Subgrouping Patients With Nonspecific Low Back Pain: Hope or Hype?

Machine Learning Models for Low Back Pain Detection and Factor Identification: Insights From a 6-Year Nationwide Survey

This study aimed to enhance performance, identify additional predictors, and improve the interpretability of biopsychosocial machine learning models for low back pain (LBP). Using survey data from a 6-year nationwide study involving 17,609 adults aged ≥50 years (Korea National Health and Nutrition Examination Survey), we explored 119 factors to detect LBP in individuals who reported experiencing LBP for at least 30 days within the previous 3 months. Our primary model, model 1, employed eXtreme Gradient Boosting (XGBoost) and selected primary factors (PFs) based on their feature importance scores. To extend this, we introduced additional factors, such as lumbar X-ray findings, physical activity, sitting time, and nutrient intake levels, which were available only during specific survey periods, into models 2 to 4. Model performance was evaluated using the area under the curve, with predicted probabilities explained by SHapley Additive exPlanations. Eleven PFs were identified, and model 1 exhibited an enhanced area under the curve .8 (.77-.84, 95% confidence interval). The factors had varying impacts across individuals, underscoring the need for personalized assessment. Hip and knee joint pain were the most significant PFs. High levels of physical activity were found to have a negative association with LBP, whereas a high intake of omega-6 was found to have a positive association. Notably, we identified factor clusters, including hip joint pain and female sex, potentially linked to osteoarthritis. In summary, this study successfully developed effective XGBoost models for LBP detection, thereby providing valuable insight into LBP-related factors. Comprehensive LBP management, particularly in women with osteoarthritis, is crucial given the presence of multiple factors. PERSPECTIVE: This article introduces XGBoost models designed to detect LBP and explores the multifactorial aspects of LBP through the application of SHapley Additive exPlanations and network analysis on the 4 developed models. The utilization of this analytical system has the potential to aid in devising personalized management strategies to address LBP.

A systematic review and meta analysis of measurement properties for the flexion relaxation ratio in people with and without non specific spine pain

This review sought to identify, critically appraise, compare, and summarize the literature on the reliability, discriminative validity and responsiveness of the flexion relaxation ratio (FRR) in adults (≥ 18 years old) with or without spine pain (any duration), in either a clinical or research context. The review protocol was registered on Open Science Framework ( https://doi.org/10.17605/OSF.IO/27EDF ) and follows COSMIN, PRISMA, and PRESS guidelines. Six databases were searched from inception to June 1, 2022. The search string was developed by content experts and a health services librarian. Two pairs of reviewers independently completed titles/abstracts and full text screening for inclusion, data extraction, and risk of bias assessment (COSMIN RoB Toolkit). At all stages, discrepancies were resolved through consensus meetings. Data were pooled where possible with a three-level random effects meta-analyses and a modified GRADE assessment was used for the summary of findings. Following duplicate removal, 728 titles/abstracts and 219 full texts were screened with 23 included in this review. We found, with moderate certainty of evidence, that the cervical FRR has high test-retest reliability and lumbar FRR has moderate to high test-retest reliability, and with high certainty of evidence that the cervical and lumbar FRR can discriminate between healthy and clinical groups (standardized mean difference - 1.16 [95% CI - 2.00, - 0.32] and - 1.21 [- 1.84, - 0.58] respectively). There was not enough evidence to summarize findings for thoracic FRR discriminative validity or the standard error of measurement for the FRR. Several studies used FRR assuming responsiveness, but no studies were designed in a way that could confirm responsiveness. The evidence supports adequate reliability of FRR for the cervical and lumbar spine, and discriminative validity for the cervical and lumbar spine only. Improvements in study design and reporting are needed to strengthen the evidence base to determine the remaining measurement properties of this outcome.

Temporal stability in the prevalence and pattern of co-occurring musculoskeletal pain among people with persistent low back pain: population-based data from the Norwegian HUNT Study, 1995 to 2019

ABSTRACT

People with persistent low back pain (LBP) often report co-occurring persistent musculoskeletal (MSK) pain in other body regions that may influence prognosis as well as treatment approaches and outcomes. This study describes the prevalence and patterns of co-occurring persistent MSK pain among people with persistent LBP based on consecutive cross-sectional studies over 3 decades in the population-based HUNT Study, Norway. The analyses comprised 15,375 participants in HUNT2 (1995-1997), 10,024 in HUNT3 (2006-2008), and 10,647 in HUNT4 (2017-2019) who reported persistent LBP. Overall, ∼90% of participants in each of the HUNT surveys with persistent LBP reported persistent co-occurring MSK pain in other body sites. The age-standardized prevalence of the most common co-occurring MSK pain sites was consistent across the 3 surveys: 64% to 65% report co-occurring neck pain, 62% to 67% report shoulder pain, and 53% to 57% report hip or thigh pain. Using latent class analysis (LCA), we identified 4 distinct patterns of persistent LBP phenotypes that were consistent across the 3 surveys: (1) "LBP only," (2) "LBP with neck or shoulder pain," (3) "LBP with lower extremity or wrist or hand pain," and (4) "LBP with multisite pain," with conditional item response probabilities of 34% to 36%, 30% to 34%, 13% to 17%, and 16% to 20%, respectively. In conclusion, 9 of 10 adults in this Norwegian population with persistent LBP report co-occurring persistent MSK pain, most commonly in the neck, shoulders, and hips or thighs. We identified 4 LCA-derived LBP phenotypes of distinct MSK pain site patterns. In the population, both the prevalence and pattern of co-occurring MSK pain and the distinct phenotypic MSK pain patterns seem stable over decades.

Diagnostic clinical prediction rules for categorising low back pain: A systematic review

BACKGROUND

Low back pain (LBP) is a common complex condition, where specific diagnoses are hard to identify. Diagnostic clinical prediction rules (CPRs) are known to improve clinical decision-making. A review of LBP diagnostic-CPRs by Haskins et al. (2015) identified six diagnostic-CPRs in derivation phases of development, with one tool ready for implementation. Recent progress on these tools is unknown. Therefore, this review aimed to investigate developments in LBP diagnostic-CPRs and evaluate their readiness for implementation.

METHODS

A systematic review was performed on five databases (Medline, Amed, Cochrane Library, PsycInfo, and CINAHL) combined with hand-searching and citation-tracking to identify eligible studies. Study and tool quality were appraised for risk of bias (Quality Assessment of Diagnostic Accuracy Studies-2), methodological quality (checklist using accepted CPR methodological standards), and CPR tool appraisal (GRade and ASsess Predictive).

RESULTS

Of 5021 studies screened, 11 diagnostic-CPRs were identified. Of the six previously known, three have been externally validated but not yet undergone impact analysis. Five new tools have been identified since Haskin et al. (2015); all are still in derivation stages. The most validated diagnostic-CPRs include the Lumbar-Spinal-Stenosis-Self-Administered-Self-Reported-History-Questionnaire and Diagnosis-Support-Tool-to-Identify-Lumbar-Spinal-Stenosis, and the StEP-tool which differentiates radicular from axial-LBP.

CONCLUSIONS

This updated review of LBP diagnostic CPRs found five new tools, all in the early stages of development. Three previously known tools have now been externally validated but should be used with caution until impact evaluation studies are undertaken. Future funding should focus on externally validating and assessing the impact of existing CPRs on clinical decision-making.

Identifying chronic low back pain phenotypic domains and characteristics accounting for individual variation: a systematic review

ABSTRACT

Interpatient variability is frequently observed among individuals with chronic low back pain (cLBP). This review aimed at identifying phenotypic domains and characteristics that account for interpatient variability in cLBP. We searched MEDLINE ALL (through Ovid), Embase Classic and EMBASE (through Ovid), Scopus, and CINAHL Complete (through EBSCOhost) databases. Studies that aimed to identify or predict cLBP different phenotypes were included. We excluded studies that focused on specific treatments. The methodological quality was assessed using an adaptation of the Downs and Black tool. Forty-three studies were included. Although the patient and pain-related characteristics used to identify phenotypes varied considerably across studies, the following were among the most identified phenotypic domains and characteristics that account for interpatient variability in cLBP: pain-related characteristics (including location, severity, qualities, and duration) and pain impact (including disability, sleep, and fatigue), psychological domains (including anxiety and depression), behavioral domains (including coping, somatization, fear avoidance, and catastrophizing), social domains (including employment and social support), and sensory profiling (including pain sensitivity and sensitization). Despite these findings, our review showed that the evidence on pain phenotyping still requires further investigation. The assessment of the methodological quality revealed several limitations. We recommend adopting a standard methodology to enhance the generalizability of the results and the implementation of a comprehensive and feasible assessment framework to facilitate personalized treatments in clinical settings.

Not all movements are equal: Differences in the variability of trunk motor behavior between people with and without low back pain-A systematic review with descriptive synthesis

BACKGROUND

Differences in variability of trunk motor behavior between people with and without low back pain (LBP) have been reported in the literature. However, the direction and consistency of these differences remain unclear. Understanding variability of trunk motor behavior between individuals with LBP and those without is crucial to better understand the impact of LBP and potentially optimize treatment outcomes. Identifying such differences may help tailor therapeutic interventions.

OBJECTIVE

This systematic review aims to answer the question: Is variability of trunk motor behavior different between people with and without LBP and if so, do people with LBP show more or less variability? Furthermore, we addressed the question whether the results are dependent on characteristics of the patient group, the task performed and the type of variability measure.

METHODS

This study was registered in PROSPERO (CRD42020180003). A comprehensive systematic literature search was performed by searching PubMed, Embase, Cinahl, Cochrane Central Register of Controlled Trials, Web of Science and Sport Discus. Studies were eligible if they (1) included a LBP group and a control group, (2) included adults with non-specific low back pain of any duration and (3) measured kinematic variability, EMG variability and/or kinetic variability. Risk of Bias was evaluated and a descriptive synthesis was performed.

RESULTS

Thirty-nine studies were included, thirty-one of which were included in the descriptive synthesis. In most studies and experimental conditions, variability did not significantly differ between groups. When significant differences were found, less variability in patients with LBP was more frequently reported than more variability, especially in gait-related tasks.

CONCLUSIONS

Given the considerable risk of bias of the included studies and the clinical characteristics of the participants with low severity scores for pain, disability and psychological measures, there is insufficient evidence to draw firm conclusions.

Public and patient perceptions of diagnostic labels for non-specific low back pain: a content analysis

PURPOSE

An online randomised experiment found that the labels lumbar sprain, non-specific low back pain (LBP), and episode of back pain reduced perceived need for imaging, surgery and second opinions compared to disc bulge, degeneration, and arthritis among 1447 participants with and without LBP. They also reduced perceived seriousness of LBP and increased recovery expectations.

METHODS

In this study we report the results of a content analysis of free-text data collected in our experiment. We used two questions: 1. When you hear the term [one of the six labels], what words or feelings does this make you think of? and 2. What treatment (s) (if any) do you think a person with [one of the six labels] needs? Two independent reviewers analysed 2546 responses.

RESULTS

Ten themes emerged for Question1. Poor prognosis emerged for disc bulge, degeneration, and arthritis, while good prognosis emerged for lumbar sprain, non-specific LBP, and episode of back pain. Thoughts of tissue damage were less common for non-specific LBP and episode of back pain. Feelings of uncertainty frequently emerged for non-specific LBP. Twenty-eight treatments emerged for Question2. Surgery emerged for disc bulge, degeneration, and arthritis compared to lumbar sprain, non-specific LBP, and episode of back pain. Surgery did not emerge for non-specific LBP and episode of back pain.

CONCLUSION

Our results suggest that clinicians should consider avoiding the labels disc bulge, degeneration and arthritis and opt for labels that are associated with positive beliefs and less preference for surgery, when communicating with patients with LBP.

Treatment-based classification for low back pain: systematic review with meta-analysis

OBJECTIVE

To systematically review the effects of treatment-based classification (TBC) in patients with specific and nonspecific acute, subacute and chronic low back pain.

METHODS

The following databases were searched: MEDLINE, EMBASE, PsycINFO, Global Health, CENTRAL, Web of Science, CINAHL, SPORTDiscus, PEDro and WHO from inception up to December 2021. We used the PEDro scale, the TIDieR checklist and the GRADE approach to evaluate the risk of bias, quality on reporting and the certainty of the evidence, respectively.

RESULTS

Twenty-three trials (pooled n = 2,649) met the inclusion criteria. We have identified a total of 22 comparisons and 134 estimates of treatment effects. There was a very large heterogeneity with regards to the comparison groups. Most of individual trials had low risk of bias with a mean score of 6.8 (SD = 1.3) on a 0-10 scale. The certainty of evidence for most comparisons was low, which indicates that more high quality and robust trials are needed. We were able to pool the data using a meta-analysis approach for only two comparisons (TBC versus mobility exercises in patients with acute low back pain and traction for patients with sciatica). In general, the TBC approach seems to be useful for patients with acute low back pain, sciatica and with spinal stenosis. We strongly suggest readers to carefully read our summary of findings table for further details on each comparison.

CONCLUSION

The TBC approach seems to be useful for patients with acute low back pain, sciatica and with spinal stenosis.

Relative contributions of the nervous system, spinal tissue and psychosocial health to non-specific low back pain: Multivariate meta-analysis

BACKGROUND AND OBJECTIVES

Nervous system, psychosocial and spinal tissue biomarkers are associated with non-specific low back pain (nsLBP), though relative contributions are unclear.

DATABASES AND DATA TREATMENT

MEDLINE, EMBASE, CINAHL, PsycINFO and SPORTDiscus were searched up to 25 March 2020. Related reviews and reference lists were also screened. Observational studies examining structural and functional nervous system biomarkers (e.g. quantitative sensory tests, structural and functional brain measures), psychosocial factors (e.g. mental health, catastrophizing) and structural spinal imaging biomarkers (e.g. intervertebral disc degeneration, paraspinal muscle size) between nsLBP and pain-free controls were included. For multivariate meta-analysis, two of three domains were required in each study. Random-effects pairwise and multivariate meta-analyses were performed. GRADE approach assessed evidence certainty. Newcastle-Ottawa scale assessed risk of bias. Main outcomes were the effect size difference of domains between nsLBP and pain-free controls.

RESULTS

Of 4519 unique records identified, 33 studies (LBP = 1552, referents = 1322) were meta-analysed. Psychosocial state (Hedges' g [95%CI]: 0.90 [0.69-1.10], p < 0.001) in nsLBP showed larger effect sizes than nervous system (0.31 [0.13-0.49], p < 0.001; difference: 0.61 [0.36-0.86], p < 0.001) and spine imaging biomarkers (0.55 [0.37-0.73], p < 0.001; difference: 0.36 [0.04-0.67], p = 0.027). The relationship between domains changes depending on if pain duration is acute or chronic.

CONCLUSIONS

Psychosocial effect sizes in nsLBP are greater than that for spinal imaging and nervous system biomarkers. Limitations include cross-sectional design of studies included and inference of causality. Future research should investigate the clinical relevance of these effect size differences in relation to pain intensity and disability.

STUDY REGISTRATION

PROSPERO-CRD42020159188.

SIGNIFICANCE

Spinal imaging (e.g. intervertebral disc degeneration), psychosocial (e.g. depression) and nervous system (e.g. quantitative sensory tests, structural and functional brain measures) biomarkers contribute to non-specific low back pain. However, psychosocial factors may be more compromised than nervous system and spinal imaging biomarkers. This relationship depends on if the pain is acute or chronic. These findings underscore that the 'non-specific' label in back pain should be reconsidered, and more specific multidimensional categories evaluated to guide patient management.

The Changes of Motor Control Strategies in Non-specific Chronic Low Back Pain During Spinal Manipulation and Muscle Energy Techniques: A Beta-band Intermuscular Pair-Wise Coherence Analysis

Background: Until now, a variety of techniques have been introduced to address the adverse effects of NS-CLBP, including spinal manipulation technique (SMT) and muscle energy technique (MET). However, most of these techniques have focused on pain assessment and disability. In other words, the intermuscular synchronization between the co-contracting muscles was not considered, and hence, the effectiveness of these techniques on the corticospinal tract function was not studied. Objectives: This study aimed to compare the effects of SMT and MET on corticospinal tract function during four phases of standing, flexion, relaxation, and extension in flexion-extension task (F-ET) in NS-CLBP using pair-wise coherence of Beta-band intermuscular coherence (Bb-IMC). Methods: Twenty volunteer healthy male subjects and twenty-four male subjects with NS-CLBP (20 - 45 years of age) participated in this work. The patients had continuous or recurrent symptoms for three months or more without any referral pain to the lower extremities. The patients were randomly assigned to two equal intervention groups (SMT and MET), and the techniques were applied as described by Greenman. Surface electromyography (sEMGs) from lumbopelvic muscles was recorded for all participants (i.e., healthy group and the patient groups), while they performed three trials of F-ET, and the pair-wise coherence for all muscles was calculated using Bb-IMC analysis. Besides, in the patient's groups, sEMGs from the muscles were recorded before and after the interventional techniques (i.e., SMT and MET), while they performed three trials of F-ET, and the pair-wise coherence was calculated. Multivariate analysis of variance test was used to compare the healthy subjects and patient groups before the interventions in A and B muscle cross at different phases of F-ET task. Furthermore, in the NS-CLBP patients, comparisons were made before and after the interventions in each group (i.e., SMT and MET groups) as well as between the two groups in A and B muscle cross at different phases of the F-ET task. Results: In the standing phase of F-ET, there were no significant differences in the SMT and MET group before and after the intervention in PWC of A muscle cross and B muscle cross (P < 0.05). Considering the flexion phase, there were significant differences in the SMT group in all pair muscles as PWC (M1-M4), PWE (M1-M6), PWC (M4-M6) (P < 0.05), whereas there was one significantly in PWC (M4-M6) in the MET group (P < 0.05). In the relaxation phase, the SMT had significantly in PWC (M2-M5), whereas there was one significantly in PWC (M4-M6) in MET group (P < 0.05). In the extension phase, although the SMT was not significant (P < 0.05) in the MET intervention group, there were significant differences in the PWC (M2-M3) and PWC muscles (M2-M5). Conclusions: This study provided some pieces of evidence about the effects of one of the common manual therapy techniques on the primary motor cortex and corticospinal drive in the NS-CLBP patients. The results showed that, by increasing the pair-wise coherence in all phases of FE-T, SMT intervention was more effective than MET intervention. Therefore, the pair-wise coherence of Bb-IMC can be considered an approach for clinicians when designing the rehabilitation protocol to ensure optimal treatment.

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.

[Results of Rehabilitation in Chronic Non-Specific Back Pain in Germany - Meta-Analyses of Change Scores of Pain Intensity and Functional Capacity]

OBJECTIVE

How do pain intensity and functional capacity improve after rehabilitating chronic non-specific back pain? Are the changes of practical relevance for quality of life and social participation? Are they stronger than placebo effects?

METHODS

Meta-analyses of short-, medium- and long-term outcomes from rehabilitation studies with standardized mean differences and MID-units were performed, as well as meta-analyses of outcomes of sham therapies. In addition, non-standardized effect measures and the amount of reliable change were determined.

RESULTS

for pain intensity short-term effects were moderate, long-term effects were small, for functional capacity short-term effects were small, and no effects occurred in the long term. The effects were at no time of practical relevance. Similar results could be achieved with sham treatments.

CONCLUSION

As far as pain intensity and functional capacity are concerned, the typical rehabilitee does not experience any significant improvements; a smaller proportion achieve results in the range of placebo effects.

Clinical utility of a cluster of tests as a diagnostic support tool for clinical lumbar instability

BACKGROUND

Numerous clinical tests have been proposed for the diagnosis of clinical lumbar instability (CLI), but a cluster of clinical tests is still needed to increase the accuracy of CLI diagnosis.

OBJECTIVE

To evaluate a diagnostic support tool intended to identify the presence of CLI using a cluster of clinical tests.

DESIGN

Analytical cross-sectional study.

METHODS

Two hundred participants with chronic low back pain (LBP) were diagnosed with or without CLI by an orthopedic surgeon. The orthopedic surgeon made the diagnosis from classic clinical symptoms and signs. The diagnosis was used as the reference standard. An orthopedic physical therapist used four clinical tests to identify CLI in each participant, including the apprehension sign, the instability catch sign with/without the abdominal drawing-in maneuver (ADIM), the painful catch sign with/without the ADIM, and the prone instability test.

RESULTS

For an individual test, the apprehension sign showed a high specificity (92.6%) and a positive likelihood ratio (LR+; 2.4) but a very low sensitivity of 17.4%. A cluster of three of the four examined tests provided the most diagnostic accuracy for CLI, with a high LR+ (5.8) and a high specificity (91.7%) but low sensitivity (47.8%) and a negative likelihood ratio (LR-; 0.6).

CONCLUSIONS

A cluster of three of the four examined tests was determined to comprise a powerful clinical support tool for the identification of CLI patients as tested against a reference standard diagnosis.

CLINICAL TRIAL REGISTRATION

Name of the registry: Thai Clinical Trials Registry. Registration number: TCTR20190426002.

Effectiveness of mechanical diagnosis and therapy in patients with non-specific chronic low back pain: a literature review with meta-analysis

OBJECTIVE

To determine the effectiveness of mechanical diagnosis and therapy (MDT) in patients with chronic low back pain (CLBP) compared to other traditional physical therapy interventions.

METHODS

Randomized controlled trials investigating the effect of MDT compared to other traditional physical therapy interventions in individuals with CLBP were considered eligible. For the purpose of this review, MDT was compared to active and passive physical therapy interventions. Independent reviewers assessed the eligibility of studies, extracted data, and assessed the risk of bias. The primary outcomes investigated were pain and disability.

RESULTS

Fourteen studies were included in the review. Of these, 11 provided data to be included in the meta-analyses. Our findings showed that MDT was no more effective in decreasing pain (standardized mean difference [SMD]=0.01, 95% confidence interval [CI]: -0.44, 0.46) and disability (SMD=0.08, 95% CI: -0.53, 0.68) than other active treatments. Similar results were found when comparing MDT to other passive treatments for pain (SMD=-0.39, 95% CI: -0.90, 0.11) and disability (SMD=-0.13, 95% CI: -0.29, 0.03).

CONCLUSION

There is low to moderate quality evidence that MDT is not superior than other traditional physical therapy interventions in improving pain and disability in people with CLBP.

The pelvic girdle pain deadlock: 1. Would 'deconstruction' help?

INTRODUCTION

Pelvic Girdle Pain (PGP) is an important clinical problem that deserves more attention. Several treatment regimens have been presented that appear to be somewhat promising, but it was reported that about 10% of patients still suffer from the problems 11 years after their inception. This situation should be improved.

PURPOSE

We present a personalized history, with first the acceptance of the concept of 'PGP', around 2005, and then continued problems in really understanding PGP's nature and causes. We propose to engage in 'deconstruction' of PGP, that is, disentangling the large variety of processes involved.

IMPLICATIONS

Deconstructing PGP is a venture into the unknown. Still, science should proceed on the basis of what we know already. To understand PGP, experts emphasize the importance of biomechanics or of psychology, and we propose to insert 'inflammation' between these two levels of understanding, that is to say, the full development from low grade local inflammation to systemic inflammation and neuroinflammation. Inflammation is bidirectionally related to biomechanical as well as psychological processes. For clinicians, challenging our "beliefs and understanding of PGP, rather than being 'stuck' with a preferred modus operandi" has major practical implications. It requires continuous monitoring of the patient, and a willingness to change direction. More scientific disciplines are relevant to understanding, and treating, PGP than a single human being can master. Creative flexibility of clinicians would be a promising starting point to improve overall treatment effects in PGP.

Predictors of instanteous relief from spinal manipulation for non-specific low back pain: a delphi study

Background

There is some evidence and anecdotal reports that high-velocity low-amplitude (HVLA) spinal manipulation therapy (SMT) for non-specific low back pain (NSLBP) may immediately reduce pain in some patients. The mechanism for such a change remains unclear and the evidence is conflicting. The aim of this study was to seek consensus among a sample of expert manual therapists as to the possible clinical predictors that could help identify patients who are most likely to receive instant relief from NSLBP with SMT intervention.

Methods

Thirty-seven expert chiropractors and manipulative physiotherapists from around the world were invited to participate in a three round online Delphi questionnaire during the second half of 2018. Participants were provided with a list of 55 potential signs and symptoms as well as offering them the option of suggesting other factors in the first round. The variables were rated using a 4-point Likert likelihood scale and a threshold of 75% agreement was required for any item to progress to the next round.

Results

Of these 37 experts, 19 agreed to participate. Agreement as to the proportion of patients who receive instantaneous relief was minimal (range 10–80%). A total of 62 items were ranked over the 3 rounds, with 18 of these retained following the third round. The highest rated of the 18 was ‘A history including a good response to previous spinal manipulation’.

Discussion/conclusion

Five categories; patient factors, practitioner factors, signs and symptoms of NSLBP presentation, an instrument of measurement (FABQ), and the presence of cavitation following SMT best describe the overall characteristics of the factors. The 18 factors identified in this study can potentially be used to create an instrument of measurement for further study to predict those patients with NSLBP who will receive instantaneous relief post-SMT.

Comorbidity Subgroups Among Medicare Beneficiaries Seeking Health Care for Musculoskeletal Pain

BACKGROUND

Treatment of musculoskeletal pain in older adults may be more effective if it incorporates integrated management of comorbid health conditions. The purpose of this study was to define empirically derived comorbidity subgroups among Medicare beneficiaries with an index condition of osteoarthritis (OA) or low back pain (LBP) as a precursor to the development of comorbidity-specific pain treatment pathways.

METHODS

This study included Medicare beneficiaries participating in the Medicare Current Beneficiary Survey (MCBS) and seeking care for OA (n = 723) or LBP (n = 617) with data available for 3 years after entry into the survey. We identified 30 comorbidity diagnoses using International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) diagnostic codes in claims data during beneficiaries' first year in the survey. Latent class analysis defined comorbidity subgroups, and posterior probabilities were used to assign subgroup classification. Self-reported disability was compared over three consecutive years for each subgroup.

RESULTS

We identified similar comorbidity subgroups for OA and LBP. The subgroups included (range of percent prevalence) low comorbidity (47.6%-54.4%), nonvascular (21.8%-28.6%), diabetes (12.2%-15.0%), renal disease with complicated hypertension (5.5%-5.8%), and complex cardiac disease/high comorbidity (3.3%-5.8%). OA and LBP subgroups with more complex comorbidity burden generally demonstrated higher disability over 3 years.

CONCLUSIONS

Five comorbidity subgroups were identified, with a large proportion of older adults classified into the subgroup defined by a low probability of most comorbidities. These findings provide direction for the development of pain treatment pathways that are tailored to address common comorbidity profiles among older adults.

Randomized Trial of General Strength and Conditioning Versus Motor Control and Manual Therapy for Chronic Low Back Pain on Physical and Self-Report Outcomes

Exercise and spinal manipulative therapy are commonly used for the treatment of chronic low back pain (CLBP) in Australia. Reduction in pain intensity is a common outcome; however, it is only one measure of intervention efficacy in clinical practice. Therefore, we evaluated the effectiveness of two common clinical interventions on physical and self-report measures in CLBP. Participants were randomized to a 6-month intervention of general strength and conditioning (GSC; n = 20; up to 52 sessions) or motor control exercise plus manual therapy (MCMT; n = 20; up to 12 sessions). Pain intensity was measured at baseline and fortnightly throughout the intervention. Trunk extension and flexion endurance, leg muscle strength and endurance, paraspinal muscle volume, cardio-respiratory fitness and self-report measures of kinesiophobia, disability and quality of life were assessed at baseline and 3- and 6-month follow-up. Pain intensity differed favoring MCMT between-groups at week 14 and 16 of treatment (both, p = 0.003), but not at 6-month follow-up. Both GSC (mean change (95%CI): −10.7 (−18.7, −2.8) mm; p = 0.008) and MCMT (−19.2 (−28.1, −10.3) mm; p < 0.001) had within-group reductions in pain intensity at six months, but did not achieve clinically meaningful thresholds (20mm) within- or between-group. At 6-month follow-up, GSC increased trunk extension (mean difference (95% CI): 81.8 (34.8, 128.8) s; p = 0.004) and flexion endurance (51.5 (20.5, 82.6) s; p = 0.004), as well as leg muscle strength (24.7 (3.4, 46.0) kg; p = 0.001) and endurance (9.1 (1.7, 16.4) reps; p = 0.015) compared to MCMT. GSC reduced disability (−5.7 (−11.2, −0.2) pts; p = 0.041) and kinesiophobia (−6.6 (−9.9, −3.2) pts; p < 0.001) compared to MCMT at 6-month follow-up. Multifidus volume increased within-group for GSC (p = 0.003), but not MCMT or between-groups. No other between-group changes were observed at six months. Overall, GSC improved trunk endurance, leg muscle strength and endurance, self-report disability and kinesiophobia compared to MCMT at six months. These results show that GSC may provide a more diverse range of treatment effects compared to MCMT.

Potential treatment effect modifiers for manipulative therapy for children complaining of spinal pain.Secondary analyses of a randomised controlled trial

Background

In children, spinal pain is transitory for most, but up to 20% experience recurrent and bothersome complaints. It is generally acknowledged that interventions may be more effective for subgroups of those affected with low back pain. In this secondary analysis of data from a randomized clinical trial, we tested whether five indicators of a potential increased need for treatment might act as effect modifiers for manipulative therapy in the treatment of spinal pain in children. We hypothesized that the most severely affected children would benefit more from manipulative therapy.

Method

This study was a secondary analysis of data from a randomised controlled trial comparing advice, exercises and soft tissue treatment with and without the addition of manipulative therapy in 238 Danish school children aged 9-15 years complaining of spinal pain. A text message system (SMS) and clinical examinations were used for data collection (February 2012 to April 2014).Five pre-specified potential effect modifiers were explored: Number of weeks with spinal pain 6 months prior to inclusion, number of weeks with co-occurring musculoskeletal pain 6 months prior to inclusion, expectations of the clinical course, pain intensity, and quality of life.Outcomes were number of recurrences of spinal pain, number of weeks with pain, length of episodes, global perceived effect, and change in pain intensity. To explore potential effect modification, various types of regression models were used depending on the type of outcome, including interaction tests.

Results

We found that children with long duration of spinal pain or co-occurring musculoskeletal pain prior to inclusion as well as low quality of life at baseline tended to benefit from manipulative therapy over non-manipulative therapy, whereas the opposite was seen for children reporting high intensity of pain. However, most results were statistically insignificant.

Conclusions

This secondary analysis indicates that children more effected by certain baseline characteristics, but not pain intensity, have a greater chance to benefit from treatment that include manipulative therapy. However, these analyses were both secondary and underpowered, and therefore merely exploratory. The results underline the need for a careful choice of inclusion criteria in future investigations of manipulative therapy in children.

Trial registration

NCT01504698; results.

Chronic low back pain is highly individualised: patterns of classification across three unidimensional subgrouping analyses

BACKGROUND AND AIMS

Chronic low back pain (CLBP) is a complex disorder where central and peripheral nociceptive processes are influenced by factors from multiple dimensions associated with CLBP (e.g. movement, pain sensitivity, psychological). To date, outcomes for treatments matched to unidimensional subgroups (e.g. psychologically-based) have been poor. Therefore, unidimensional subgrouping may not reflect the complexity of CLBP presentations at an individual level. The aim of this study was therefore to explore patterns of classification at an individual level across the three previously-published, data-driven, within-dimension subgrouping studies.

METHODS

Cross-sectional, multidimensional data was collected in 294 people with CLBP. Statistical derivation of subgroups within each of three clinically-important dimensions (pain sensitivity, psychological profile, pain responses following repeated spinal bending) was briefly reviewed. Patterns of classification membership were subsequently tabulated across the three dimensions.

RESULTS

Of 27 possible patterns across these dimensions, 26 were represented across the cohort.

CONCLUSIONS

This result highlights that while unidimensional subgrouping has been thought useful to guide treatment, it is unlikely to capture the full complexity of CLBP. The amount of complexity important for best patient outcomes is currently untested.

IMPLICATIONS

For clinicians this study highlights the high variability of presentations of people with CLBP at the level of the individual. For example, clinician's should not assume that those with high levels of pain sensitivity will also have high psychological distress and have pain summation following repeated spinal bending. A more flexible, multidimensional, clinically-reasoned approach to profile patient complexity may be required to inform individualised, patient-centred care. Such individualised care might improve treatment efficacy. This study also has implications for researchers; highlighting the inadequacy of unidimensional subgrouping processes and methodological difficulties in deriving subgroups across multidimensional data.

Can Biomechanics Research Lead to More Effective Treatment of Low Back Pain? A Point-Counterpoint Debate

SYNOPSIS

Although biomechanics plays a role in the development and perhaps the persistent or recurrent nature of low back pain (LBP), whether biomechanics alone can provide the basis for intervention is debated. Biomechanics, which refers to the mechanics of the body, including its neuromuscular control, has been studied extensively in LBP. But, can gains be made in understanding LBP by research focused on this component of biology in the multifactorial biopsychosocial problem of LBP? This commentary considers whether biomechanics research has the potential to advance treatment of LBP, and how likely it is that this research will lead to better treatment strategies. A point-counterpoint format is taken to present both sides of the argument. First, the challenges faced by an approach that considers biomechanics in isolation are presented. Next, we describe 3 models that place substantial emphasis on biomechanical factors. Finally, reactions to each point are presented as a foundation for further research and clinical practice to progress understanding of the place for biomechanics in guiding treatment of LBP. J Orthop Sports Phys Ther 2019;49(6):425-436. Epub 15 May 2019. doi:10.2519/jospt.2019.8825.

Neuroplasticity of Sensorimotor Control in Low Back Pain

Low back pain (LBP) is an important medical and socioeconomic problem. Impaired sensorimotor control has been suggested to be a likely mechanism underlying development and/or maintenance of pain. Although early work focused on the structural and functional abnormalities within the musculoskeletal system, in the past 20 years there has been an increasing realization that patients with LBP might also have extensive neuroplastic changes within the central nervous system. These include changes related to both the structure (eg, gray matter changes) and function (eg, organization of the sensory and motor cortices) of the nervous system as related to processing of pain and nociception and to motor and somatosensory systems. Moreover, clinical interventions increasingly aim to drive neuroplasticity with treatments to improve pain and sensorimotor function. This commentary provides a contemporary overview of neuroplasticity of the pain/nociceptive and sensorimotor systems in LBP. This paper addresses (1) defining neuroplasticity in relation to control of the spine and LBP, (2) structural and functional nervous system changes as they relate to nonspecific LBP and sensorimotor function, and (3) related clinical implications. Individuals with recurrent and persistent LBP differ from those without LBP in several markers of the nervous system's function and structure. Neuroplastic changes may be addressed by top-down cognitive-based interventions and bottom-up physical interventions. An integrated clinical approach that combines contemporary pain neuroscience education, cognition-targeted sensorimotor control, and physical or function-based treatments may lead to better outcomes in patients with recurrent and persistent LBP. This approach will need to consider variation among individuals, as no single finding/mechanism is present in all individuals, and no single treatment that targets neuroplastic changes in the sensorimotor system is likely to be effective for all patients with LBP. J Orthop Sports Phys Ther 2019;49(6):402-414. doi:10.2519/jospt.2019.8489.

Association Between Clinical Tests Related to Motor Control Dysfunction and Changes in Pain and Disability After Lumbar Stabilization Exercises in Individuals With Chronic Low Back Pain

OBJECTIVE

To investigate whether clinical tests used to detect motor control dysfunction can predict improvements in pain and disability in patients with chronic nonspecific low back pain (LBP) who have undergone an 8-week lumbar stabilization exercise program.

STUDY DESIGN

A prospective cohort study.

SETTING

Outpatient physical therapy university clinic.

PARTICIPANTS

Seventy people with chronic nonspecific LBP were recruited, and 64 completed the exercise program (N=64).

INTERVENTIONS

The lumbar stabilization program was provided twice a week for 8 weeks.

MAIN OUTCOME MEASURES

Pain intensity (11-point numerical rating scale) and disability (Roland Morris Disability Questionnaire) and clinical tests, such as the Deep Muscle Contraction (DMC) scale, Clinical Test of Thoracolumbar Dissociation (CTTD), and Passive Lumbar Extension (PLE) test. Univariate and multivariate linear regression models were used in the prediction analysis.

RESULTS

Mean changes in pain intensity and disability following the 8-week stabilization program were -3.8 (95% confidence interval [CI], -3.2 to -4.4) and -7.4 (95% CI, -6.3 to -8.5), respectively. Clinical test scores taken at baseline did not predict changes in pain and disability at 8-week follow-up.

CONCLUSION

Our findings revealed that the DMC scale, CTTD, PLE test, clinical tests used to assess motor control dysfunction, do not predict improvements in pain and disability in patients with chronic nonspecific LBP following an 8-week lumbar stabilization exercise program.

The influence of musculoskeletal pain disorders on muscle synergies-A systematic review

Background

Musculoskeletal (MSK) pain disorders represent a group of highly prevalent and often disabling conditions. Investigating the structure of motor variability in response to pain may reveal novel motor impairment mechanisms that may lead to enhanced management of motor dysfunction associated with MSK pain disorders. This review aims to systematically synthesize the evidence on the influence of MSK pain disorders on muscle synergies.

Methods

Nine electronic databases were searched using Medical Subject Headings and keywords describing pain, electromyography and synergies. Relevant characteristics of included studies were extracted and assessed for generalizability and risk of bias. Due to the significant heterogeneity, a qualitative synthesis of the results was performed.

Results

The search resulted in a total of 1312 hits, of which seven articles were deemed eligible. There was unclear consistency that pain reduced the number of muscle synergies. There were low consistencies of evidence that the synergy vector (W weights) and activation coefficient (C weights) differed in painful compared to asymptomatic conditions. There was a high consistency that muscle synergies were dissimilar between painful and asymptomatic conditions.

Conclusions

MSK pain alters the structure of variability in muscle control, although its specific nature remains unclear. Greater consistency in muscle synergy analysis may be achieved with appropriate selection of muscles assessed and ensuring consistent achievement of motor task outcomes. Synergy analysis is a promising method to reveal novel understandings of altered motor control, which may facilitate the assessment and treatment of MSK pain disorders.

Aberrant intervertebral motion in patients with treatment-resistant nonspecific low back pain: a retrospective cohort study and control comparison

PURPOSE

Intervertebral kinematic assessments have been used to investigate mechanical causes when back pain is resistant to treatment, and recent studies have identified intervertebral motion markers that discriminate patients from controls. However, such patients are a heterogeneous group, some of whom have structural disruption, but the effects of this on intervertebral kinematics are unknown.

METHODS

Thirty-seven patients with treatment-resistant back pain referred for quantitative fluoroscopy were matched to an equal number of pain-free controls for age and sex. All received passive recumbent flexion assessments for intervertebral motion sharing inequality (MSI), variability (MSV), laxity and translation. Comparisons were made between patient subgroups, between patients and controls and against normative levels from a separate group of controls.

RESULTS

Eleven patients had had surgical or interventional procedures, and ten had spondylolisthesis or pars defects. Sixteen had no disruption. Patients had significantly higher median MSI values (0.30) than controls (0.27, p = 0.010), but not MSV (patients 0.08 vs controls 0.08, p = 0.791). Patients who received invasive procedures had higher median MSI values (0.37) than those with bony defects (0.30, p = 0.018) or no disruption (0.28, p = 0.0007). Laxity and translation above reference limits were not more prevalent in patients.

CONCLUSION

Patients with treatment-resistant nonspecific back pain have greater MSI values than controls, especially if the former have received spinal surgery. However, excessive laxity, translation and MSV are not more prevalent in these patients. Thus, MSI should be investigated as a pain mechanism and for its possible value as a prognostic factor and/or target for treatment in larger patient populations. These slides can be retrieved under Electronic Supplementary Material.

Clinical classification criteria for nonspecific low back pain: A Delphi-survey of clinical experts

BACKGROUND

Nonspecific low back pain (NSLBP) is a common problem. Attempts have been made to classify NSLBP patients into homogenous subgroups. Classification systems based on identifying the underlying mechanism(s) driving the disorder are clinically useful to guide specific interventions.

OBJECTIVE

To establish consensus among experts regarding clinical criteria suggestive of a dominance of 'articular', 'myofascial', 'neural', 'central', and 'sensorimotor control' dysfunction patterns (DPs) in NSLBP patients.

STUDY DESIGN

A 2-phase sequential design of a focus group and Delphi-study.

METHODS

A focus group with 10 academic experts was organized to elaborate on the different DPs discernible in LBP patients. Consecutively, a 3-round online Delphi-survey was designed to obtain consensual symptoms and physical examination findings for the 5 DPs resulting from the focus group.

RESULTS

Fifteen musculoskeletal physical therapists from Belgium and the Netherlands experienced in assessing and treating LBP patients completed the Delphi-survey. Respectively, 34 (response rate, 100.0%), 20 (58.8%) and 15 (44.12%) respondents replied to rounds 1, 2 and 3. Twenty-two 'articular', 20 'myofascial', 21 'neural', 18 'central' and 11 'sensorimotor control' criteria reached a predefined ≥80% consensus level. For example, after round 2, 85.0% of the Delphi-experts agreed to identify 'referred pain below the knee' as a subjective examination criterion suggestive for a predominant 'neural DP'.

CONCLUSION

These indicators suggestive of a clinical dominance of the proposed DPs could help clinicians to assess and diagnose NSLBP patients. Future reliability and validity testing is needed to determine how these criteria may help to improve physical therapy outcome for NSLBP patients.

Pharmacotherapy for chronic non-specific low back pain: current and future options

INTRODUCTION

Low back pain is associated with a large burden-of-illness. It is responsible for the most years lived with disability as compared with any other medical condition. A comprehensive overview of the evidence on pharmacological treatment options for chronic low back pain is lacking. This review evaluates the evidence for the benefits and risks of currently available pharmacological treatments for chronic low back pain.

AREAS COVERED

The authors focus on the recent (Cochrane) systematic reviews and meta-analyses of randomized clinical trials covering paracetamol (acetaminophen), NSAIDs, muscle relaxants, antidepressants, anticonvulsants, opioids, and other (new) drugs.

EXPERT OPINION

The overall impression of the efficacy of pharmacological treatments for patients with chronic low back pain is rather sobering. The effects on pain reduction and improvement of function are commonly small to moderate and short lasting when compared to placebo. At the same time, the various types of drugs are not without side-effects. This holds especially true for serious side-effects associated with (prolonged) use of strong opioids. Future studies on patients with chronic back pain should aim to identify subgroups of patients with good response to specific pharmacological treatment to facilitate personalized care.

April 2017 Letter to the Editor-in-Chief

Letter to the Editor-in-Chief of JOSPT as follows: "Subgrouping Patients With Low Back Pain" with Authors' Response J Orthop Sports Phys Ther 2017;47(4):295. doi:10.2519/jospt.2017.0203.