Testing walking performance in patients with low back pain: will two minutes do instead of six minutes?

PURPOSE

The six-minute walk test (6MWT) can assess walking function but is time-consuming. We investigate the correlation of performance over the first two minutes of the 6MWT (2MWT#) and the 6MWT. We also evaluate the 2MWT#'s ability to predict 6MWT results, assess correlations to secondary explanatory outcomes, and assess the ability to discriminate between clinical subgroups.

MATERIAL AND METHODS

A cross-sectional study of 124 participants with LBP. Correlations between the 2MWT# and 6MWT and secondary outcomes were evaluated using the Pearson product-moment correlation coefficient. The predictive ability of the 2MWT# was defined as the residual distance between the observed 6MWT and three times the 2MWT#. Differences between clinical subgroups were evaluated using the Wilcoxon rank test.

RESULTS

The 2MWT# and 6MWT correlated highly (r = 83, 95% CI 0.76 - 0.87). The 2MWT# overestimated 6MWT results with 46.8 meters (SD 67.0). Both tests correlated with secondary outcomes and discriminated similarly between clinical subgroups.

CONCLUSIONS

The 2MWT# correlates highly with 6MWT but overestimates the observed 6MWT by 9%. Because it is shorter, possibly less burdensome, and with little or no loss of discriminatory ability, we consider it a legitimate alternative to the 6MWT in patients with LBP.Implications for rehabilitationWalking function is often affected in patients with low back pain (LBP).The six-minute walk test (6MWT) is frequently used to assess walking function but is time-consuming.A shorter two-minute walk test is a legitimate alternative in patients with LBP as it correlates highly with the 6MWT and has little or no loss of discriminatory ability between clinical subgroups.

An international consensus on gaps in mechanisms of forced-based manipulation research: findings from a nominal group technique

Force-Based Manipulation (FBM) including light touch, pressure, massage, mobilization, thrust manipulation, and needling techniques are utilized across several disciplines to provide clinical analgesia. These commonly used techniques demonstrate the ability to improve pain-related outcomes; however, mechanisms behind why analgesia occurs with these hands-on interventions has been understudied. Neurological, neuroimmune, biomechanical, neurovascular, neurotransmitter, and contextual factor interactions have been proposed to influence response; however, the specific relationships to clinical pain outcomes has not been well established. The purpose of this study was to identify gaps present within mechanism-based research as it relates to FBM. An international multidisciplinary nominal group technique (NGT) was performed and identified 37 proposed gaps across eight domains. Twenty-three of these gaps met consensus across domains supporting the complex multisystem mechanistic response to FBM. The strength of support for gaps within the biomechanical domain had less overall support than the others. Gaps assessing the influence of contextual factors had strong support as did those associating mechanisms with clinical outcomes (translational studies). The importance of literature investigating how FBM differs with individuals of different pain phenotypes (pain mechanism phenotypes and clinical phenotypes) was also presented aligning with other analgesic techniques trending toward patient-specific pain management (precision medicine) through the use of pain phenotyping.

Validation of a spring loaded probe for single and repeat pressure pain testing, including public domain specifications for design and manufacture

Temporal summation of pressure pain is technically more challenging than simple pressure pain thresholds. The current study describes the design, manufacture and validation of a simple mechanical test apparatus to assess the temporal summation of deep pressure pain. We release design details into the public domain with the intention of providing free access for researchers especially in low income countries. Utility and validity of the probes were assessed by pressure application in three different experimental setups: A. Identifying potential issues which needed to be addressed to ensure a reliable test procedure (189 tests with 24 testers using four different probes). B. Selecting the most reliable target force curve (one tester conducted 20 tests). C. Estimating classic inter and intra-examiner reliability and comparing probe measures to other QST measures (repeated measures study with counterbalancing). We make recommendations on best use of the probes. Pressure pain thresholds assessed using probes were affected by anatomical test site and testing tool, but not by tester, day or session. Temporal summation of pressure pain was significantly greater than that of a single pressure application. We found no correlation between temporal summation using the probes on the Infra-Spinatus muscle and temporal summation using a pneumatic cuff on the lower leg. The probe was a useful tool for assessing pain intensity and temporal summation of pressure pain intensity, but not for pain thresholds. A number of caveats need to be considered when using the probe, including but not limited to audio cues and target ideal wave function.

Patient and provider characteristics associated with therapeutic intervention selection in a chiropractic clinical encounter: a cross-sectional analysis of the COAST and O-COAST study data

BACKGROUND

Chiropractors use a variety of therapeutic interventions in clinical practice. How the selection of interventions differs across musculoskeletal regions or with different patient and provider characteristics is currently unclear. This study aimed to describe how frequently different interventions are used for patients presenting for chiropractic care, and patient and provider characteristics associated with intervention selection.

METHODS

Data were obtained from the Chiropractic Observation and Analysis STudy (COAST) and Ontario (O-COAST) studies: practice-based, cross-sectional studies in Victoria, Australia (2010-2012) and Ontario, Canada (2014-2015). Chiropractors recorded data on patient diagnosis and intervention selection from up to 100 consecutive patient visits. The frequency of interventions selected overall and for each diagnostic category (e.g., different musculoskeletal regions) were descriptively analysed. Univariable multi-level logistic regression (provider and patient as grouping factors), stratified by diagnostic category, was used to assess the association between patient/provider variables and intervention selection.

RESULTS

Ninety-four chiropractors, representative of chiropractors in Victoria and Ontario for age, sex, and years in practice, participated. Data were collected on 7,966 patient visits (6419 unique patients), including 10,731 individual diagnoses (mean age: 43.7 (SD: 20.7), 57.8% female). Differences in patient characteristics and intervention selection were observed between chiropractors practicing in Australia and Canada. Overall, manipulation was the most common intervention, selected in 63% (95%CI:62-63) of encounters. However, for musculoskeletal conditions presenting in the extremities only, soft tissue therapies were more commonly used (65%, 95%CI:62-68). Manipulation was less likely to be performed if the patient was female (OR:0.74, 95%CI:0.65-0.84), older (OR:0.79, 95%CI:0.77-0.82), presenting for an initial visit (OR:0.73, 95%CI:0.56-0.95) or new complaint (OR:0.82, 95%CI:0.71-0.95), had one or more comorbidities (OR:0.63, 95%CI:0.54-0.72), or was underweight (OR:0.47, 95%CI:0.35-0.63), or obese (OR:0.69, 95%CI:0.58-0.81). Chiropractors with more than five years clinical experience were less likely to provide advice/education (OR:0.37, 95%CI:0.16-0.87) and exercises (OR:0.17, 95%CI:0.06-0.44).

CONCLUSION

In more than 10,000 diagnostic encounters, manipulation was the most common therapeutic intervention for spine-related problems, whereas soft tissue therapies were more common for extremity problems. Different patient and provider characteristics were associated with intervention selection. These data may be used to support further research on appropriate selection of interventions for common musculoskeletal complaints.

No effect of social interaction on experimental pain sensitivity: a randomized experimental study

ABSTRACT

Quantitative sensory testing (QST) is a commonly applied paradigm to investigate pain, which is a subjective experience influenced by a myriad of social and contextual factors. Therefore, it is important to consider the potential sensitivity of QST to the test setting and the social interaction that naturally is a part of it. This may particularly be the case in clinical settings where patients have something at stake. Therefore, we investigated differences in pain responses using QST in different test setups with varying degrees of human interaction. In a parallel three-armed randomized experimental study, we included 92 participants with low back pain and 87 healthy volunteers allocated to 1 of the 3 QST setups: 1 setup with manual tests performed by a human tester, 1 setup with automated tests performed by a robot and orally guided by a human tester, and 1 setup with automated tests performed solely by a robot without social interaction with a human tester. All 3 setups consisted of the same pain tests in the same order, including pressure pain threshold and cold pressor tests. We found no statistically significant differences between setups on the primary outcome of conditioned pain modulation nor any secondary QST outcomes. While this study is not without limitations, the results indicate that QST procedures are robust enough not to be influenced by social interaction to an appreciable degree.

Spinal Manipulative Therapy for Nonspecific Low Back Pain: Does Targeting a Specific Vertebral Level Make a Difference?: A Systematic Review With Meta-analysis

OBJECTIVE: We aimed to examine whether targeting spinal manipulative therapy (SMT), by applying the intervention to a specific vertebral level, produces superior clinical outcomes than a nontargeted approach in patients with nonspecific low back pain. DESIGN: Systematic review with meta-analysis. LITERATURE SEARCH: MEDLINE, Embase, CENTRAL, CINAHL, Scopus, PEDro, and Index to Chiropractic Literature were searched up to May 31, 2023. STUDY SELECTION CRITERIA: Randomized controlled trials comparing targeted SMT (mobilization or manipulation) to a nontargeted approach in patients with nonspecific low back pain, and measuring the effects on pain intensity and patient-reported disability. DATA SYNTHESIS: Data extraction, risk of bias, and evaluation of the overall certainty of evidence using the GRADE approach were performed by 2 authors independently. Meta-analyses were performed using the restricted maximum likelihood method. RESULTS: Ten randomized controlled trials (n = 931 patients) were included. There was moderate-certainty evidence of no difference between targeted SMT and a nontargeted approach for pain intensity at postintervention (weighted mean difference = -0.20 [95% CI: -0.51, 0.10]) and at follow-up (weighted mean difference = 0.05 [95% CI: -0.26, 0.36]). For patient-reported disability, there was moderate-certainty evidence of no difference at postintervention (standardized mean difference = -0.04 [95% CI: -0.36, 0.29]) and at follow-up (standardized mean difference = -0.05 [95% CI: -0.24, 0.13]). Adverse events were reported in 4 trials, and were minor and evenly distributed between groups. CONCLUSION: Targeting a specific vertebral level when administering SMT for patients with nonspecific low back pain did not result in improved outcomes on pain intensity and patient-reported disability compared to a nontargeted approach. J Orthop Sports Phys Ther 2023;53(9):1-11. Epub: 28 July 2023. doi:10.2519/jospt.2023.11962.

Presenters at chiropractic research conferences 2010-2019: is there a gender equity problem?

BACKGROUND

Presenting at professional and scientific conferences can be an important part of an individual's career advancement, especially for researchers communicating scientific findings, and can signal expertise and leadership. Generally, women presenting at conferences are underrepresented in various science disciplines. We aimed to evaluate the gender of presenters at research-oriented chiropractic conferences from 2010 to 2019.

METHODS

We investigated the gender of presenters at conferences hosted by chiropractic organisations from 2010 to 2019 that utilised an abstract submission process. Gender classification was performed by two independent reviewers. The gender distribution of presenters over the ten-year period was analysed with linear regression. The association of conference factors with the gender distribution of presenters was also assessed with linear regression, including the gender of organising committees and abstract peer reviewers, and the geographic region where the conference was hosted.

RESULTS

From 39 conferences, we identified 4,340 unique presentations. Women gave 1,528 (35%) of the presentations. No presenters were classified as gender diverse. Overall, the proportion of women presenters was 30% in 2010 and 42% in 2019, with linear regression demonstrating a 1% increase in women presenting per year (95% CI = 0.4-1.6%). Invited/keynote speakers had the lowest proportion of women (21%) and the most stagnant trajectory over time. The gender of conference organisers and abstract peer reviewers were not significantly associated with the gender of presenters. Oceanic conferences had a lower proportion of women presenting compared to North America (27% vs. 36%).

CONCLUSIONS

Overall, women gave approximately one-third of presentations at the included conferences, which gradually increased from 2010 to 2019. However, the disparity widens for the most prestigious class of keynote/invited presenters. We make several recommendations to support the goal of gender equity, including monitoring and reporting on gender diversity at future conferences.

Do Visual Pain Trajectories Reflect the Actual Course of Low Back Pain? A Longitudinal Cohort Study

Different trajectories of low back pain (LBP) have been identified prospectively using repeated measures. For these trajectories to inform clinical practice, they must be available in the clinical consultation. Therefore, identified LBP trajectories have been translated into visual pain trajectories (VPTs) that allow people with LBP, at the time of consult, to reflect upon their pain experience and identify the VPT that best categorizes their pain course. We have limited knowledge regarding the extent to which a chosen VPT reflects the prospectively experienced trajectory. Thus, we explored the distribution of pain intensity and pain pattern characteristics (from prospective pain trajectory data) within the retrospectively chosen VPT classes. We enrolled patients with LBP from Danish chiropractic practice. Using SMS, participants (n = 719) scored their pain weekly on an 11-point numerical rating scale for 52 weeks. At week 52, participants identified 1 of 8 VPTs that reflected their perceived back pain trajectory during the preceding year. We found that the chosen VPTs reflected pain intensity, but that pain patterns (episodic, fluctuating, and persistent) were not systematically recognized, and the experienced course varied substantially amongst participants within the same VPT. The VPTs are related to some aspects of the experienced LBP course but are not a proxy for the SMS-measured trajectories. Reasons for apparent mismatches between the experienced course of LBP and VPT recall warrant further investigation. PERSPECTIVE: Self-reported back pain trajectories reflected pain intensities obtained through weekly SMS tracking over a year, but participants' recall did not reflect the pain patterns (episodes and fluctuations) discovered prospectively. Clinicians can use self-reported pain trajectories to facilitate a dialog about pain experience, but not as a proxy for prospective measures.

Multidisciplinary team-based management approach for secondary-care patients with severe and persistent low back pain: A mixed-method feasibility trial

BACKGROUND

Persistent and severe low back pain is challenging to treat. Multidisciplinary care with systematic follow-up may be more effective than usual care. However, such a model has yet to be developed and tested.

OBJECTIVE

Our objectives were to develop and test the feasibility of a three-month multidisciplinary intervention with systematic follow-up in a specialized hospital spine center for patients with severe and persistent low back pain.

METHODS

Using the Medical Research Council and National Institute for Health and Care Research framework for the development and testing of complex interventions, we developed a multidisciplinary intervention with systematic follow-up and tested its feasibility, using a-priori-determined outcomes during three months for 24 patients seen at a regional diagnostic spine center unit. As part of the evaluation, we conducted semi-structured interviews with participants and a focus-group interview with clinicians.

RESULTS

Of the 24 patients included, only 17 completed the course of care and provided complete data for feasibility assessment. We failed to reach our a-priori feasibility outcomes, had difficulty with inclusion, and participants did not find the intervention effective or satisfactory.

CONCLUSIONS

The intervention was not feasible as barriers existed on multiple levels (e.g., clinical, administrative, and patient). Excessive study moderations must be made before the intervention is feasible in a randomized trial.

A two-year follow-up: Twitter activity regarding misinformation about spinal manipulation, chiropractic care and boosting immunity during the COVID-19 pandemic

BACKGROUND

Spinal manipulative therapy (SMT) is offered by many health professions, most often by chiropractors. While SMT can be effective for some musculoskeletal disorders, there is no evidence that SMT improves human immunity in a clinically meaningful way. Despite this, we showed previously that Twitter misinformation about chiropractic/SMT  improving immunity increased sharply at the start of the COVID-19 pandemic. Here, we perform a two-year follow-up.

METHODS

We previously employed specialized software (i.e. Talkwalker) to search the entirety of Twitter activity in the  months before and after the COVID-19 pandemic was declared (March 11, 2020). In this paper, we conducted follow-up searches over two successive 12 month periods using terms related to SMT, immunity and chiropractic. The resulting tweets were then coded into those promoting/refuting a relation between SMT and immunity (tone) and messaging about chiropractic/interventions (content). Further analyses were performed to subcategorize tweet content, tally likes, retweets and followers, and evaluate refuting tweets and the country of origin. Finally, we created a chronology of Twitter activity superimposed with dates of promoting or refuting activities undertaken by chiropractic organizations.

RESULTS

Over the 27 month study period, Twitter activity peaked on March 31, 2020 then declined continuously. As in our first paper, our follow-up data showed that (1) the ratio of refuting/promoting tweets remained constant and (2) tweets that refuted a relationship between SMT and immunity were substantially more liked, retweeted and followed than those promoting. We also observed that promoting tweets suggesting that SMT improves immunity decreased more rapidly. Overwhelmingly, promoting tweets originated in the USA while refuting tweets originated in Canada, Europe and Australia. The timing of the decline in peak Twitter activity, together with a parallel decline in tweets claiming that SMT improves immunity, was coincident with initiatives by chiropractic organizations and regulators targeting misinformation.

CONCLUSION

Overwhelmingly, Twitter activity during the COVID-19 pandemic focussed on refuting a relation between chiropractic/SMT and immunity. A decline in Twitter activity promoting a relation between SMT and immunity was observed to coincide with initiatives from chiropractic organizations and regulators to refute these claims. The majority of misinformation about this topic is generated in the United States.

Database coverage and their use in systematic reviews regarding spinal manipulative therapy: an exploratory study

BACKGROUND

Systematic reviews (SRs) of randomized controlled trials (RCTs) are considered one of the most reliable study types. Through a systematic and thorough literature search, researchers aim to collect all research relevant to their purpose. The selection of databases can be challenging and depend on the topic of interest. The Cochrane Handbook suggests searching at least the following three databases: Cochrane Library, MEDLINE, and EMBASE. However, this is not always sufficient for reviews on the musculoskeletal field in general. This study aimed to examine the frequency and choice of databases used by researchers in SRs of spinal manipulative therapy (SMT). Secondly, to analyze the RCTs included in the SRs to determine the optimal combination of databases needed to conduct efficient literature searches for SRs of SMT.

METHODS

SRs investigating the effect of SMT on any patient-reported outcome measure were identified through searches in PubMed and Epistemonikos (all entries till date of search February 25, 2022). For each SR, databases searched and included RCTs were collected. RCTs were searched individually in nine databases (Cochrane Library, MEDLINE/PubMed, EMBASE, Google Scholar, CINAHL, Web of Science, Index to Chiropractic Literature, PEDro, and AMED). Coverage rates were calculated using the number of retrieved RCTs by the database or combinations of databases divided by the total number of RCTs.

RESULTS

Eighty-five SRs published met the inclusion criteria, and 442 unique RCTs were retrieved. The most frequently searched database was MEDLINE/PubMed. Cochrane Library had the highest overall coverage rate and contained the third most unique RCTs. While a 100% retrieval was not possible, as 18 RCTs could not be retrieved in any of the nine databases, the combination of Cochrane Library, Google Scholar, and PEDro retrieved all possible RCTs with a combined coverage rate of 95.9%.

CONCLUSIONS

For SRs on SMT, we recommend using the combination suggested by the Cochrane Handbook of Cochrane Library, MEDLINE/PubMed, Embase, and in addition, PEDro and Index to Chiropractic Literature. Google Scholar might be used additionally as a tool for searching gray literature and quality assurance.

Temporal stability of self-reported visual back pain trajectories

ABSTRACT

Low back pain (LBP) follows different pain trajectories, and patients seem to recognize their trajectory. This allows self-reported visual pain trajectories (SRVTs) to support patient-provider communication. Pain trajectories appear stable over time for many patients, but the evidence is sparse. Our objectives were to investigate the (1) temporal stability of SRVTs over 1 year concerning pain intensity and course patterns and (2) association of transitions between SRVTs and changes in pain and disability. This study used data from 2 prospective primary care cohorts: the Danish Chiropractic LBP Cohort (n = 1323) and the GLA:D Back cohort (n = 1135). Participants identified one of the 8 SRVTs at baseline and 12-month follow-up, each asking about LBP trajectories the preceding year. Trajectories were described using 2 subscales (intensity and pattern). Temporal stability was quantified by "stability odds ratios" (ORs), depicting the likelihood of staying in the same SRVT after 12 months compared with baseline, and by "preference ORs," depicting the likelihood of choosing a specific alternative SRVT at follow-up. Both ORs compare the observed proportion with the chance level. Finally, we examined associations between transitioning to a different trajectory and changes in clinical outcomes. Approximately 30% stayed in the same SRVT. The stability ORs were all >1. The preference ORs indicated that transitions occurred mainly to similar SRVTs differing in only 1 subscale. Transitions to less or more intense SRVTs were associated with changes in clinical outcomes in the expected direction. Despite distinctly different SRVTs identified, individuals reported relatively stable LBP phenotypes but with potential for change.

"Convergent validity of the central sensitization inventory and experimental testing of pain sensitivity"

OBJECTIVES

The aim of the current study was to examine the convergent validity of the Central Sensitization Inventory by quantifying the correlation with experimental measures of pain sensitivity and self-reported psycho-social questionnaires, in a low back pain population.

METHODS

All participants were recruited from an outpatient hospital spine care clinic (Spine Centre of Southern Denmark). Participants underwent a standardized experimental pain test protocol and completed the Central Sensitization Inventory (CSI) along with additional self-reported questionnaires to assess psycho-social constructs across different domains. The association between the CSI, experimental pain measures and other self-reported psycho-social questionnaires were analyzed using correlation and contingency tests. ROC-curve analysis was used to determine sensitivity and specificity for CSI.

RESULTS

One hundred sixty-eight (168) participants were included. The CSI was weakly correlated with nine out of 20 variables in the experimental pain test protocol (rho range -0.37 to 0.22). The CSI was more closely correlated with psycho-social factors such as work ability, disability, and symptoms of exhaustion disorder. ROC-analysis identified an optimal cut-point of 44 on CSI (Sn=39.1% Sp=87.4%). The CSI had an area under the ROC curve of 0.656. Fisher's exact test demonstrated a statistically significant association between participants scoring ≥40 on CSI and participants categorized as sensitized by experimental pain tests (p-value=0.03).

CONCLUSIONS

Our findings are consistent with previous studies, indicating that the CSI is related to psycho-social constructs. However, the convergent validity with experimental pain measures is small and probably not clinically meaningful.

A cross-sectional analysis of persistent low back pain, using correlations between lumbar stiffness, pressure pain threshold, and heat pain threshold

Introduction

Little is known about the underlying biomechanical cause of low back pain (LBP). Recently, technological advances have made it possible to quantify biomechanical and neurophysiological measurements, potentially relevant factors in understanding LBP etiology. However, few studies have explored the relation between these factors. This study aims to quantify the correlation between biomechanical and neurophysiological outcomes in non-specific LBP and examine whether these correlations differ when considered regionally vs. segmentally.

Methods

This is a secondary cross-sectional analysis of 132 participants with persistent non-specific LBP. Biomechanical data included spinal stiffness (global stiffness) measured by a rolling indenter. Neurophysiological data included pain sensitivity (pressure pain threshold and heat pain threshold) measured by a pressure algometer and a thermode. Correlations were tested using Pearson’s product-moment correlation or Spearman’s rank correlation as appropriate. The association between these outcomes and the segmental level was tested using ANOVA with post-hoc Tukey corrected comparisons.

Results

A moderate positive correlation was found between spinal stiffness and pressure pain threshold, i.e., high degrees of stiffness were associated with high pressure pain thresholds. The correlation between spinal stiffness and heat pain threshold was poor and not statistically significant. Aside from a statistically significant minor association between the lower and the upper lumbar segments and stiffness, no other segmental relation was shown.

Conclusions

The moderate correlation between spinal stiffness and mechanical pain sensitivity was the opposite of expected, meaning higher degrees of stiffness was associated with higher pressure pain thresholds. No clinically relevant segmental association existed.

Posterior to anterior spinal stiffness measured in a sample of 127 secondary care low back pain patients

BACKGROUND

The sensation of spinal stiffness is a commonly reported symptom among back pain patients, with the clinical assessment of spinal stiffness usually being part of the decision-making process when deciding on providing manual treatment of low back pain. While any relationship between spinal stiffness and low back pain is likely to be multifactorial, prior exploration of this relationship has been overly simplistic (e.g., univariate regression analyses). The purpose of this study was to address this gap by taking a broader approach to compare instrumented measures of spinal stiffness to demographic characteristics, pain phenotypes, psychometrics, and spine-related disability in a sample of secondary care low back pain patients using multivariate regression analysis.

METHODS

Instrumented spinal stiffness measures from 127 patients in secondary care were used to calculate terminal and global spinal stiffness scores. A best subset analysis was used to find the subsets of 14 independent variables that most accurately predicted stiffness based on the evaluation of the adjusted R-square, Akaike Information Criteria, and the Bayesian Information Criteria.

FINDINGS

In the resulting multivariate models, sex (p < 0.001) and age (p < 0.001) were the primary determinants of terminal stiffness, while global stiffness was primarily determined by age (p = 0.003) and disability (p = 0.024).

INTERPRETATION

Instrumented measures of spinal stiffness are multifactorial in nature, and future research into this area should make use of multivariate analyses.

The inhibitory effect of conditioned pain modulation on temporal summation in low-back pain patients

OBJECTIVES

The literature on conditioned pain modulation (CPM) is inconclusive in relation to low-back pain and it is unclear how CPM affects temporal summation as a proxy of central pain integration. The aim of this study was to examine whether the CPM effect would be different on pain induced by temporal summation than single stimuli in a group of low back pain patients.

METHODS

A total of 149 low-back pain patients were included. CPM was examined using single, repeated and temporal summation (repeated-single difference) of mechanical pressure pain as test stimuli at an individualized, fixed supra-pain-threshold force, before and after 2 min of cold pressor test (0-2 degrees Celsius). Participants were categorized as CPM responders or non-responders according to three different criteria: simple (any pain inhibition), strict (pain inhibition of more than 10VAS) and reversed (pain inhibition or facilitation of less than 10VAS). Clinical data on back pain was collected for correlation and descriptive purposes.

RESULTS

Significant modulation was observed for all three test stimuli. Effects sizes were comparable in relative terms, but repeated pressure pain modulation was greater in absolute terms. No correlations to clinical data were observed, for any measure.

CONCLUSIONS

The current data suggests that repeated pressure pain may be better suited as the CPM test stimuli, than single pressure pain and temporal summation of pressure pain, as the CPM effect in absolute terms was greater. Employing temporal summation as the test stimulus in a CPM paradigm may be more sensitive than a single test stimulus.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

TRIAL REGISTRATION

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

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

Background

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

Methods

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

Results

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

Conclusion

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

Trial registration

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

Supplementary Information

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

Self-reports vs. physical measures of spinal stiffness

Background

Objectively measured reduction in lumbar posterior-to-anterior (PA) stiffness is associated with pain relief in some, but not all persons with low back pain. Unfortunately, these measurements can be time consuming to perform. In comparison, the Lumbar Spine Instability Questionnaire (LSIQ) is intended to measure spinal instability and the Lumbar Spine Disability Index (LSDI) is created for self-reporting functional disability due to increased spinal stiffness. Given the above, the aim of this study is to compare measures of the LSIQ and LSDI with objective measures of lumbar PA stiffness as measured by a mechanical device, Vertetrack (VT), in patients with persistent non-specific low back pain (nsLBP).

Methods

Twenty-nine patients with nsLBP completed the LSIQ and LSDI at baseline and after two weeks. On these same occasions, PA spinal stiffness was measured using the VT. Between measurements, patients received four sessions of spinal manipulation. The resulting data was analyzed to determine the correlation between the self-report and objective measures of stiffness at both time points. Further, the patients were categorized into responders and non-responders based on pre-established cut points depending on values from the VT and compared those to self-report measures in order to determine whether the LSIQ and the LSDI were sensitive to change.

Results

Twenty-nine participants completed the study. Measures from the LSIQ and LSDI correlated poorly with objectively measured lumbar PA stiffness at baseline and also with the change scores. The change in objectively measured lumbar PA stiffness following spinal manipulation did not differ between those who improved, and those who did not improve according to the pre-specified cut-points. Finally, a reduction in lumbar PA stiffness following intervention was not associated with improvement in LSIQ and LSDI outcomes.

Conclusions

The current data indicate that the LSIQ and LSDI questionnaires do not correlate with measures obtained objectively by VT. Our results suggest that these objective and self- reported measures represent different domains and as such, cannot stand in place of one another.

Chiropractic conservatism among chiropractic students in Denmark: prevalence and consequences

Background

The chiropractic profession is split between those practicing evidence-based and those whose practice is honed by vitalism. The latter has been coined ‘chiropractic conservatism’. In Denmark, the chiropractic education program is university-based in close collaboration with a medical faculty. We wanted to investigate if such conservative attitudes were present in this environment.

Our objectives were to i) determine the level of chiropractic conservatism, ii) investigate if this was linked to academic year of study, iii) determine the level of clinical appropriateness, and iv) to investigate if this was affected by the level of conservatism among students in a chiropractic program, where the students are taught alongside medical students at the University of Southern Denmark (SDU).

Methods

A cross-sectional survey of 146 (response-rate 76%) 3rd to 5th year pre-graduate students and 1st year postgraduate clinical interns from the chiropractic degree course at the University of Southern Denmark was conducted during autumn of 2019. The students’ levels of conservatism were dichotomized into appropriate/inappropriate, summed up, and used in a linear regression model to determine the association with academic year of study. Thereafter, the conservatism score was categorized into four groups (from low -1- to high -4-). Conservatism groups were cross-tabulated with the ability to answer appropriately on nine cases concerning i) contra-indications, ii) non-indications, and iii) indications for spinal manipulation and analyzed using logistic regression.

Results

Generally, the Danish chiropractic students had low conservatism scores, decreasing with increasing academic year of study. Seventy percent of the students were placed in the two lowest conservative groups. The level of conservatism (categories 1–3) was moderately (but not statistically significantly) associated with an inability to recognize non-indications to treatment. Three outliers (category 4), however, revealed a highly inappropriate handling of the clinical cases.

Conclusions

Chiropractic students enrolled at a university-based course closely integrated with a medical teaching environment are not immune to chiropractic conservatism. However, the course appears to attenuate it and limit its effect on clinical decision-making compared to other educational institutions.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12998-020-00352-3.

Misinformation, chiropractic, and the COVID-19 pandemic

BACKGROUND

In March 2020, the World Health Organization elevated the coronavirus disease (COVID-19) epidemic to a pandemic and called for urgent and aggressive action worldwide. Public health experts have communicated clear and emphatic strategies to prevent the spread of COVID-19. Hygiene rules and social distancing practices have been implemented by entire populations, including 'stay-at-home' orders in many countries. The long-term health and economic consequences of the COVID-19 pandemic are not yet known.

MAIN TEXT

During this time of crisis, some chiropractors made claims on social media that chiropractic treatment can prevent or impact COVID-19. The rationale for these claims is that spinal manipulation can impact the nervous system and thus improve immunity. These beliefs often stem from nineteenth-century chiropractic concepts. We are aware of no clinically relevant scientific evidence to support such statements. We explored the internet and social media to collect examples of misinformation from Europe, North America, Australia and New Zealand regarding the impact of chiropractic treatment on immune function. We discuss the potential harm resulting from these claims and explore the role of chiropractors, teaching institutions, accrediting agencies, and legislative bodies.

CONCLUSIONS

Members of the chiropractic profession share a collective responsibility to act in the best interests of patients and public health. We hope that all chiropractic stakeholders will view the COVID-19 pandemic as a call to action to eliminate the unethical and potentially dangerous claims made by chiropractors who practise outside the boundaries of scientific evidence.

The effect on clinical outcomes when targeting spinal manipulation at stiffness or pain sensitivity: a randomized trial

The mechanisms underlying pain relief following spinal manipulative therapy (SMT) are not understood fully although biomechanical and neurophysiological processes have been proposed. As such, we designed this randomized trial to elucidate the contributions of biomechanical and neurophysiological processes. A total of 132 participants with low back pain were randomly assigned to receive SMT at either the lumbar segment measured as the stiffest or the segment measured as having the lowest pain threshold. The primary outcome was patient reported low back pain intensity following treatment. Secondary outcomes were biomechanical stiffness and neurophysiological pressure pain threshold. All outcomes were measured at baseline, after the fourth and final session and at 2-weeks follow-up. Data were analyzed using linear mixed models, and demonstrated that the SMT application site did not influence patient reported low back pain intensity or stiffness. However, a large and significant difference in pressure pain threshold was observed between groups. This study provides support that SMT impacts neurophysiological parameters through a segment-dependent neurological reflex pathway, although this do not seem to be a proxy for improvement. This study was limited by the assumption that the applied treatment was sufficient to impact the primary outcome.

Misinformation about spinal manipulation and boosting immunity: an analysis of Twitter activity during the COVID-19 crisis

Background

Social media has become an increasingly important tool in monitoring the onset and spread of infectious diseases globally as well monitoring the spread of information about those diseases. This includes the spread of misinformation, which has been documented within the context of the emerging COVID-19 crisis. Understanding the creation, spread and uptake of social media misinformation is of critical importance to public safety. In this descriptive study, we detail Twitter activity regarding spinal manipulative therapy (SMT) and claims it increases, or “boosts”, immunity. Spinal manipulation is a common intervention used by many health professions, most commonly by chiropractors. There is no clinical evidence that SMT improves human immunity.

Methods

Social media searching software (Talkwalker Quick Search) was used to describe Twitter activity regarding SMT and improving or boosting immunity. Searches were performed for the 3 months and 12 months before March 31, 2020 using terms related to 1) SMT, 2) the professions that most often provide SMT and 3) immunity. From these searches, we determined the magnitude and time course of Twitter activity then coded this activity into content that promoted or refuted a SMT/immunity link. Content themes, high-influence users and user demographics were then stratified as either promoting or refuting this linkage.

Results

Twitter misinformation regarding a SMT/immunity link increased dramatically during the onset of the COVID crisis. Activity levels (number of tweets) and engagement scores (likes + retweets) were roughly equal between content promoting or refuting a SMT/immunity link, however, the potential reach (audience) of tweets refuting a SMT/immunity link was 3 times higher than those promoting a link. Users with the greatest influence on Twitter, as either promoters or refuters, were individuals, not institutions or organizations. The majority of tweets promoting a SMT/immunity link were generated in the USA while the majority of refuting tweets originated from Canada.

Conclusion

Twitter activity about SMT and immunity increased during the COVID-19 crisis. Results from this work have the potential to help policy makers and others understand the impact of SMT misinformation and devise strategies to mitigate its impact.

Managing sickness absence of patients with musculoskeletal pain - a cross-sectional survey of Scandinavian chiropractors

Background

Musculoskeletal pain is a major cause of work disability. Many patients with musculoskeletal pain seek care from health care providers other than their general practitioners, including a range of musculoskeletal practitioners. Therefore, these musculoskeletal practitioners may play a key role by engaging in sickness absence management and work disability prevention. This study aimed to determine the prevalence of musculoskeletal practitioners’ practice behaviours, and their perceptions and beliefs about sickness absence management by using Scandinavian chiropractors as an example, as well as to examine the association between these characteristics and two different practice behaviours.

Methods

As part of a mixed-methods study, we surveyed members of the national chiropractic associations in Denmark, Norway, and Sweden in 2016. Descriptive statistics were used to describe prevalence. Multilevel logistic regression with backwards stepping was used to estimate odds ratios with 95% confidence intervals between each of the two practice behaviours and the characteristics.

Results

Out of the 802 respondents (response rate 56%), 372 were Danish, 349 Norwegian, and 81 Swedish. In Denmark and Norway, 38.7 and 37.8% always/often considered if sick leave was appropriate for their patient compared to 21.0% in Sweden (p = 0.007); and 86.5% of the Norwegian chiropractors always/often recommended to return-to-work versus 64.5 and 66.7% in Denmark and Sweden respectively (p < 0.001). In the final models, factors associated with the two practice behaviours were age, level of clinical experience, working as a teacher, the tendency to be updated on current legislations and policies using social services, contact with general practitioners, relevance of engagement in SAM, consideration of workplace factors, SAM as part of the clinical tool box, patient out-of-pocket fee, and recommending fast return-to-work.

Conclusions

Whilst not always engaged in sickness absence management with regards to musculoskeletal pain, chiropractors favour a ‘return-to-work’ rather than a ‘stay-at-home’ approach. Several practice behaviours and perceptions and beliefs are associated with these outcomes; however, system or organisational barriers are linked to clinician non-engagement.

Electronic supplementary material

The online version of this article (10.1186/s12998-018-0230-y) contains supplementary material, which is available to authorized users.

Can chiropractors contribute to work disability prevention through sickness absence management for musculoskeletal disorders? - a comparative qualitative case study in the Scandinavian context

Background

Despite extensive publication of clinical guidelines on how to manage musculoskeletal pain and back pain in particular, these efforts have not significantly translated into decreases in work disability due to musculoskeletal pain. Previous studies have indicated a potential for better outcomes by formalized, early referral to allied healthcare providers familiar with occupational health issues. Instances where allied healthcare providers of comparable professional characteristics, but with differing practice parameters, can highlight important social and organisational strategies useful for informing policy and practice. Currently, Norwegian chiropractors have legislated sickness certification rights, whereas their Danish and Swedish counterparts do not. Against the backdrop of legislative variation, we described, compared and contrasted the views and experiences of Scandinavian chiropractors engaging in work disability prevention and sickness absence management.

Methods

This study was embedded in a two-phased, sequential exploratory mixed-methods design. In a comparative qualitative case study design, we explored the experience of chiropractors regarding sickness absence management drawn from face-to-face, semi-structured interviews. We subsequently coded and thematically restructured their experiences and perceptions.

Results

Twelve interviews were conducted. Thematically, chiropractors' capacity to support patients in sickness absence management revolved around four key issues: issues of legislation and politics; the rationale for being a sickness absence management partner; whether an integrated sickness absence management pathway existed/could be created; and finally, the barriers to service provision for sickness absence management.

Conclusion

Allied health providers, in this instance chiropractors, with patient management expertise can fulfil a key role in sickness absence management and by extension work disability prevention when these practices are legislatively supported. In cases where these practices occur informally, however, practitioners face systemic-related issues and professional self-image challenges that tend to hamper them in fulfilling a more integrated role as providers of work disability prevention practices.