Trends of Low Back Pain Research in Older and Working-Age Adults from 1993 to 2023: A Bibliometric Analysis.

Although the number of publications focusing on low back pain in older adults (LBP-O) and working-age adults (LBP-W) has been growing for decades, comparative research trends in these two populations, which may help to guide future investigation, have not been rigorously explored. This analysis aimed to describe publication patterns and trends of research targeting LBP-O and LBP-W over the last three decades. Peer-reviewed LBP-O and LBP-W articles published between 1993 and 2023 were retrieved from the Web of Science, which provided the details of annual publication volume, and prominent journals/countries/institutions. The relationship between the annual publication volumes and years was analyzed by Spearman correlation analysis. The hot topics and emerging trends were analyzed by VOSviewer and CiteSpace, respectively. A total of 4217 LBP-O-related and 50,559 LBP-W-related documents were included. The annual publication volumes of LBP-O and LBP-W articles increased over the years (r=0.995 to 0.998, p<0.001). The United States had the highest number of prominent institutions publishing relevant articles. The most prolific journal for LBP-O (5.4%) and LBP-W-related (6.1%) papers is the journal "Spine". Cognitive behavioral therapy, intervertebral disc (IVD) degeneration, physiotherapy, physical activity, and walking were the recent hot topics and physical activity was an emerging trend in LBP-O, while surgery and IVD degeneration (also a hot topic) were emerging trends in LBP-W. This study highlights the paucity of LBP-O-related research in the past. The United States and the journal Spine stand out in LBP research. The research trend of physical activity in LBP-O is consistent with the recognized importance of physical activity for older adults in general, and for managing LBP-O in particular. Conversely, the emerging trends of surgery and intervertebral disc degeneration in LBP-W research highlight a focus on the biomedical model of LBP despite LBP being a biopsychosocial condition.

"I Want People to Be Able to Make an Informed Choice": How Quebec naturopaths discuss vaccination in their practice.

Health care providers' recommendations can play an important role in individuals' vaccination decisions. Despite being one of the most popular complementary and alternative medicine (CAM), naturopathy is understudied in relation to vaccination decisions. We sought to address this gap through this study of vaccination perspectives of naturopathy practitioners in the province of Quebec, Canada. We conducted in-depth interviews with 30 naturopaths. Thematic analysis was conducted. Main themes were developed deductively (i.e., based on prior literature) and expanded through inductive coding of the data. Participants noted that they discuss vaccination in their practice, but only when clients asked questions or wanted advice. Naturopaths described refraining from explicitly recommending for or against vaccination. Instead, they focus on empowering their clients to make their own informed decision regarding vaccination. Most participants noted that they direct clients towards sources of information so that clients could decide for themselves, but some mentioned they discussed with clients what they considered to be risks associated with vaccination, as well as its benefits. These discussions were framed through a personalized and individual approach with clients.

Algorithm for Schroth-Curve-Type Classification of Adolescent Idiopathic Scoliosis: An Intra- and Inter-Rater Reliability Study.

Schroth exercises for scoliosis are prescribed based on curve types. This study aimed to determine the reliability of an algorithm for classifying Schroth curve types. Forty-four consecutive volunteers with adolescent idiopathic scoliosis, 10 to 18 years old, with curves 10° to 50°, were recruited from a scoliosis clinic. Their standing posture and Adam's bending test were videotaped. Ten consecutive Schroth therapist volunteers from an international registry independently classified the curve types using the proposed classification algorithm. Videos were rated twice at least seven days apart. Reliability was calculated using the Gwet's AC1 agreement coefficient for all the raters and for subgroups reporting full understanding (well-trained) and with prior algorithm experience. The intra-rater and weighted agreement coefficients for all the raters were 0.64 (95% CI: 0.53-0.73) and 0.75 (0.63-0.84), respectively. For the well-trained raters, they were 0.70 (0.60-0.78) and 0.82 (0.73-0.88), respectively; for the experienced raters, they were 0.81 (0.77-0.85) and 0.89 (0.80-0.94), respectively. The inter-rater versus weighted agreement coefficients for all the raters were 0.43 (0.28-0.58) versus 0.48 (0.29-0.67). For the well-trained raters, they were 0.50 (0.38-0.61) versus 0.61 (0.49-0.72), and for the experienced raters, they were 0.67 (0.50-0.85) versus 0.79 (0.64-0.94). Full understanding and experience led to higher reliability. Use of the algorithm can help standardize Schroth exercise treatment.

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.

Consensus for Statements Regarding a Definition for Spinal Osteoarthritis for Use in Research and Clinical Practice: A Delphi Study.

OBJECTIVE: To determine consensus among an international, multidisciplinary group of experts regarding definitions of spinal osteoarthritis for research and for clinical practice. METHODS: A 15-member, multidisciplinary steering committee generated 117 statements for a 3-round Delphi study. Experts in back pain and/or osteoarthritis were identified and invited to participate. In round 1, participants could propose additional statements for voting. All statements were rated on a 1-9 Likert scale, and consensus was set at ≥70% of respondents agreeing or disagreeing with the statement and <15% of respondents providing the opposite response. RESULTS: In total, 255 experts from 11 different professional backgrounds were invited. From 173 available experts, 116 consented to participate. In round 1, 103 participants completed the survey, followed by 85 of 111 participants in round 2 (77%) and 87 of 101 participants in round 3 (86%). One-third of participants were from Europe (30%), most were male (58%), one-fifth were physical therapists (21%), and over one-third had been in their profession for 11-20 years (35%). Of 131 statements, consensus was achieved for 71 statements (54%): 53 in agreement (75%) and 18 in disagreement (25%). CONCLUSION: Although there was consensus for statements for definitions of spinal osteoarthritis that were analogous to definitions of osteoarthritis in appendicular joints, a future definition still needs refinement. Importantly, this Delphi highlighted that a future definition should be considered across a spectrum of structural changes and patient symptoms and expressed on a progressive scale.

An exploratory study to understand how people use Twitter to share experiences or information about spinal stenosis.

BACKGROUND: Spinal stenosis is a narrowing of the spinal canal that may compress neurological tissues resulting in pain and disability. Although previous qualitative studies have solicited data regarding the life experience of patients with spinal stenosis or their opinions on relevant non-surgical treatments, their data was collected from participants in a controlled setting. Therefore, it remains unclear whether patients' or caregivers' concerns/opinions about spinal stenosis would be different in a non-experimental environment. Since Twitter is a popular online platform for people to share information and interact, it may reveal people's thoughts and attitudes about spinal stenosis. This study aimed to identify tweets that are related to spinal stenosis on Twitter, and to categorize them into common themes. METHODS: A social media monitoring and analysis software program (TalkWalker) was used to search relevant tweets using the keywords 'spinal stenosis' and 'stenosis' between 29 May 2019 and 24 June 2020. Two independent reviewers screened and conducted content analysis of the tweets and classified the tweets into different themes. RESULTS: Of 510 identified tweets, 362 tweets met the selection criteria. Five themes were identified: (1) compromised physical, psychological, and social wellbeing (n = 173); (2) diverse treatment options (n = 69); (3) coping strategies (n = 30); (4) dissemination of scientific information (n = 86); and (5) health policy (n = 4). Most of the tweets revealed negative impacts of spinal stenosis on patients' physical and psychosocial wellbeing. People with spinal stenosis shared their experiences and sought helps from others, while some people used Twitter to disseminate relevant information and research findings. CONCLUSIONS: This is the first study exploring Twitter using an online analytical tool to identify themes related to spinal stenosis. The approach not only helps understand people's concerns about spinal stenosis in an uncontrolled environment, but also can be adopted to monitor influences of diseases or public health education on Twitter users.

Research Priorities of the Australian Chiropractic Profession: A Cross-Sectional Survey of Academics and Practitioners.

OBJECTIVE: The purpose of this study was to explore the research priorities of Australian practicing chiropractors and academics across a set of research domains to determine the agreement or disagreement based on these domains. METHODS: We conducted a pilot-tested online survey focusing on the following 5 principal research domains: basic science, conditions (disorders chiropractors may encounter), patient subgroups, clinical interventions, and practice and public health/health services. Responses were sought regarding support for funding research scholarships, practice-based research networks, scientific conferences/symposia, journals, and existing research agendas. Data were collected (February 19 to May 24, 2019) from a sample of chiropractic academics (n1 = 33) representing 4 Australian programs and practicing chiropractors (n2 = 340). Collected data were ranked and analyzed to determine agreement across domains and items. RESULTS: There was agreement between the 2 groups across the majority (>90%) of domain items. The closest agreement and highest rankings were achieved for the "clinical interventions and practice" and "conditions" domains. Disagreement was observed within specific domain items, such as patient subgroups (infants), and for 1 intervention (chiropractic-specific techniques). Disagreement also occurred outside of the main domains, including research agenda support and funding. CONCLUSIONS: There was overall agreement between practicing chiropractors and academics across most research area domain items, which should help facilitate consensus-led development of any potential Australian Chiropractic research agenda. Disagreements across specific domain items, such as population subgroups, interventions, and funding require further investigation.

A prospective study of patients with low back pain attending a Canadian emergency department: Why they came and what happened?

Low back pain is a common presentation to emergency departments, but the reasons why people choose to attend the emergency department have not been explored. We aimed to fill this gap with this study to understand why persons with low back pain choose to attend the emergency department. Between July 4, 2017 and October 1, 2018, consecutive patients with a complaint of low back pain presenting to the University of Alberta Hospital emergency department were screened. Those enrolled completed a 13-item questionnaire to assess reasons and expectations related to their presentation. Demographics, acuity and disposition were obtained electronically. Factors associated with admission were examined in a logistic regression model. After screening 812 patients, 209 participants met the study criteria. The most common Canadian Triage and Acuity Scale score was 3 (73.2%). Overall, 37 (17.7%) received at least one consultation, 89.0% of participants were discharged home, 9.6% were admitted and 1.4% were transferred. Participants had a median pain intensity of 8/10 and a median daily functioning of 3/10. When asked, 64.6% attended for pain control while 44.5% stated ease of access. Most participants expected to obtain pain medication (67%) and advice (56%). Few attended because of cost savings (3.8%). After adjustment, only advanced age and ambulance arrival were significantly associated with admission. In conclusion, most low back pain patients came to the emergency department for pain control yet few were admitted and the majority did not receive a consultation. Timely alternatives for management of low back pain in the emergency department appear needed, yet are lacking.

The importance of selecting the correct site to apply spinal manipulation when treating spinal pain: Myth or reality? A systematic review.

The concept that spinal manipulation therapy (SMT) outcomes are optimized when the treatment is aimed at a clinically relevant joint is commonly assumed and central to teaching and clinical use (candidate sites). This systematic review investigated whether clinical effects are superior when this is the case compared to SMT applied elsewhere (non-candidate sites). Eligible study designs were randomized controlled trials that investigated the effect of spinal manipulation applied to candidate versus non-candidate sites for spinal pain. We obtained data from four different databases. Risk of bias was assessed using an adjusted Cochrane risk of bias tool, adding four items for study quality. We extracted between-group differences for any reported outcome or, when not reported, calculated effect sizes from the within-group changes. We compared outcomes for SMT applied at a 'relevant' site to SMT applied elsewhere. We prioritized methodologically robust studies when interpreting results. Ten studies, all of acceptable quality, were included that reported 33 between-group differences-five compared treatments within the same spinal region and five at different spinal regions. None of the nine studies with low or moderate risk of bias reported statistically significant between-group differences for any outcome. The tenth study reported a small effect on pain (1.2/10, 95%CI - 1.9 to - 0.5) but had a high risk of bias. None of the nine articles of low or moderate risk of bias and acceptable quality reported that "clinically-relevant" SMT has a superior outcome on any outcome compared to "not clinically-relevant" SMT. This finding contrasts with ideas held in educational programs and clinical practice that emphasize the importance of joint-specific application of SMT.

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.

Characterization of thoracic spinal manipulation and mobilization forces in older adults.

BACKGROUND: Spinal mobilization and spinal manipulation are common interventions used by manual therapists to treat musculoskeletal conditions in older adults. Their force-time characteristics applied to older adults' thoracic spine are important considerations for effectiveness and safety but remain unknown. This study aimed to describe the force-time characteristics of posterior-to-anterior spinal mobilization and manipulation delivered to older adults' thoracic spine. METHODS: Twenty-one older adults (≥65 years) with no thoracic pain received posterior-to-anterior thoracic spinal mobilization and/or manipulation with the force characteristics a chiropractor deemed appropriate. Six-degree-of-freedom load cells and an instrumented treatment table recorded the force characteristics of both interventions at the clinician-participant and participant-table interfaces, respectively. Preload force, total peak force, time to peak and loading rate were analyzed descriptively. FINDINGS: Based on data from 18 adults (56% female; average: 70 years old), mean resultant spinal mobilization forces at the clinician-participant interface were: 220 ± 51 N during preload, 323 ± 67 N total peak force, and 312 ± 38 ms time to peak. At the participant-table interface, mobilization forces were 201 ± 50 N during preload, 296 ± 63 N total peak force, and 308 ± 44 ms time to peak. Mean resultant spinal manipulation forces at the clinician-participant interface were: 260 ± 41 N during preload, 470 ± 46 N total peak force, and 165 ± 28 ms time to peak. At the participant table interface, spinal manipulation forces were 236 ± 47 N during preload, 463 ± 57 N total peak force, and 169 ± 28 ms time to peak. INTERPRETATION: Results suggest older adults experience unique, but comparable force-time characteristics during spinal mobilization and manipulation delivered to their thoracic spine compared to the ones delivered to younger adults described in the literature.

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.

Repetitive in vivo manual loading of the spine elicits cellular responses in porcine annuli fibrosi.

Back pain and intervertebral disc degeneration are prevalent, costly, and widely treated by manual therapies, yet the underlying causes of these diseases are indeterminate as are the scientific bases for such treatments. The present studies characterize the effects of repetitive in vivo manual loads on porcine intervertebral disc cell metabolism using RNA deep sequencing. A single session of repetitive manual loading applied to the lumbar spine induced both up- and down-regulation of a variety of genes transcribed by cells in the ventral annuli fibrosi. The effect of manual therapy at the level of loading was greater than at a level distant to the applied load. Gene ontology and molecular pathway analyses categorized biological, molecular, and cellular functions influenced by repetitive manual loading, with over-representation of membrane, transmembrane, and pericellular activities. Weighted Gene Co-expression Network Analysis discerned enrichment in genes in pathways of inflammation and skeletogenesis. The present studies support previous findings of intervertebral disc cell mechanotransduction, and are the first to report comprehensively on the repertoire of gene targets influenced by mechanical loads associated with manual therapy interventions. The present study defines the cellular response of repeated, low-amplitude loads on normal healthy annuli fibrosi and lays the foundation for future work defining how healthy and diseased intervertebral discs respond to single or low-frequency manual loads typical of those applied clinically.

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.

The global summit on the efficacy and effectiveness of spinal manipulative therapy for the prevention and treatment of non-musculoskeletal disorders: a systematic review of the literature.

BACKGROUND: A small proportion of chiropractors, osteopaths, and other manual medicine providers use spinal manipulative therapy (SMT) to manage non-musculoskeletal disorders. However, the efficacy and effectiveness of these interventions to prevent or treat non-musculoskeletal disorders remain controversial. OBJECTIVES: We convened a Global Summit of international scientists to conduct a systematic review of the literature to determine the efficacy and effectiveness of SMT for the primary, secondary and tertiary prevention of non-musculoskeletal disorders. GLOBAL SUMMIT: The Global Summit took place on September 14-15, 2019 in Toronto, Canada. It was attended by 50 researchers from 8 countries and 28 observers from 18 chiropractic organizations. At the summit, participants critically appraised the literature and synthesized the evidence. SYSTEMATIC REVIEW OF THE LITERATURE: We searched MEDLINE, Embase, the Cochrane Central Register of Controlled Trials, the Cumulative Index to Nursing and Allied Health, and the Index to Chiropractic Literature from inception to May 15, 2019 using subject headings specific to each database and free text words relevant to manipulation/manual therapy, effectiveness, prevention, treatment, and non-musculoskeletal disorders. Eligible for review were randomized controlled trials published in English. The methodological quality of eligible studies was assessed independently by reviewers using the Scottish Intercollegiate Guidelines Network (SIGN) criteria for randomized controlled trials. We synthesized the evidence from articles with high or acceptable methodological quality according to the Synthesis without Meta-Analysis (SWiM) Guideline. The final risk of bias and evidence tables were reviewed by researchers who attended the Global Summit and 75% (38/50) had to approve the content to reach consensus. RESULTS: We retrieved 4997 citations, removed 1123 duplicates and screened 3874 citations. Of those, the eligibility of 32 articles was evaluated at the Global Summit and 16 articles were included in our systematic review. Our synthesis included six randomized controlled trials with acceptable or high methodological quality (reported in seven articles). These trials investigated the efficacy or effectiveness of SMT for the management of infantile colic, childhood asthma, hypertension, primary dysmenorrhea, and migraine. None of the trials evaluated the effectiveness of SMT in preventing the occurrence of non-musculoskeletal disorders. Consensus was reached on the content of all risk of bias and evidence tables. All randomized controlled trials with high or acceptable quality found that SMT was not superior to sham interventions for the treatment of these non-musculoskeletal disorders. Six of 50 participants (12%) in the Global Summit did not approve the final report. CONCLUSION: Our systematic review included six randomized clinical trials (534 participants) of acceptable or high quality investigating the efficacy or effectiveness of SMT for the treatment of non-musculoskeletal disorders. We found no evidence of an effect of SMT for the management of non-musculoskeletal disorders including infantile colic, childhood asthma, hypertension, primary dysmenorrhea, and migraine. This finding challenges the validity of the theory that treating spinal dysfunctions with SMT has a physiological effect on organs and their function. Governments, payers, regulators, educators, and clinicians should consider this evidence when developing policies about the use and reimbursement of SMT for non-musculoskeletal disorders.

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.

Optimization of Spinal Manipulative Therapy Protocols: A Factorial Randomized Trial Within a Multiphase Optimization Framework.

Spinal manipulative therapy (SMT) is a common nonpharmacological treatment for low back pain (LBP). Although generally supported by systematic reviews and practice guidelines, clinical trials evaluating SMT have been characterized by small effect sizes. This study adopts a Multiphase Optimization Strategy framework to examine individual components of an SMT delivery protocol using a single-blind trial with the goal of identifying and optimizing a multicomponent SMT protocol. We enrolled 241 participants with LBP. All participants received 2 SMT treatment sessions in the first week then were randomly assigned additional treatment based on a fully factorial design. The 3 randomized treatment components provided in twice weekly sessions over 3 weeks were multifidus activating exercise, spinal mobilizing exercise, and additional SMT dose. Primary outcomes included clinical (Oswestry Disability Index, numeric pain intensity rating) and mechanistic (spinal stiffness, multifidus muscle activation) measures assessed at baseline, 1, 4, and 12 weeks. Significant differences were found for the Oswestry index after 12 weeks for participants receiving multifidus activating exercise (mean difference = -3.62, 97.5% CI: -6.89, -0.35; P= .01). There were no additional significant main or interaction effects for other treatment components or different outcome measures. The optimized SMT protocol identified in this study included SMT sessions followed by multifidus activating exercises. PERSPECTIVE: Optimizing the effects of nonpharmacological treatments such as SMT for LBP is challenging due to uncertainty regarding mechanisms and the complexity of multicomponent protocols. This factorial randomized trial examined SMT protocols provided with differing co-interventions with mechanistic and patient-centered outcomes. Patient-centered outcomes were optimized by inclusion of lumbar multifidus strengthening exercises.

Force Distribution Within Spinal Tissues During Posterior to Anterior Spinal Manipulative Therapy: A Secondary Analysis.

BACKGROUND: Previous studies observed that the intervertebral disc experiences the greatest forces during spinal manipulative therapy (SMT) and that the distribution of forces among spinal tissues changes as a function of the SMT parameters. However, contextualized SMT forces, relative to the ones applied to and experienced by the whole functional spinal unit, is needed to understand SMT's underlying mechanisms. AIM: To describe the percentage force distribution between spinal tissues relative to the applied SMT forces and total force experienced by the functional unit. METHODS: This secondary analysis combined data from 35 fresh porcine cadavers exposed to a simulated 300N SMT to the skin overlying the L3/L4 facet joint via servo-controlled linear motor actuator. Vertebral kinematics were tracked optically using indwelling bone pins. The functional spinal unit was then removed and mounted on a parallel robotic platform equipped with a 6-axis load cell. The kinematics of the spine during SMT were replayed by the robotic platform. By using serial dissection, peak and mean forces induced by the simulated SMT experienced by spinal structures in all three axes of motion were recorded. Forces experienced by spinal structures were analyzed descriptively and the resultant force magnitude was calculated. RESULTS: During SMT, the functional spinal unit experienced a median peak resultant force of 36.4N (IQR: 14.1N) and a mean resultant force of 25.4N (IQR: 11.9N). Peak resultant force experienced by the spinal segment corresponded to 12.1% of the total applied SMT force (300N). When the resultant force experienced by the functional spinal unit was considered to be 100%, the supra and interspinous ligaments experienced 0.3% of the peak forces and 0.5% of the mean forces. Facet joints and ligamentum flavum experienced 0.7% of the peak forces and 3% of the mean forces. Intervertebral disc and longitudinal ligaments experienced 99% of the peak and 96.5% of the mean forces. CONCLUSION: In this animal model, a small percentage of the forces applied during a posterior-to-anterior SMT reached spinal structures in the lumbar spine. Most SMT forces (over 96%) are experienced by the intervertebral disc. This study provides a novel perspective on SMT force distribution within spinal tissues.