractic care intervention and a passive movement control. Repeated measures ANOVA was used to asses within and between group differences. Significance was set at p < 0.05. Following the chiropractic care intervention there was a significant increase in strength (F (1,11) = 14.49, p = 0.002; avg 64.2 ± 77.7%) and V-wave/Mmax ratio (F(1,11) = 9.67, p = 0.009; avg 54.0 ± 65.2%) compared to the control intervention. There was a significant strength decrease of 26.4 ± 15.5% (p = 0.001) after the control intervention. There were no other significant differences. Plantar flexor muscle strength increased in chronic stroke patients after a single session of chiropractic care. An increase in V-wave amplitude combined with no significant changes in H-reflex parameters suggests this increased strength is likely modulated at a supraspinal level. Further research is required to investigate the longer term and potential functional effects of chiropractic care in stroke recovery.

Endocrine response after cervical manipulation and mobilization in people with chronic mechanical neck pain: a randomized controlled trial

BACKGROUND

Most of the research on the effects of spinal manipulation on endocrine function has been done on healthy subjects and has yielded contradictory results. The potential role of cervical manual therapy intervention in order to induce changes in the endocrine system has not yet been investigated.

AIM

The aim of this trial is to compare the effects on salivary cortisol levels and clinical outcomes of cervical manipulation versus cervical mobilization or sham manipulation in patients with chronic mechanical neck pain.

DESIGN

Randomized controlled trial.

SETTING

University of Alcala de Henares: outpatient (referrals from office workers).

POPULATION

A total of 83 patients with chronic mechanical neck pain.

METHODS

Participants were randomized to receive one session of cervical manipulation, cervical mobilization, or sham manipulation. The measured variables were salivary cortisol levels, neck pain and disability, pressure pain thresholds (PPT), and cervical range of motion (ROM). They were obtained at baseline, immediately after treatment (except neck disability), and at one-week follow-up (except cortisol).

RESULTS

A significant and comparable increase in cortisol levels was observed immediately after cervical manipulation and mobilization (both P<0.001). Neck disability improved to a similar degree in the cervical manipulation and mobilization groups at the one-week follow-up (both P<0.001). Neck pain was reduced immediately after cervical manipulation (P<0.001), cervical mobilization (P=0.001), and sham manipulation (P<0.001). There were no significant changes in most ROM directions after either treatment. No significant interaction effect was observed for PPT.

CONCLUSIONS

Cervical manipulation and mobilization resulted in a similar increase in cortisol concentrations immediately post-treatment in people with chronic mechanical neck pain. Supraspinal mechanisms may thus play a role in the hypoalgesic effects that follow the application of both interventions.

CLINICAL REHABILITATION IMPACT

The increase in cortisol levels was similar with cervical manipulation and mobilization so induced stress levels can be similar in both interventions.

The Influence of Treatment Expectations on Clinical Outcomes and Cortisol Levels in Patients With Chronic Neck Pain: An Experimental Study

BACKGROUND

The role of contextual factors like pre-existing treatment expectations has been established. However, the effect of verbally delivered treatment expectations in patient-therapist communication has not been considered, nor has the role of cortisol changes within the placebo/nocebo response in people with chronic neck pain.

OBJECTIVE

To examine the effect of verbally delivered treatment expectations on clinical outcomes in physical therapy practice and to determine if changes in cortisol levels are associated with changes in neck pain and disability.

METHODS

Eighty-three patients with chronic neck pain were randomly allocated to 3 different verbally delivered expectations (positive, negative, neutral) during physical therapy interventions.

MAIN OUTCOME MEASURES

salivary cortisol, pain and disability, and cervical range of motion.

RESULTS

Pain significantly improved in the positive (P < 0.001) and neutral (P < 0.001) expectations groups. For salivary cortisol levels, a significant increase was observed in response to treatment in the neutral (P = 0.045) and negative (P < 0.001) expectations groups. No significant correlations were found between changes in salivary cortisol levels and the change in pain in the neutral and negative expectations groups.

CONCLUSIONS

Physical therapists treating people with chronic neck pain should be attentive when communicating the expected treatment effects to their patients. Whereas verbally delivered positive or neutral expectations may be beneficial for pain-related measures, giving negative expectations may result in a lack of a treatment response on pain. Cortisol levels increased in response to verbally delivered neutral and negative expectations, in the absence of a nocebo effect. This questions the presumed role of cortisol in the nocebo effect.

Transcutaneous electrical nerve stimulation and cervical joint manipulation on pressure pain threshold

Aim: Transcutaneous electrical nerve stimulation (TENS) and cervical joint manipulation (CJM) are often used for pain treatment. Methods: A total of 144 healthy subjects will be randomly allocated into four groups: active TENS and CJM, placebos TENS and CJM, placebo TENS and active CJM, active TENS and placebo CJM. TENS will be applied for 20 min followed by CJM. All subjects will be assessed before, during and after interventions, using a digital pressure algometer. Discussion: This is the first study to assess the combined effects of TENS and CJM on pressure pain threshold in healthy individuals. It is possible that both methods combined can enhance the hypoalgesic effect because they activate different analgesic pathways.

Study registration: NCT03531541 (ClinicalTrials.gov).

Relationship Between Subjective Experience of Individuals, Practitioner Seniority, Cavitation Occurrence, and 3-Dimensional Kinematics During Cervical Spine Manipulation

OBJECTIVE

The purpose of this study was to assess individual subjective experience (ISE) of the recipients of a cervical manipulation and to analyze the influence of kinematics, cavitation occurrence, and practitioner seniority on individual experience.

METHODS

Practitioners with different seniority (years of experience) manipulated 20 asymptomatic volunteers at C3 and C5 on both sides. Kinematics were recorded using a 3-dimensional electrogoniometer, and ISE data were gathered through a questionnaire to explore the subjects' experiences of manipulation in terms of tactile sensations, relaxation, perception of the task, and therapist handling. Kinematics, occurrence of cavitation, practitioner's seniority, and ISE data were analyzed concurrently.

RESULTS

Motion parameters obtained during manipulation were found to be influenced by cavitation occurrence and differences between practitioners. Data analysis indicated that ISE could be grouped into 2 factors. The first revolved around grip firmness and range and speed of practitioner's gesture. The second factor represented patient's relaxation and the precision of handling. Also, most ISE data correlated with kinematics, although a subjective measurement did not always correlate the highest with its objective counterpart. When cavitation occurred, ISE ratings were higher, suggesting that participants may associate cavitation with the success of manipulations. Higher practitioner seniority (more years of experience) induced feelings of higher speed, amplitude, firmness, and precision.

CONCLUSIONS

Recipients of cervical manipulation experienced different subjective feelings that can be expressed in 2 dimensions. These feelings are influenced by cavitation occurrence and practitioner's seniority. A better understanding of an individual's subjective experience related to cervical manipulation could increase confidence and improve the patient-therapist relationship, and it may provide further therapeutic perspectives for the practitioners.

Predictive factors for reporting adverse events following spinal manipulation in randomized clinical trials - secondary analysis of a systematic review

While spinal manipulative therapy (SMT) is recommended for the treatment of spinal disorders, concerns exist about adverse events associated with the intervention. Adequate reporting of adverse events in clinical trials would allow for more accurate estimations of incidence statistics through meta-analysis. However, it is not currently known if there are factors influencing adverse events reporting following SMT in randomized clinical trials (RCTs). Thus our objective was to investigate predictive factors for the reporting of adverse events in published RCTs involving SMT. The Physiotherapy Evidence Database (PEDro) and Cochrane Central Register of Controlled Trials (CENTRAL) were searched for RCTs involving SMT. Domains of interest included: sample size; publication date relative to the 2010 CONSORT statement; risk of bias; the region treated; and number of intervention sessions. 7398 records were identified, of which 368 articles were eligible for inclusion. A total of 140 (38.0%) articles reported on adverse events. Articles were more likely to report on adverse events if they possessed larger sample sizes, were published after the 2010 CONSORT statement, had a low risk of bias and involved multiple intervention sessions. The region treated was not a significant predictor for reporting on adverse events. Predictors for reporting on adverse events included larger sample size, publication after the 2010 CONSORT statement, low risk of bias and trials involving multiple intervention sessions. We recommend that researchers focus on developing robust methodologies and participant follow-up regimens for RCTs involving SMT.

The quality of placebos used in randomized, controlled trials of lumbar and pelvic joint thrust manipulation-a systematic review

BACKGROUND CONTEXT

Spinal manipulative therapy (SMT) has been attributed with substantial non-specific effects. Accurate assessment of the non-specific effects of SMT relies on high-quality studies with low risk of bias that compare with appropriate placebos.

PURPOSE

This review aims to characterize the types and qualities of placebo control procedures used in controlled trials of manually applied, lumbar and pelvic (LP)-SMT, and to evaluate the assessment of subject blinding and expectations.

STUDY DESIGN

This is a systematic review of randomized, placebo-controlled trials.

METHODS

We searched MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, Index to Chiropractic Literature, and relevant bibliographies. We included randomized, placebo or sham-controlled trials where the index treatment was manually applied LP-SMT. There were no restrictions on the type of condition being investigated. Two independent reviewers selected the studies, assessed study quality, and extracted the data. Relevant data were the type and quality of placebo control(s) used, the assessment of blinding and expectations, and the results of those assessments.

RESULTS

Twenty-five randomized, placebo-controlled trials were included in this review. There were 18 trials that used a sham manual SMT procedure for their placebo control intervention; the most common approach was with an SMT setup but without the application of any thrust. One small pilot study used an unequivocally indistinguishable placebo, two trials used placebos that had been validated as inert a priori, and eight trials reported on the success of subject blinding. Risk of bias was high or unclear, for all included studies.

CONCLUSIONS

Imperfect placebos are ubiquitous in clinical trials of LP-SMT, and few trials have assessed for successful subject blinding or balanced expectations of treatment success between active and control group subjects. There is thus a strong potential for unmasking of control subjects, unequal non-specific effects between active and control groups, and non-inert placebos in existing trials. Future trials should consider assessing the success of subject blinding and ensuring inertness of their placebo a priori, as a minimum standard for quality.

Effect of two consecutive spinal manipulations in a single session on myofascial pain pressure sensitivity: a randomized controlled trial

OBJECTIVE

To investigate the summative effect of two consecutive spinal manipulative therapy (SMT) interventions within the same session on the pain pressure sensitivity of neurosegmentally linked myofascial tissues.

METHODS

26 participants were recruited and assessed for the presence of a clinically identifiable myofascial trigger point in the right infraspinatus muscle. Participants were randomly assigned to test or control group. Test group received two consecutive real cervical SMT interventions to C5-C6 segment while controls received one real SMT followed by one validated sham SMT intervention to C5-C6 segment. Participants received the two consecutive SMT interventions 30 minutes apart. Pain pressure threshold (PPT) readings were recorded at pre-SMT1 and 5, 10, 15, 20 and 25 minutes post-SMT1 and post-SMT2. PPT readings were normalized to pre-SMT1 values and averaged.

RESULTS

Repeated measures ANOVA demonstrated a significant main effect of SMT intervention [F(1,24)=8.60, p<0.05] but not group [F(1.24)=0.01] (p=0.91). Post-hoc comparisons demonstrated a statistically significant (p<0.05) increase in SMT2 versus SMT1 (18%) in the test group but not in controls (4%) (p=0.82).

CONCLUSIONS

Two consecutive SMT interventions evoke significant decreases in mechanical pressure sensitivity (increased PPT) within neurosegmentally linked myofascial tissues. The antinociceptive effects of SMT may be summative and governed by a dose-response relationship in myofascial tissues.

Validation of Placebo in a Manual Therapy Randomized Controlled Trial

At present, no consensus exists among clinical and academic experts regarding an appropriate placebo for randomized controlled trials (RCTs) of spinal manipulative therapy (SMT). Therefore, we investigated whether it was possible to conduct a chiropractic manual-therapy RCT with placebo. Seventy migraineurs were randomized to a single-blinded placebo-controlled clinical trial that consisted of 12 treatment sessions over 3 months. The participants were randomized to chiropractic SMT or placebo (sham manipulation). After each session, the participants were surveyed on whether they thought they had undergone active treatment (“yes” or “no”) and how strongly they believed that active treatment was received (numeric rating scale 0–10). The outcome measures included the rate of successful blinding and the certitude of the participants’ beliefs in both treatment groups. At each treatment session, more than 80% of the participants believed that they had undergone active treatment, regardless of group allocation. The odds ratio for believing that active treatment was received was >10 for all treatment sessions in both groups (all p < 0.001). The blinding was maintained throughout the RCT. Our results strongly demonstrate that it is possible to conduct a single-blinded manual-therapy RCT with placebo and to maintain the blinding throughout 12 treatment sessions given over 3 months.

Development of an attention-touch control for manual cervical distraction: a pilot randomized clinical trial for patients with neck pain

Background

Manual cervical distraction (MCD) is a traction-based therapy performed with a manual contact over the cervical region producing repeating cycles while patients lie prone. This study evaluated a traction force-based minimal intervention for use as an attention-touch control in clinical trials of MCD for patients with chronic neck pain.

Methods

We conducted a mixed-methods, pilot randomized clinical trial in adults with chronic neck pain. Participants were allocated to three traction force ranges of MCD: low force/minimal intervention (0-20 N), medium force (21-50 N), or high force (51-100 N). Clinicians delivered five treatments over two weeks consisting of three sets of five cycles of MCD at the C5 vertebra and occiput. Traction forces were measured at each treatment. Patient-reported outcomes included a pain visual analogue scale (VAS), Neck Disability Index (NDI), Credibility and Expectancy Questionnaire (CEQ), and adverse effects. A qualitative interview evaluated treatment group allocation perceptions.

Results

We randomized 48 participants, allocating an average of five each month. Forty-five participants completed the trial with three participants lost to follow-up. Most participants were women (65 %) and white (92 %) with a mean (SD) age of 46.8 (12.5) years. Mean traction force values were within the prescribed force ranges for each group at the C5 and occiput levels. Neck pain VAS demonstrated a benefit for high traction force MCD compared to the low force group [adjusted mean difference 15.6; 95 % confidence interval (CI) 1.6 to 29.7]. Participants in the medium traction force group demonstrated improvements in NDI compared to the low force group (adjusted mean difference 3.0; 95 % CI 0.1 to 5.9), as did participants in the high traction force group (adjusted mean difference 2.7; 95 % CI -0.1 to 5.6). CEQ favored the high force group. Most low force participants correctly identified their treatment allocation in the qualitative interview. No serious adverse events were documented.

Conclusions

This pilot study demonstrated the feasibility of a clinical trial protocol and the utility of a traction-based, minimal intervention as an attention-touch control for future efficacy trials of MCD for patients with neck pain.

Trial registration

ClinicalTrials.gov NCT01765751 (Registration Date 30 May 2012)

Determining the level of evidence for the effectiveness of spinal manipulation in upper limb pain: A systematic review and meta-analysis

BACKGROUND

The use of spinal manipulation (SM) for upper limb pain has been advocated based on the concept of regional interdependence. However, its evidence has not been established.

OBJECTIVE

To determine the level of evidence for the effectiveness of SM in patients with upper limb pain as part of the concept of regional interdependence.

METHODS

MeSH and Key words representing two broad subject areas: SM and upper limb disorders were used to conduct an electronic search in sixteen electronic databases. Randomized controlled trials and/or controlled clinical trials investigating the effects of SM in patients with upper limb pain were included. Studies including pain in the neck or scapular region and those using spinal mobilization were excluded. Meta-analysis was conducted to examine the effects of SM on upper limb pain. The overall quality of evidence was assessed using the GRADE system.

RESULTS

Out of 3307 studies, six trials met inclusion criteria for this review. Of these, three studies were included in meta-analysis. Meta-analysis results suggested there were no statistical differences between SM and other interventions in the effects on reducing upper limb pain. The overall quality of evidence was very low.

CONCLUSION

The number of studies regarding the current topic is limited. There is very low quality evidence that SM is not better nor inferior than other interventions in the management of upper limb pain.

Chiropractor interaction and treatment equivalence in a pilot randomized controlled trial: an observational analysis of clinical encounter video-recordings

Background

Chiropractic care is a complex health intervention composed of both treatment effects and non-specific, or placebo, effects. While doctor-patient interactions are a component of the non-specific effects of chiropractic, these effects are not evaluated in most clinical trials. This study aimed to: 1) develop an instrument to assess practitioner-patient interactions; 2) determine the equivalence of a chiropractor’s verbal interactions and treatment delivery for participants allocated to active or sham chiropractic groups; and 3) describe the perceptions of a treatment-masked evaluator and study participants regarding treatment group assignment.

Methods

We conducted an observational analysis of digital video-recordings derived from study visits conducted during a pilot randomized trial of conservative therapies for temporomandibular pain. A theory-based, iterative process developed the 13-item Chiropractor Interaction and Treatment Equivalence Instrument. A trained evaluator masked to treatment assignment coded video-recordings of clinical encounters between one chiropractor and multiple visits of 26 participants allocated to active or sham chiropractic treatment groups. Non-parametric statistics were calculated.

Results

The trial ran from January 2010 to October 2011. We analyzed 111 complete video-recordings (54 active, 57 sham). Chiropractor interactions differed between the treatment groups in 7 categories. Active participants received more interactions with clinical information (8 vs. 4) or explanations (3.5 vs. 1) than sham participants within the therapeutic domain. Active participants received more directions (63 vs. 58) and adjusting instrument thrusts (41.5 vs. 23) in the procedural domain and more optimistic (2.5 vs. 0) or neutral (7.5 vs. 5) outcome statements in the treatment effectiveness domain. Active participants recorded longer visit durations (13.5 vs. 10 minutes). The evaluator correctly identified 61% of active care video-recordings as active treatments but categorized only 31% of the sham treatments correctly. Following the first treatment, 82% of active and 11% of sham participants correctly identified their treatment group. At 2-months, 93% of active and 42% of sham participants correctly identified their group assignment.

Conclusions

Our findings show the feasibility of evaluating doctor-patient interactions in chiropractic clinical trials using video-recordings and standardized instrumentation. Clinical trial design and clinician training protocols should improve and assess the equivalence of doctor-patient interactions between treatment groups.

Trial registration

This trial was registered in ClinicalTrials.gov as NCT01021306 on 24 November 2009.

Retention of blinding at follow-up in a randomized clinical study using a sham-control cervical manipulation procedure for neck pain: secondary analyses from a randomized clinical study

OBJECTIVE

Participants in clinical trials of spinal manipulation have not been rigorously blinded to group assignment. This study reports on secondary analyses of the retention of participant blinding beyond the immediate posttreatment time frame following a single-session, randomized clinical study. A novel control cervical manipulation procedure that has previously been shown to be therapeutically inert was contrasted with a typical manipulation procedure.

METHODS

A randomized clinical study of a single session of typical vs sham-control manipulation in patients with chronic neck pain was conducted. Findings of self-reported group registration at 24 to 48 hours posttreatment were computed. The Blinding Index (BI) of Bang et al was then applied to both the immediate and post-24- to 48-hour results.

RESULTS

Twenty-four to 48 hours after treatment, 94% and 22% of participants in the typical and control groups, respectively, correctly identified their group assignment. When analyzed with the BI of Bang et al, the immediate posttreatment BI for the group receiving a typical manipulation was 0.22 (95% confidence interval [CI], -0.03 to 0.47); for the group receiving a control manipulation, it was 0.19 (95% CI, -0.06 to 0.43). The BI at post-24 hours was as follows: typical = 0.75 (95% CI, 0.59-0.91) and control = -0.34 (95% CI, -0.58 to -0.11).

CONCLUSIONS

This study found that the novel sham-control cervical manipulation procedure may be effective in blinding sham group allocation up to 48 hours posttreatment. It appears that, at 48 hours posttreatment, the modified form of the typical cervical manipulation was not. The sham-control procedure appears to be a promising procedure for future clinical trials.

Intradiscal Pressure Changes during Manual Cervical Distraction: A Cadaveric Study

The objective of this study was to measure intradiscal pressure (IDP) changes in the lower cervical spine during a manual cervical distraction (MCD) procedure. Incisions were made anteriorly, and pressure transducers were inserted into each nucleus at lower cervical discs. Four skilled doctors of chiropractic (DCs) performed MCD procedure on nine specimens in prone position with contacts at C5 or at C6 vertebrae with the headpiece in different positions. IDP changes, traction forces, and manually applied posterior-to-anterior forces were analyzed using descriptive statistics. IDP decreases were observed during MCD procedure at all lower cervical levels C4-C5, C5-C6, and C6-C7. The mean IDP decreases were as high as 168.7 KPa. Mean traction forces were as high as 119.2 N. Posterior-to-anterior forces applied during manual traction were as high as 82.6 N. Intraclinician reliability for IDP decrease was high for all four DCs. While two DCs had high intraclinician reliability for applied traction force, the other two DCs demonstrated only moderate reliability. IDP decreases were greatest during moving flexion and traction. They were progressevely less pronouced with neutral traction, fixed flexion and traction, and generalized traction.