Mechanisms-based classifications of musculoskeletal pain: part 1 of 3: symptoms and signs of central sensitisation in patients with low back (± leg) pain

Diagnostic accuracy of neurodynamic tests in upper-limb entrapment neuropathies: A systematic review and meta-analysis

BACKGROUND

Upper-limb neurodynamic tests are commonly used to diagnose neuropathies in this area, including cervical radiculopathy and carpal tunnel syndrome, although their diagnostic accuracy remains uncertain across different conditions and criteria.

OBJECTIVE

To assess the diagnostic accuracy of upper-limb neurodynamic tests and their variations and criteria for upper-limb entrapment neuropathies.

METHODS

A systematic review with meta-analysis was conducted in different databases (for their inception in February 2025), including studies evaluating the diagnostic accuracy of these tests. Sensitivity, specificity, likelihood ratios (LR), diagnostic odds ratios, diagnostic accuracy and the area under the curve (AUC) were calculated using a bivariate and univariate meta-analysis. The quality of evidence was evaluated using the GRADE approach, and meta-regression was performed to examine the influence of diagnostic criteria.

RESULTS

Twelve studies were included. Likelihood ratios for neuropathic pain conditions were LR+:1.65 and LR-:0.57, for cervical radiculopathy were LR+:2 and LR-:0.47, and for carpal tunnel syndrome were LR+:1.45 and LR-:0.66. The upper-limb neurodynamic test 2A showed the highest diagnostic accuracy (AUC: 0.76), with LR+:2.59 and LR-:0.42 for cervical radiculopathy, while test 3 had the highest specificity (0.92; LR+:7, LR-:0.48). Diagnostic accuracy for carpal tunnel syndrome was lower (AUC: 0.62). Meta-regression showed significant diagnostic criteria interaction, favoring structural differentiation maneuvers (p = 0.002).

CONCLUSION

Upper-limb neurodynamic tests show moderate sensitivity and low to moderate specificity for diagnosing upper-limb entrapment neuropathies, with diagnostic accuracy varying across conditions. The certainty of evidence ranges from very low to moderate, emphasizing the need for cautious clinical interpretation. Diagnostic reference criteria significantly influence test performance.

Manual therapy considerations for adhesive capsulitis in the breast cancer population: a clinical perspective

Adhesive capsulitis (AC) is common in women aged 40-60, overlapping with the population at higher risk for breast cancer. Many breast cancer survivors develop shoulder dysfunction, including AC, due to cancer treatments such as surgery, chemotherapy, and radiation, leading to pain, limited mobility, altered biomechanics, and soft tissue contracture. Despite the prevalence of AC in this population, clinical guidelines for its management remain underexplored. Manual therapy can play a key role in improving quality of life for these individuals.Understanding the pain mechanisms - nociceptive, neuropathic, and nociplastic - can inform appropriate treatment strategies for breast cancer survivors with AC. This clinical perspective integrates manual therapy principles into the evaluation and management of AC in this population. As breast cancer cases continue to rise, clinicians must recognize the impact of cancer treatment sequelae on orthopedic conditions to optimize patient care.

Application of Algorithm-Based Treatment Approach to Low Back Pain in the Emergency Department

Low back pain accounts for nearly 4 million annual emergency department (ED) visits, and patient outcomes following an ED visit for low back pain are poor. Additionally, only a small portion of patients visiting the ED for low back pain follow up with outpatient physical therapy within 3 months, despite established benefits of early versus delayed physical therapy referral such as improved patient outcomes, less opioid use, and reduced downstream health care utilization. Integrating a physical therapist directly into the ED care team can facilitate evidence-based guideline concordant care and improve patient outcomes, however, physical therapists who are staffed into this role from other settings may lack experience with evaluating and managing patients with acute low back pain. Additionally, there are several unique considerations of the ED care environment which may make existing treatment-based classification approaches difficult to apply in this setting, including physical constraints (eg, delivering care in stretchers and hallways), higher symptom severity and psychosocial stressors necessitating an emergency visit, and greater likelihood of alternative medical diagnoses (eg, kidney stone, aortic aneurysm) contributing to symptoms of low back pain. This perspective presents a modified ED treatment-based classification system (ED-TBC) for low back pain with 3 illustrative case examples. The ED-TBC for low back pain can be used to facilitate guideline concordant care, increase physical therapist confidence in evaluating low back pain in the ED, and reduce clinical practice variation.

Classifying Low Back Pain Through Pain Mechanisms: A Scoping Review for Physiotherapy Practice

Background: Low back pain (LBP) is a leading cause of disability worldwide, often driven by distinct pain mechanisms: nociceptive, neuropathic, and central sensitization. Accurate classification of these mechanisms is critical for guiding effective, targeted treatments. Methods: A scoping review was conducted following the Joanna Briggs Institute methodology and reported according to PRISMA-ScR guidelines. A comprehensive literature search was performed in MEDLINE, Cochrane CENTRAL, Scopus, PEDro, and Web of Science. Eligible studies included adults with LBP and focused on clinical criteria for classifying pain mechanisms. Data on study methods, population characteristics, and outcomes were extracted and synthesized. Results: Nine studies met the inclusion criteria. Nociceptive pain was characterized by localized symptoms proportional to mechanical triggers, with no neurological signs. Neuropathic pain was associated with burning sensations, dysaesthesia, and a positive neurodynamic straight leg raise (SLR) test. Central sensitization featured widespread pain, hyperalgesia, and disproportionate symptoms. Tools such as painDETECT, DN4, and the Central Sensitisation Inventory (CSI) were validated for neuropathic and central sensitization pain. Central sensitization and neuropathic pain were linked to greater disability and psychological distress compared to nociceptive pain. Conclusions: This review aims to provide a historical perspective on pain mechanism classifications and to explore how previous frameworks have influenced current diagnostic concepts in physiotherapy practice. By synthesizing key clinical criteria used to differentiate between nociceptive, neuropathic, and central sensitization pain, this review proposes a practical framework to improve the accuracy of pain classification in clinical settings.

The Influence of Pain Hypersensitivity and Psychological Factors on Pain and Disability in the Transition From Acute to Chronic Low Back Pain: A Longitudinal Exploratory Investigation and Cluster Analysis

Pain hypersensitivity is present in some people with acute low back pain (LBP) and thought to be involved in the development of chronic LBP. Early evidence suggests that pain hypersensitivity in acute LBP precedes poor long-term outcome. We aimed to examine whether the presence of pain hypersensitivity in acute LBP influenced recovery status at 6 months and differentiated how pain and disability changed over time. Participants with acute nonspecific LBP (<6 weeks after pain onset, N = 118) were included in this longitudinal study. Quantitative sensory testing, including pressure and heat pain thresholds, and conditioned pain modulation and questionnaires were compared at baseline and longitudinally (at 3 and 6 months) between recovered and unrecovered participants. Using k-means clustering, we identified subgroups based on baseline sensory measures alone, and in combination with psychological factors, and compared pain and disability outcomes between subgroups. Sensory measures did not differ at baseline or longitudinally between recovered (N = 50) and unrecovered (N = 68) participants. Subgrouping based on baseline sensory measures alone did not differentiate pain or disability outcomes at any timepoint. Participants with high psychological distress at baseline (N = 19) had greater disability, but not pain, at all timepoints than those with low psychological distress, regardless of the degrees of pain sensitivity. Our findings suggest that pain hypersensitivity in acute LBP does not precede poor recovery at 6 months or differentiate how pain and disability change over time. High psychological distress during acute LBP is associated with unremitting and pronounced disability, while pain severity is unaffected. PERSPECTIVE: Pain hypersensitivity is thought to be involved in the transition to chronic LBP. Contradictory to prevailing hypothesis, our findings suggest pain hypersensitivity alone in acute LBP does not precede poor recovery. High psychological distress in acute LBP has a stronger influence than pain hypersensitivity on long-term disability, but not pain outcomes.

Reduction of Chronic Primary Low Back Pain by Spinal Manipulative Therapy is Accompanied by Decreases in Segmental Mechanical Hyperalgesia and Pain Catastrophizing: A Randomized Placebo-controlled Dual-blind Mixed Experimental Trial

Chronic primary low back pain (CPLBP) refers to low back pain that persists over 3 months, that cannot be explained by another chronic condition, and that is associated with emotional distress and disability. Previous studies have shown that spinal manipulative therapy (SMT) is effective in relieving CPLBP, but the underlying mechanisms remain elusive. This randomized placebo-controlled dual-blind mixed experimental trial (NCT05162924) aimed to investigate the efficacy of SMT to improve CPLBP and its underlying mechanisms. Ninety-eight individuals with CPLBP and 49 controls were recruited. Individuals with CPLBP received SMT (n = 49) or a control intervention (n = 49), 12 times over 4 weeks. The primary outcomes were CPLBP intensity (0-100 on a numerical rating scale) and disability (Oswestry Disability Index). Secondary outcomes included pressure pain thresholds in 4 body regions, pain catastrophizing, Central Sensitization Inventory, depressive symptoms, and anxiety scores. Individuals with CPLBP showed widespread mechanical hyperalgesia (P < .001) and higher scores for all questionnaires (P < .001). SMT reduced pain intensity compared with the control intervention (mean difference: -11.7 [95% confidence interval, -11.0 to -12.5], P = .01), but not disability (P = .5). Similar mild to moderate adverse events were reported in both groups. Mechanical hyperalgesia at the manipulated segment was reduced after SMT compared with the control intervention (P < .05). Pain catastrophizing was reduced after SMT compared with the control intervention (P < .05), but this effect was not significant after accounting for changes in clinical pain. Although the reduction of segmental mechanical hyperalgesia likely contributes to the clinical benefits of SMT, the role of pain catastrophizing remains to be clarified. PERSPECTIVE: This randomized controlled trial found that 12 sessions of SMT yield greater relief of CPLBP than a control intervention. These clinical effects were independent of expectations, and accompanied by an attenuation of hyperalgesia in the targeted segment and a modulation of pain catastrophizing.

Pain neuroscience education improves post-traumatic stress disorder, disability, and pain self-efficacy in veterans and service members with chronic low back pain: Preliminary results from a randomized controlled trial with 12-month follow-up

Post-traumatic stress disorder (PTSD) and chronic low back pain (CLBP) are frequently co-morbid. Some research suggests that PTSD and CLBP may share common neurobiological mechanisms related to stress. Traditional biomedical education may be ineffective for PTSD and CLBP, especially when co-morbid. The purpose of this study is to determine if pain neuroscience education (PNE) is more effective than traditional education in reducing PTSD, disability, pain, and maladaptive beliefs in patients with CLBP. Participants with CLBP and possible PTSD/PTSD-symptoms were recruited for this study. Participants were randomly allocated to a PNE group or a traditional education group. The intervention included 30 minutes of education followed by a standardized exercise program once a week for 4-weeks with a 4 and 8-week follow-up and healthcare utilization assessed at 12-months. Forty-eight participants consented for this research study with 39 allocated to treatment (PNE n = 18, traditional n = 21). PNE participants were more likely to achieve a clinically meaningful reduction in PTSD symptoms and disability at short-term follow-up. At 12-months, the PNE group utilized healthcare with 76% lower costs. In participants with CLBP, PNE may reduce hypervigilance toward pain and improve PTSD symptoms. Participants who received PNE were more confident body-tissues were safe to exercise. These beliefs about pain could contribute to a decrease in perceived disability and healthcare consumption for CLBP.

Pain Neuroscience Education for Acute Pain

In musculoskeletal and sports medicine, pain has traditionally been linked to tissue injury, often assuming a linear correlation between tissue damage and pain intensity. However, modern pain science has illuminated the complexity of the human pain experience, incorporating psychosocial elements, nervous system sensitization, immune responses, and structural changes in the brain as factors. This contemporary understanding of pain has proven highly beneficial for both clinicians treating individuals in pain and those experiencing pain. Pain neuroscience education (PNE) provides individuals in pain with an understanding of the underlying neurobiology and neurophysiology of their pain experience, which has been shown to result in decreased self-reported pain, reduced disability, the alleviation of fear and fear-avoidance behaviors, diminished pain catastrophizing, and improved movement. Currently, research on PNE predominantly focuses on interventions with individuals with persistent or chronic pain conditions. However, those who experience acute, sub-acute, and perioperative pain also have the potential for elevated levels of fear, fear-avoidance, and pain catastrophizing, indicating potential benefits from PNE. This invited commentary seeks to inform readers about the latest advancements in pain science and propose a conceptual model for delivering PNE in acute pain experiences.

Level of Evidence

5.

Evaluation of Central Sensitisation in Bladder Pain Syndrome: A Systematic Review

INTRODUCTION AND HYPOTHESIS

Bladder pain syndrome (BPS) is a debilitating condition characterised by exaggerated bladder sensations and altered bladder function. It is still unknown whether the condition is a peripheral sensory problem or due to abnormal central sensory processing as seen in central sensitisation. This systematic review, which followed a published and Prospective Register of Systematic Reviews-registered protocol (CRD42021229962), is aimed at establishing the scope of central sensitisation in patients with BPS to aid optimal management and treatment.

METHODS

Four databases were searched, and appraisal of the identified studies was conducted by two independent reviewers based on eligibility criteria: patients with BPS being investigated for central sensitisation with or without comparison of controls, English-language articles, full text and publication in a peer-reviewed journal. The Methodological Index for non-Randomised Studies was used to determine study quality. We identified 763 papers in total, with 15 studies included in the final analysis. All studies were observational and had a low risk of bias. Measures included in the evaluation of CS were questionnaires, urodynamics, and quantitative sensory testing methods.

RESULTS

There was evidence of central sensitisation in patients with BPS in all papers evaluated (15 out of 15). In addition, more significant central sensitisation correlated with severe disease presentation (3 out of 3 papers) and concomitant chronic pain conditions (5 out of 5 papers).

CONCLUSIONS

Central sensitisation plays an integral role in BPS patient pathology. Many secondary measures are used to evaluate this condition. Stratification of patients based on their pathology (peripheral, central or a combination of the two) will aid in implementing an individualised management strategy.

Nociceptive, neuropathic, or nociplastic low back pain? The low back pain phenotyping (BACPAP) consortium's international and multidisciplinary consensus recommendations

The potential to classify low back pain as being characterised by dominant nociceptive, neuropathic, or nociplastic mechanisms is a clinically relevant issue. Preliminary evidence suggests that these low back pain phenotypes might respond differently to treatments; however, more research must be done before making specific recommendations. Accordingly, the low back pain phenotyping (BACPAP) consortium was established as a group of 36 clinicians and researchers from 13 countries (five continents) and 29 institutions, to apply a modified Nominal Group Technique methodology to develop international and multidisciplinary consensus recommendations to provide guidance for identifying the dominant pain phenotype in patients with low back pain, and potentially adapt pain management strategies. The BACPAP consortium's recommendations are also intended to provide direction for future clinical research by building on the established clinical criteria for neuropathic and nociplastic pain. The BACPAP consortium's consensus recommendations are a necessary early step in the process to determine if personalised pain medicine based on pain phenotypes is feasible for low back pain management. Therefore, these recommendations are not ready to be implemented in clinical practice until additional evidence is generated that is specific to these low back pain phenotypes.

Understanding How Patients With Lumbar Radiculopathy Make Sense of and Cope With Their Symptoms

Lumbar radiculopathy, characterized by pain radiating along a nerve root, significantly diminishes the quality of life due to its neuropathic nature. Patients' understanding of their illness and the coping strategies they employ directly influence how they manage their condition. Understanding these illness representations from the patient's perspective is crucial for healthcare providers seeking to optimize treatment outcomes. This study adopted a qualitative interpretive/constructive paradigm to explore this dynamic. A qualitative evidence synthesis approach, utilizing best-fit framework synthesis for data extraction, was applied to analyze primary qualitative studies focused on patient experiences with lumbar radiculopathy. Using SPiDER (Sample, Phenomenon of interest, Design, Evaluation, Research type) to guide the search strategy, extracted data was mapped against the Common-Sense Model of Self-Regulation (CSM) framework. Sixteen studies, with moderate to minor methodological quality concerns, were included in the analysis. Data mapping across CSM domains generated 14 key review findings. Results suggest that patients with high-threat illness representations often exhibit maladaptive coping behaviors (e.g., activity avoidance) driven by emotional responses. In contrast, problem-solving techniques appear to contribute to positive outcomes (e.g., exercise adherence and effective self-management) in patients who perceive their condition as less threatening. These findings highlight the potential benefits of interventions designed to reduce perceived threat levels and enhance self-efficacy in patients with lumbar radiculopathy, leading to improved self-management and ultimately better health outcomes.

Management of chronic musculoskeletal pain in an adult with Down syndrome using a modified pain neuroscience approach: a case report

BACKGROUND

The use of pain neuroscience education (PNE) in the management of chronic musculoskeletal pain is well documented in the literature for the adult population. However, the use of this component within the larger biopsychosocial approach has not been examined in adults with intellectual disabilities. The purpose of this case report is to describe the utilization of a PNE approach combined with exercise in the physical therapy management of chronic musculoskeletal pain in an adult with Down syndrome.

CASE DESCRIPTION

The patient was a 40-year-old man with Down syndrome who presented with chronic low back pain that affected his sleep, participation at work, and social activities. Modified metaphors were used to assist the patient in understanding his pain experience as part of a multi-modal program that included exercise and aquatic therapy.

OUTCOMES

Upon concluding 11 weeks of treatment, the patient returned to his prior work schedule and social activities with a pain rating at worst of 3/10 on the numeric pain rating scale with only occasional pain episodes. His disability score on the Oswestry Disability Index improved by 39% relative to baseline.

DISCUSSION

The findings demonstrate how utilizing PNE within a physical therapy plan of care was used in the management of chronic musculoskeletal pain to improve function in an adult with Down syndrome.

Association of central sensitization, visceral fat, and surgical outcomes in lumbar spinal stenosis

BACKGROUND

Controversy remains regarding predictors of surgical outcomes for patients with lumbar spinal stenosis (LSS). Pain sensitization may be an underlying mechanism contributing to LSS surgical outcomes. Further, obesity is associated with dissatisfaction and poorer outcomes after surgery for LSS. Therefore, this study aimed to examine the relationship between central sensitization (CS), visceral fat, and surgical outcomes in LSS.

METHODS

Patients with LSS were categorized based on their central sensitization inventory (CSI) scores into low- (CSI < 40) and high- (CSI ≥ 40) CSI subgroups. The participants completed clinical outcome assessments preoperatively and 12 months postoperatively.

RESULTS

Overall, 60 patients were enrolled in the study (28 men, 32 women; mean age: 62.1 ± 2.8 years). The high-CSI group had significantly higher mean low back pain (LBP), leg pain, and leg numbness visual analogue scale (VAS) scores than the low-CSI group (p < 0.01). The high-CSI group had a significantly higher mean visceral fat area than the low-CSI group (p < 0.01). Postoperatively, LBP VAS score was significantly worse in the high-CSI group. Relative to preoperatively, postoperative leg pain and leg numbness improved significantly in both groups.

CONCLUSIONS

We believe that neuro decompression can be effective for LSS surgical outcomes in patients with CS; nonetheless, it should be approached with caution owing to the potential for worsening LBP. Additionally, visceral fat is an important indicator suggesting the involvement of CS.

Physiotherapy management of nociplastic pain: A Delphi study of Italian specialists

BACKGROUND AND PURPOSE

Nociplastic pain due to central sensitization (CS) is common in people suffering from chronic pain, but no clinical practice guideline is available in rehabilitative settings for patients' management. The aim of this study is to achieve expert consensus on physiotherapy competencies in the management of people with nociplastic pain and suspected CS mechanisms.

METHODS

A web-based Delphi process was employed. Experts in the rehabilitation field were recruited following pre-defined eligibility criteria. Following completion of three Delphi rounds, the final list of competencies was generated.

RESULTS

In all, 23 participants were recruited. They all completed Round 1 (23/23, 100%), twenty Round 2 and Round 3 (20/23, 87%). Following Round 1, seven areas were identified by the panel as crucial for CS physiotherapy management; 19 competencies out of 40 reached the consensus between experts, and nine additional competencies were added to Round 2 following literary review. Round 2 identified the agreement for all the 29 competencies. During Round 3, all the experts confirmed the final list generated through the consensus process.

DISCUSSION

An agreement between experts was found for the final list of competencies that a physiotherapist should implement every time it approaches people with suspected CS mechanisms. Further research is needed to support the clinical utility of our findings and their applicability in daily practice.

Care for the patient with low back pain

ABSTRACT

Low back pain (LBP) continues to be one of the most common conditions leading patients to seek medical care globally. The NP is on the frontline, playing an integral role in caring for patients with LBP. Understanding the etiology of LBP is essential in the treatment.

Central sensitization in CRPS patients with widespread pain: a cross-sectional study

OBJECTIVE

Widespread pain hypersensitivity and enhanced temporal summation of pain (TSP) are commonly reported in patients with complex regional pain syndrome (CRPS) and discussed as proxies for central sensitization. This study aimed to directly relate such signs of neuronal hyperexcitability to the pain phenotype of CRPS patients.

METHODS

Twenty-one CRPS patients and 20 healthy controls (HC) were recruited. The pain phenotype including spatial pain extent (assessed in % body surface) and intensity were assessed and related to widespread pain hypersensitivity, TSP, and psychological factors. Quantitative sensory testing (QST) was performed in the affected, the contralateral and a remote (control) area.

RESULTS

CRPS patients showed decreased pressure pain thresholds in all tested areas (affected: t(34)  = 4.98, P < .001, contralateral: t(35) = 3.19, P = .005, control: t(31) = 2.65, P = .012). Additionally, patients showed increased TSP in the affected area (F(3,111) = 4.57, P = .009) compared to HC. TSP was even more enhanced in patients with a high compared to a low spatial pain extent (F(3,51) = 5.67, P = .008), suggesting pronounced spinal sensitization in patients with extended pain patterns. Furthermore, the spatial pain extent positively correlated with the Bath Body Perception Disturbance Scale (ρ = 0.491; P = .048).

CONCLUSIONS

Overall, we provide evidence that the pain phenotype in CRPS, that is, spatial pain extent, might be related to sensitization mechanism within the central nociceptive system. This study points towards central neuronal excitability as a potential therapeutic target in patients with more widespread CRPS.

The Biology of Chronic Pain and Its Implications for Pain Neuroscience Education: State of the Art

Pain is an individualized experience for the person suffering from chronic pain. Significant strides have been made in the last few decades in understanding various biological changes that coincide with chronic pain. This state-of-the-art overview looks at the current evidence related to the biology of chronic pain and the implications these findings have on the delivery of pain neuroscience education (PNE). The paper summarizes the various (epi)genetic, neural, endocrine, and immune factors discovered and explored in the scientific literature concerning chronic pain. Each of these biological factors has various implications for the content and delivery of PNE. We discuss the future directions these biological factors have for the clinical implementation of PNE by linking the importance of behavior change, optimizing the learning environment, and using an individualized multimodal treatment approach with PNE. In addition, future directions for research of PNE based on these biological factors are provided with importance placed on individualized patient-centered care and how PNE can be used with traditional modes of care and growing trends with other care methods. PNE was originally and continues to be rooted in understanding chronic pain biology and how that understanding can improve patient care and outcomes.

Socioeconomic status, mental health, and nutrition are the principal traits for low back pain phenotyping: Data from the osteoarthritis initiative

Background

Low back pain (LBP) is a heterogeneous disease with biological, physical, and psychosocial etiologies. Models for predicting LBP severity and chronicity have not made a clinical impact, perhaps due to difficulty deciphering multidimensional phenotypes. In this study, our objective was to develop a computational framework to comprehensively screen metrics related to LBP severity and chronicity and identify the most influential.

Methods

We identified individuals from the observational, longitudinal Osteoarthritis Initiative cohort (N = 4796) who reported LBP at enrollment (N = 215). OAI descriptor variables (N = 1190) were used to cluster individuals via unsupervised learning and uncover latent LBP phenotypes. We also developed a dimensionality reduction algorithm to visualize clusters/phenotypes using Uniform Manifold Approximation and Projection (UMAP). Next, to predict chronicity, we identified those with acute LBP (N = 40) and persistent LBP over 8 years of follow-up (N = 66) and built logistic regression and supervised machine learning models.

Results

We identified three LBP phenotypes: a "high socioeconomic status, low pain severity group", a "low socioeconomic status, high pain severity group", and an intermediate group. Mental health and nutrition were also key clustering variables, while traditional biomedical factors (e.g., age, sex, BMI) were not. Those who developed chronic LBP were differentiated by higher pain interference and lower alcohol consumption (a correlate to poor physical fitness and lower soceioeconomic status). All models for predicting chronicity had satisfactory performance (accuracy 76%-78%).

Conclusions

We developed a computational pipeline capable of screening hundreds of variables and visualizing LBP cohorts. We found that socioeconomic status, mental health, nutrition, and pain interference were more influential in LBP than traditional biomedical descriptors like age, sex, and BMI.

Human assumed central sensitization in people with acute non-specific low back pain: A cross-sectional study of the association with brain-derived neurotrophic factor, clinical, psychological and demographic factors

BACKGROUND

Early evidence suggests human assumed central sensitization (HACS) is present in some people with acute low back pain (LBP). Factors influencing individual variation in HACS during acute LBP have not been fully explored. We aimed to examine the evidence for HACS in acute LBP and the contribution of brain-derived neurotrophic factor (BDNF), clinical, psychological and demographic factors to HACS.

METHODS

Participants with acute LBP (<6 weeks after pain onset, N = 118) and pain-free controls (N = 57) from a longitudinal trial were included. Quantitative sensory testing including pressure and heat pain thresholds and conditioned pain modulation, BDNF serum concentration and genotype and questionnaires were assessed.

RESULTS

There were no signs of HACS during acute LBP at group level when compared with controls. Sensory measures did not differ when compared between controls and LBP participants with different BDNF genotypes. Two LBP subgroups with distinct sensory profiles were identified. Although one subgroup (N = 60) demonstrated features of HACS including pressure/heat pain hypersensitivity at a remote site and deficient conditioned pain modulation, pain severity and disability did not differ between the two subgroups. Variation in sensory measures (~33%) was partially explained by BDNF genotype, sex, age and psychological factors.

CONCLUSIONS

This study confirms that HACS is present in some people with acute LBP, but this was not associated with pain or disability. Further, no relationship was observed between BDNF and HACS in acute LBP. More research is needed to understand factors contributing to individual variation in sensory measures in LBP.

SIGNIFICANCE

Human assumed central sensitization (HACS) is present in acute low back pain (LBP) but factors contributing to individual variation are not fully explored. This study investigated the relationship between factors such as brain derived neurotrophic factor (BDNF) and HACS in acute LBP. Our findings indicate that HACS was present in specific LBP subgroups but BDNF was unrelated to HACS. Combinations of BDNF genotype, demographic and psychological factors explained a small proportion of the variation in sensory measures during acute LBP.

Prevalence and associated factors of myofascial pain in orthognathic patients with skeletal class II malocclusion

Orthognathic patients with skeletal class II malocclusion frequently suffer from myofascial pain (MP).

PURPOSE

This study aimed to evaluate the prevalence and associated factors of MP in these patients.

METHODS

This cross-sectional study was performed in adult patients with skeletal Class II malocclusion requiring orthognathic surgery. They were divided according to the presence or absence of MP. The predictor variables were craniofacial morphology, sex, temporomandibular disorders, chronic pain, depression, and polymorphisms of dopamine receptors DRD2 (rs6275 and rs6276) and ANKK1 (rs1800497) genes. Data were submitted to statistical analyses using the linear regression model and Poisson regression with a significance level of 0.05.

RESULTS

Sixty-five individuals were selected, of which 50 (76.92%) were females. A total of 21 (32.3%) patients had MP. Individuals with MP showed a decrease in the mandible gonial angle (p = 0.042) and an increased risk of having temporomandibular joint (TMJ) disc displacement (p = 0.003), TMJ pain (p = 0.030), chronic pain (p = 0.001), and severe depression (p = 0.015). Additionally, individuals carrying AA and AG genotypes in rs6275, and CC genotype in rs6276, were more likely to have MP (p < 0.05).

CONCLUSION

In this study, 32.3% of skeletal class II orthognathic patients had MP, which was associated with a decreased gonial angle, TMJ disc displacement, TMJ pain, chronic pain, depression, and polymorphisms in the DRD2 gene.

Assessment of exercise-induced hypoalgesia in chronic low back pain and potential associations with psychological factors and central sensitization symptoms: A case-control study

INTRODUCTION

Exercise is the most recommended treatment for chronic low back pain (CLBP) and is effective in reducing pain, but the mechanisms underlying its effects remain poorly understood. Exercise-induced hypoalgesia (EIH) may play a role and is thought to be driven by central pain modulation mechanisms. However, EIH appears to be disrupted in many chronic pain conditions and its presence in people with CLBP remains unclear. As people suffering from chronic pain often exhibit psychological factors and central sensitization symptoms influencing pain perception, EIH might be associated with these factors.

OBJECTIVE

The aim of this study is to compare the level of EIH between participants with and without CLBP following back and wrist exercises and to assess the associations between EIH, psychological factors, and symptoms of central sensitization (using the central sensitization inventory - CSI) in CLBP.

METHOD

Twenty-eight participants with CLBP and 23 without pain were recruited. Pressure pain thresholds (PPT) were measured at 4 sites (2 bony sites = capitate, S1|2 muscle sites = wrist flexors, lumbar erector spinae) before and after each of two exercises (wrist flexion and lumbar extension). Exercise-induced hypoalgesia was defined as percent change in PPT from pre- to post-exercise. Participants with CLBP also completed questionnaires to measure psychological factors (e.g., kinesiophobia, catastrophizing, anxiety, and self-efficacy) and symptoms of central sensitization (CSI), and correlations with EIH were calculated.

RESULTS

After wrist exercise, EIH measured at the muscle sites was lower in the CLBP group compared with the pain-free group (p = 0.047) but no differences were found at bony sites (p = 0.49). No significant differences for EIH were observed following back exercise at muscle sites (p = 0.14) or at bony sites (p = 0.65). Exercise-induced hypoalgesia was not correlated with any psychological factors or with the CSI score.

CONCLUSION

The lower EIH following wrist exercises may represent an alteration in pain modulation control in CLBP. However, psychological factors and central sensitization symptoms may not explain the differences observed.

Mechanisms of chiropractic spinal manipulative therapy for patients with chronic primary low back pain: protocol for a mechanistic randomised placebo-controlled trial

INTRODUCTION

Chronic low back pain (CLBP) is a highly prevalent and disabling condition. Identifying subgroups of patients afflicted with CLBP is a current research priority, for which a classification system based on pain mechanisms was proposed. Spinal manipulative therapy (SMT) is recommended for the management of CLBP. Yet, little data are available regarding its mechanisms of action, making it difficult to match this intervention to the patients who may benefit the most. It was suggested that SMT may influence mechanisms associated with central sensitisation. Therefore, classifying patients with CLBP according to central sensitisation mechanisms may help predict their response to SMT.

METHODS AND ANALYSIS

This protocol describes a randomised placebo-controlled trial aiming to examine which variables linked to central sensitisation may help predict the clinical response to SMT in a cohort of patients with CLBP. One hundred patients with chronic primary low back pain will be randomised to receive 12 sessions of SMT or placebo SMT over a 4-week period. Pain intensity and disability will be assessed as primary outcomes after completing the 4-week treatment (primary endpoint), and at 4-week and 12-week follow-ups. Baseline values of two pain questionnaires, lumbar pressure pain thresholds, concentrations of an inflammatory cytokine and expectations of pain relief will be entered as predictors of the response to SMT in a multiple regression model. Changes in these variables after treatment will be used in a second multiple regression model. The reference values of these predictors will be measured from 50 age and sex-matched healthy controls to allow interpretation of values in patients. Mixed analyses of variance will also be conducted to compare the primary outcomes and the predictors between groups (SMT vs placebo) over time (baseline vs post-treatment).

ETHICS AND DISSEMINATION

Ethical approval was granted by the Fundación Jiménez Díaz Clinical Research Ethics Committee.

TRIAL REGISTRATION NUMBER

NCT05162924.

Indicators of central sensitization in chronic neuropathic pain after spinal cord injury

BACKGROUND

Central sensitization is considered a key mechanism underlying neuropathic pain (NP) after spinal cord injury (SCI).

METHODS

Two novel proxies for central sensitization were investigated in thoracic SCI subjects with (SCI-NP) and without NP (SCI-nonNP) compared to healthy controls (HC). Specifically, temporal summation of pain (TSP) was investigated by examining pain ratings during a 2-min tonic heat application to the volar forearm. Additionally, palmar heat-induced sympathetic skin responses (SSR) were recorded in order to reveal changes in pain-autonomic interaction above the lesion level. Pain extent was assessed as the percentage of the body area and the number of body regions being affected by NP.

RESULTS

Enhanced TSP was observed in SCI-NP (+66%) compared to SCI-nonNP (-75%, p = 0.009) and HC (-59%, p = 0.021). In contrast, no group differences were found (p = 0.685) for SSR habituation. However, pain extent in SCI-NP was positively correlated with deficient SSR habituation (body area: r = 0.561, p = 0.024; body regions: r = 0.564, p = 0.023).

CONCLUSIONS

These results support the value of TSP and heat-induced SSRs as proxies for central sensitization in widespread neuropathic pain syndromes after SCI. Measures of pain-autonomic interaction emerged as a promising tool for the objective investigation of sensitized neuronal states in chronic pain conditions.

SIGNIFICANCE

We present two surrogate readouts for central sensitization in neuropathic pain following SCI. On the one hand, temporal summation of tonic heat pain is enhanced in subjects with neuropathic pain. On the other hand, pain-autonomic interaction reveals potential advanced measures in chronic pain, as subjects with a high extent of neuropathic pain showed diminished habituation of pain-induced sympathetic measures. A possible implication for clinical practice is constituted by an improved assessment of neuronal hyperexcitability potentially enabling mechanism-based treatment.

Associations between visceral fat chronic low back pain and central sensitization in patients with lumbar spinal stenosis

BACKGROUND

Pain sensitization may be one of the mechanisms contributing to chronic low back pain (CLBP).

OBJECTIVE

To evaluate the association between visceral fat, CLBP, and central sensitization (CS); describe the relationship between low back pain (LBP) intensity and CS; and identify possible correlation between visceral fat and LBP intensity.

METHODS

Patients with CLBP were divided using their CS inventory (CSI) scores into low- (CSI < 40) and high-CSI (CSI ⩾ 40) subgroups. We compared computed tomography (CT) measurements and scores for association with pain according to the visual analogue scale (VAS) between the two groups.

RESULTS

The low-CSI and the high-CSI groups had 47 patients (67.1%; 21 men, 26 women) and 23 patients (32.9%; 11 men and 12 women), respectively. The high-CSI group had a significantly higher mean VAS score (p< 0.01) and estimated mean visceral fat area (p< 0.05) than the low-CSI group. There was a moderate positive correlation between VAS score and visceral fat (standardised partial regression coefficient: 0.659, p< 0.01) in the high-CSI group according to multiple linear regression analysis adjusted for age and sex.

CONCLUSIONS

Visceral fat is associated with CLBP, regardless of sex or age, and may be a potential therapeutic target for CLBP with CS.

Structural insight into apelin receptor-G protein stoichiometry

The technique of cryogenic-electron microscopy (cryo-EM) has revolutionized the field of membrane protein structure and function with a focus on the dominantly observed molecular species. This report describes the structural characterization of a fully active human apelin receptor (APJR) complexed with heterotrimeric G protein observed in both 2:1 and 1:1 stoichiometric ratios. We use cryo-EM single-particle analysis to determine the structural details of both species from the same sample preparation. Protein preparations, in the presence of the endogenous peptide ligand ELA or a synthetic small molecule, both demonstrate these mixed stoichiometric states. Structural differences in G protein engagement between dimeric and monomeric APJR suggest a role for the stoichiometry of G protein-coupled receptor- (GPCR-)G protein coupling on downstream signaling and receptor pharmacology. Furthermore, a small, hydrophobic dimer interface provides a starting framework for additional class A GPCR dimerization studies. Together, these findings uncover a mechanism of versatile regulation through oligomerization by which GPCRs can modulate their signaling.

Reliability of the straight leg raise test for suspected lumbar radicular pain: A systematic review with meta-analysis

BACKGROUND

The passive straight leg raise (SLR) and crossed SLR are recommended tests for lumbar radicular pain. There are no recent reviews of test reliability.

OBJECTIVES

To summarize SLR and crossed SLR reliability in patients with suspected lumbar radicular pain.

DESIGN

Systematic review with meta-analysis.

METHOD

MEDLINE and CINAHL were searched for studies published before April 2021 that reported SLR or crossed SLR reliability in patients with low back-related leg pain. Supplemental analyses also included patients with low back pain only. Study selection, risk of bias assessment (QAREL), and data extraction were performed in duplicate. Kappa, intraclass correlation coefficients, and smallest detectable difference (SDD₉₅) quantified reliability. Meta-analysis was performed when appropriate. Confidence in the evidence was determined by applying GRADE principles.

RESULTS/FINDINGS

Fifteen studies met selection criteria. One-hundred-eighty-nine participants had low back-related leg pain. Four-hundred-thirty-nine were included in supplemental analyses. Meta-analyses showed at least fair inter-rater reliability when a positive SLR required provocation of lower extremity symptoms or pain. SLR reliability was at least moderate when testing included structural differentiation (e.g., ankle dorsiflexion). A low prevalence of positive crossed SLR tests led to wide-ranging reliability estimates. Confidence in the evidence for identifying a positive SLR or crossed SLR was moderate to very low. SDD₉₅ values for different raters measuring SLR range of motion ranged from 13 to 20°.

CONCLUSIONS

Reliability data support testing SLR with structural differentiation manoeuvres. Crossed SLR reliability data are inconclusive. Measurement error likely prohibits using SLR range of motion for clinical decision-making.

Questionnaire-based somatosensory profiling in breast cancer survivors: are we there yet? Associations between questionnaires and quantitative sensory testing

PURPOSE

Pain and sensory disturbances are common side effects of breast cancer treatment. Differential somatosensory functioning may reflect distinct pathophysiological backgrounds and therapeutic needs. Aim was to examine whether questionnaires evaluating signs and symptoms related to somatosensory functioning correlate sufficiently with quantitative sensory testing (QST) in breast cancer survivors to warrant consideration for somatosensory profiling in clinical practice.

METHODS

One year after breast cancer surgery, 147 women underwent QST and completed following questionnaires: Douleur Neuropathique en 4 questions (DN4), Central Sensitization Inventory, Margolis Pain Diagram and Visual Analog Scales (VAS). Associations between the questionnaires and QST were evaluated using Spearman correlation coefficients (rs).

RESULTS

Significant but weak (rs < 0.30) correlations were found between total DN4 score and QST results at the inner upper arm for detection of sharp stimuli (rs = 0.227), cold stimuli (rs = -0.186), and painful heat stimuli (rs = 0.179), as well as between QST evaluating conditioned pain modulation and the Margolis Pain Diagram on one hand (rs = 0.176) and minimum-maximum pain intensity differences (VAS) on the other (rs = -0.170).

CONCLUSION

Questionnaires evaluating signs and symptoms related to somatosensory functioning are insufficient for somatosensory profiling. Although somatosensory profiling may be valuable in a mechanism-based management, more research on the most appropriate clinical tools is needed.IMPLICATIONS FOR REHABILITATIONClinicians should be able to recognize that patients with persistent pain or sensory disturbances following breast cancer surgery may have a component of altered somatosensory processing as a significant contributor to their complaint in order to address it appropriately.Somatosensory profiling has yet to be implemented into clinical practice.No evidence-based recommendations can be made on the use of self-reported questionnaires to assess somatosensory processing in a breast cancer population based on the findings of this study.It is suggested to combine information on how individuals process and experience somatosensory stimulation with information from the patient interview or questionnaires to consider which biological, psychological and/or social factors may drive or sustain these neurophysiological processes.

An observational study of centrally facilitated pain in individuals with chronic low back pain

Introduction

Central pain facilitation can hinder recovery in people with chronic low back pain (CLBP).

Objectives

The objective of this observational study was to investigate whether indices of centrally facilitated pain are associated with pain outcomes in a hospital-based cohort of individuals with CLBP undertaking a pain management programme.

Methods

Participants provided self-report and pain sensitivity data at baseline (n = 97) and again 3 months (n = 87) after a cognitive behavioural therapy-based group intervention including physiotherapy. Indices of centrally facilitated pain were pressure pain detection threshold, temporal summation and conditioned pain modulation at the forearm, Widespread Pain Index (WPI) classified using a body manikin, and a Central Mechanisms Trait (CMT) factor derived from 8 self-reported characteristics of anxiety, depression, neuropathic pain, fatigue, cognitive dysfunction, pain distribution, catastrophizing, and sleep. Pain severity was a composite factor derived from Numerical Rating Scales. Cross-sectional and longitudinal regression models were adjusted for age and sex.

Results

Baseline CMT and WPI each was associated with higher pain severity (CMT: r = 0.50, P < 0.001; WPI: r = 0.21, P = 0.04) at baseline and at 3 months (CMT: r = 0.38, P < 0.001; WPI: r = 0.24, P = 0.02). High baseline CMT remained significantly associated with pain at 3 months after additional adjustment for baseline pain (β = 2.45, P = 0.04, R 2 = 0.25, P < 0.0001). Quantitative sensory testing indices of pain hypersensitivity were not significantly associated with pain outcomes at baseline or at 3 months.

Conclusion

Central mechanisms beyond those captured by quantitative sensory testing are associated with poor CLBP outcome and might be targets for improved therapy.

Nonoperative treatment for pain sensitization in patients with low back pain: protocol for a systematic review

BACKGROUND

Low back pain is a disability that occurs worldwide. It is a heterogeneous disorder that affects patients with dominant nociceptive, neuropathic, and central sensitization pain. An important pathophysiology of low back pain involves pain sensitization. Various nonoperative interventions are available for treatment, but there is inconclusive evidence on the effectiveness of these interventions for pain sensitization, leading to arbitrary nonoperative treatments for low back pain.

METHODS

We will conduct a systematic review of RCTs evaluating the effectiveness and safety of nonoperative treatment for pain sensitization in patients with low back pain. The primary outcomes will be static quantitative sensory testing, dynamic quantitative sensory testing, and pain algometry. The secondary outcome will be adverse events. We will search the PubMed, Embase, Scopus, Web of Science, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Cochrane Central Register of Controlled Trials (CENTRAL), and Cochrane Library databases. Two independent authors will screen the titles and abstracts, review full texts, extract data, assess the risk of bias, and evaluate the quality of evidence. We will qualitatively and quantitatively synthesize the results using a random effects model for meta-analysis.

DISCUSSION

This systematic review aims to provide evidence regarding which treatment, if any, provides the greatest benefit for pain sensitization and safety among patients with low back pain. Evidence synthesized from this systematic review will inform clinical practice and further research. Since there is still a small amount of research, additional studies might need to be conducted in the future.

SYSTEMATIC REVIEW REGISTRATION

Submitted to PROSPERO on March 20, 2021, CRD42021244054.

MATLAB Analysis of SP Test Results—An Unusual Parasympathetic Nervous System Activity in Low Back Leg Pain: A Case Report

The Skorupska Protocol (SP) test is a new validated tool used to confirm nociplastic pain related to muscles based on a pathological autonomic nervous system (ANS) activity due to muscle nociceptive noxious stimulation analyzed automatically. Two types of amplified vasomotor response are defined as possible: vasodilatation and vasoconstriction. Until now, amplified vasodilatation among low back leg pain and/or sciatica subjects in response to the SP test was confirmed. This case report presents an unusual vasomotor response to the SP test within the pain zone of a sciatica-like case. Conducted twice, the SP test confirmed amplified vasoconstriction within the daily complaint due to noxiously stimulated muscle-referred pain for the first time. Additionally, a new type of the SP test analysis using MATLAB was presented. The SP test supported by MATLAB seems to be an interesting solution to confirm nociplastic pain related to muscles based on the pathological autonomic reactivity within the lower leg back pain zone. Further studies using the SP test supported by MATLAB are necessary to compare the SP test results with the clinical state and other types of nociplastic pain examination.

Mechanical Needling with Sterile Water versus Steroids Injection for Facet Joint Syndrome: A Retrospective Observational Study

Objective. This present study aimed to explore the clinical effects of ultrasound-guided (USG) mechanical needling with sterile water injection for lumbar facet joint syndrome. Methods. This was a retrospective cohort study that assessed the clinical outcome of ageing patients who received USG mechanical needling with sterile water injection. In addition, the clinical outcome of age- and gender-matched patients randomly selected from patients who received mechanical needling with sterile water was compared to the patients injected with steroids in a 2 : 1 ratio. The data were extracted from the medical records of ageing patients with facet joint syndrome who received USG injection at the lumbosacral spine by the first author. Low back pain or axial pain, and leg pain or radicular pain were assessed by the visual analogue scale (VAS), and gait ability with walking distance was obtained at 6 different time points. Results. A total of 4,276 medical records were examined. Four thousand two hundred twenty-eight ageing patients received needling with sterile water injection and found that the efficacy lasted up to 6 months. Ninety-six patients were compared with 48 patients who received steroid injection. Those who received steroids had less back and leg pain at 1 week after injection; however, pain returned at 3 months and 6 months after injection. Conclusions. USG mechanical needling with sterile water could help relieve axial and radicular pain for at least 6 months. Reduced sensitization and removal of calcification and fibrosis were all possible mechanisms.Keywords: Mechanical needling, Sterile water, Ultrasound guided (USG) injection, Facet joint syndrome, Pain

Characterisation of motor cortex organisation in patients with different presentations of persistent low back pain

Persistence of low back pain is thought to be associated with different underlying pain mechanisms, including ongoing nociceptive input and central sensitisation. We hypothesised that primary motor cortex (M1) representations of back muscles (a measure of motor system adaptation) would differ between pain mechanisms, with more consistent observations in individuals presumed to have an ongoing contribution of nociceptive input consistently related to movement/posture. We tested 28 participants with low back pain sub-grouped by the presumed underlying pain mechanisms: nociceptive pain, nociplastic pain and a mixed group with features consistent with both. Transcranial magnetic stimulation was used to study M1 organisation of back muscles. M1 maps of multifidus (deep and superficial) and longissimus erector spinae were recorded with fine-wire electromyography and thoracic erector spinae with surface electromyography. The nociplastic pain group had greater variability in M1 map location (centre of gravity) than other groups (p < .01), which may suggest less consistency, and perhaps relevance, of motor cortex adaptation for that group. The mixed group had greater overlap of M1 representations between deep/superficial muscles than nociceptive pain (deep multifidus/longissimus: p = .001, deep multifidus/thoracic erector spinae: p = .008) and nociplastic pain (deep multifidus/longissimus: p = .02, deep multifidus/thoracic erector spinae: p = .02) groups. This study provides preliminary evidence of differences in M1 organisation in subgroups of low back pain classified by likely underlying pain mechanisms. Despite the sample size, differences in cortical re-organisation between subgroups were detected. Differences in M1 organisation in subgroups of low back pain supports tailoring of treatment based on pain mechanism and motor adaptation.

Prevalence of Self-Reported Work-Related Lower Back Pain and Its Associated Factors in Ethiopia: A Systematic Review and Meta-Analysis

Introduction

Low back pain is the commonest musculoskeletal disorder affecting every socioeconomic group of the world's population. The lifetime risk of developing low back pain is about 60%–80%. The pooled prevalence and associated factors of low back pain have not yet been determined in Ethiopia. Thus, this study was aimed at assessing the overall prevalence of low back pain and its associated factors in Ethiopia.

Methods

A systematic search of PubMed, Scopus, Science Direct, and Google Scholar for observational studies reporting data on the prevalence and associated factors of low back pain was conducted. Relevant data were extracted with a standardized data extraction excel form. Stata 14 was employed for the meta-analysis. Heterogeneity was assessed by Cochran's Q test and I² values of a forest plot. Publication bias was checked using a funnel plot and Egger's test. A random-effects model was used in the analysis.

Result

A total of thirty-two studies were included for the systematic review. Twenty-four and sixteen studies were used to pool the overall low back pain prevalence and associated factors, respectively. The overall pooled annual prevalence of low back pain in Ethiopia was estimated to be 54.05% (95% CI: 48.14–59.96). Age, sex, body mass index, work experience, working hours, lack of safety training, awkward working posture, work shift, prolonged standing, lifting heavy objects, sleeping disturbance, history of back trauma, previous medical history of musculoskeletal disorder, and lack of adequate rest interval at work were significantly associated with low back pain.

Conclusion

The current systematic review and meta-analysis revealed a higher prevalence of lower back pain in Ethiopia. Most of the low back pain epidemiological studies conducted in Ethiopia focused on specific occupational settings, making pooling of data and comparison with other countries challenging. Thus, further general population studies are recommended.

Predictors of pain persistence and disability in high-school students with chronic neck pain at 6-month follow-up

BACKGROUND

Neck pain tends to persist for periods of 1 to 4 years of follow-up in adolescents, and a high percentage of them report disability. However, studies assessing the factors associated with persistent neck pain and disability in this age group are scarce. This study aimed to explore the association between psychosocial factors, sleep, and symptoms of central sensitization at baseline and the persistence of neck pain and disability at 6-month follow-up.

METHODS

A total of 710 adolescents with chronic neck pain were assessed at baseline with an online questionnaire that collected information on sociodemographic data, presence of musculoskeletal pain, pain intensity, physical activity, functional disability, depression, anxiety, stress, quality of sleep, catastrophizing, kinesiophobia, self-efficacy, and symptoms of central sensitization. At 6-month follow-up, adolescents were reassessed for disability and pain intensity and categorized as recovered or reporting persistent neck pain.

RESULTS

Of the 710 participants with neck pain at baseline, 334 were classified as having persistent neck pain and 375 adolescents as being recovered at 6-month follow-up. Multivariable analysis showed that female gender (OR 1.47; p = 0.04) and symptoms of central sensitization (OR 1.02; p = 0.001) at baseline were positively associated with the persistence of neck pain at 6-month follow-up. Similarly, higher levels of disability (β = 0.41; p < 0.001) and symptoms of central sensitization (β = 0.28; p < 0.001) at the baseline were positively associated with disability.

CONCLUSIONS

Symptoms of central sensitization and disability at baseline should be considered in the assessment and design of interventions for adolescents with chronic neck pain as an attempt to minimize its future impact on pain persistence and disability.

Pain Neuroscience Education Delivered by a Student Physical Therapist for a Patient with Persistent Musculoskeletal Pain

BACKGROUND Persistent pain is one of the most common reasons individuals seek healthcare in the United States, costing $635 billion annually. At present, the medical literature outlines many treatments for persistent pain. Pain neuroscience education (PNE) is described in the literature as an educational intervention for patients with persistent pain that can be applied by a physical therapist. There is limited research on the application of PNE by a student physical therapist; however, this case report offers a unique opportunity to examine outcomes for this intervention when applied by a student physical therapist in conjunction with manual therapy and therapeutic exercise. CASE REPORT This case report examined the outcomes of PNE for a 65-year-old patient with a long-standing history of low back, cervical, shoulder, knee, and foot pain. Interventions included 7 sessions of PNE over 4 weeks delivered by a student physical therapist, in combination with manual therapy and exercise prescribed by a licensed physical therapist. Outcomes measured were fear avoidance belief questionnaire, visual analog scale, Tampa scale of kinesiophobia, neurophysiology of pain questionnaire, neck disability index, and Oswestry disability index. CONCLUSIONS Outcomes included clinically significant decreases in subjective pain level, and kinesiophobia; however, there was only a minimal decrease in fear avoidance and no decrease in perceived disability. This case report provides preliminary evidence that positive outcomes can be achieved when PNE is delivered by a student physical therapist combined with manual therapy and therapeutic exercise from an expert clinician for patients with persistent musculoskeletal pain.

Applicability of pain neuroscience education: Where are we now?

BACKGROUND

Explaining pain to patients through pain neuroscience education (PNE) is currently a widespread treatment studied in the musculoskeletal context. Presently, there is sufficient evidence supporting the effectiveness of PNE in patients with chronic musculoskeletal disorders. However, clinicians must pay attention to the actual possibility to transfer research findings in their specific clinical context.

OBJECTIVE

We analysed the applicability of results of studies focused on PNE, which has not been done previously.

METHODS

A detailed discussion on PNE applicability is provided, starting from published randomized controlled trials that investigated the effectiveness of PNE.

RESULTS

This paper markedly points out the awareness of clinicians on the need for an accurate contextualization when choosing PNE as an intervention in clinical practice.

Nociplastic Pain Criteria or Recognition of Central Sensitization? Pain Phenotyping in the Past, Present and Future

Recently, the International Association for the Study of Pain (IASP) released clinical criteria and a grading system for nociplastic pain affecting the musculoskeletal system. These criteria replaced the 2014 clinical criteria for predominant central sensitization (CS) pain and accounted for clinicians' need to identify (early) and correctly classify patients having chronic pain according to the pain phenotype. Still, clinicians and researchers can become confused by the multitude of terms and the variety of clinical criteria available. Therefore, this paper aims at (1) providing an overview of what preceded the IASP criteria for nociplastic pain ('the past'); (2) explaining the new IASP criteria for nociplastic pain in comparison with the 2014 clinical criteria for predominant CS pain ('the present'); and (3) highlighting key areas for future implementation and research work in this area ('the future'). It is explained that the 2021 IASP clinical criteria for nociplastic pain are in line with the 2014 clinical criteria for predominant CS pain but are more robust, comprehensive, better developed and hold more potential. Therefore, the 2021 IASP clinical criteria for nociplastic pain are important steps towards precision pain medicine, yet studies examining the clinimetric and psychometric properties of the criteria are urgently needed.

Agreement and screening accuracy between physical therapists ratings and the Ӧrebro Musculoskeletal Pain Questionnaire in screening for risk of chronic pain during Musculoskeletal evaluation

Introduction: Identifying patients at risk for chronic musculoskeletal pain can inform evaluation and treatment decisions. The ability of physical therapists to assess patients' risk for chronic pain without use of validated tools has been questioned. The Ӧrebro Musculoskeletal Pain Questionnaire (OMPQ) is used to determine risk for chronic pain.Methods: The aim of this pragmatic study was to prospectively quantify the agreement between physical therapists' assessment of patients' risk for chronic symptoms compared to the OMPQ. Patients were asked to complete the OMPQ during the initial visit. Physical therapists, blinded to OMPQ risk classification, carried out their usual patient assessment procedures. The physical therapists rated patients as either high or low risk for chronic pain based on their clinical assessment. Agreement between therapist and OMPQ was determined using Cohen's Kappa (κ) and screening accuracy compared clinician risk to the OMPQ risk classification (reference standard) by way of contingency table analysis.Results: Ninety-six (96) patients' risk classifications and 15 corresponding physical therapists' risk estimates were available for analysis. The OMPQ identified a 47% prevalence for high risk of chronic pain. Agreement (κ and 95% confidence interval) between physical therapist rating and OMPQ was slight, κ = 0.272 (0.033-0.421), p = .026. Therapists' sensitivity and specificity (95% CI) for determining risk classifications were 60.0% (44.3-74.3) and 62.8% (48.1-75.6), respectively. The positive and negative likelihood ratios (95% CI) were 1.61 (1.05-2.47) and 0.64 (0.42-0.97).Discussion: The use of validated self-report questionnaires are recommended to supplement clinician prognosis for patients at risk of chronic musculoskeletal pain.

The development of a novel questionnaire assessing alterations in central pain processing in people with and without chronic pain

Background and aims The purpose of this study was to (a) develop and (b) conduct exploratory factor analysis on a novel self-report instrument for symptoms associated with altered central pain processing. Methods We first developed a 25-item questionnaire based on previous literature identifying symptoms and behaviours that may reflect altered spinal and supraspinal pain processing. We then administered this questionnaire to 183 people with chronic pain (n = 99) and healthy individuals (n = 84). Exploratory factor analysis was conducted to identify the factor structure of the questionnaire. Results Our results support a two-factor solution for the 25-item questionnaire that accounted for 57.2% of the total variance of responses in people with and without chronic pain. Factor one (11 items) included items related to alterations in sensation of pain, while factor two (seven items) included items associated with emotional and fatigue symptoms. Seven items showed weak factor loadings and were eliminated. Reliability was excellent, while both factors showed strong correlations with previously-validated self-report Instruments: (pain catastrophising, mood, vigilance, pain self-efficacy) and conditioned pain modulation, providing evidence for their validity. Conclusions We have developed a questionnaire containing two factors that appear to be related to two different symptom clusters, one of which is specifically related to pain and one of which contains other health-related symptoms related to mood and fatigue. These factors show excellent internal consistency and validity. This questionnaire may be a quick, easy and reliable instrument to assess central pain processing in clinical settings.

The suitability and utility of the pain and movement reasoning model for physiotherapy: A qualitative study

Introduction: The Pain and Movement Reasoning Model is a tool to assist clinical reasoning. It was created for physiotherapists to use in musculoskeletal outpatient clinics but may be appropriate in other clinical contexts. The Model has also been used in physiotherapy education.Objective: To determine physiotherapists' perceptions of the appropriateness (suitability) and benefit (utility) of the Pain and Movement Reasoning Model across clinical contexts in hospital and community practice. Methods Physiotherapists from two health networks in Melbourne, Australia, received training in using the Model and over 4-6 weeks applied it in their clinical interactions. Drawing on a deductive phenomenological approach, transcripts from focus groups and interviews were analysed to determine the suitability and utility of the Model across clinical areas.Results: Twenty-nine physiotherapists from 12 different clinical areas participated. Two themes represented the participants' comments: Suitability for Practice and Utility in Practice. Participants reported the approach to clinical reasoning, promoted by the Model, aligned with existing physiotherapy practice. Enhancements to practice included more comprehensive assessment, selection of broader management techniques and increased confidence with reasoning and explaining the complexity of pain to patients. Participants described using the Model for developing junior staff and training postgraduate students. They also saw potential in adapting the Model for other disciplines and for other multifactorial conditions.Conclusion: Physiotherapists working in a range of clinical contexts considered the Pain and Movement Reasoning Model appropriate and beneficial in clinical practice and in teaching. Further evaluation of the Model in wider settings is warranted.

"How does physical examination findings influence physiotherapists' decision-making when matching treatment to patients with low back pain?"

BACKGROUND

Further clinical data how low-back pain (LBP) symptoms and signs manifests in physiotherapy clinical reasoning and treatment decision-making is needed.

OBJECTIVE

The aim was to explore and describe how symptoms and signs portrayed in three case descriptions of LBP influences physiotherapy treatment decision-making.

DESIGN

This was an exploratory interview study using inductive content analysis.

METHOD

Fifteen semi-structured individual interviews were used to collect data of physiotherapists' treatment decision-making regrading three diverse LBP case descriptions. The participants were men, women, experienced and novice, working in primary healthcare settings in one sparsely populated region and in one larger city in Sweden.

FINDINGS

Two overarching themes were identified influencing decision-making for the treatment of LBP:1) Explicit assessment features distinguish treatment approaches; with categories describing how symptoms and signs were used to target treatment (nature of pain induce reflections on plausible cause; narrative details trigger attention and establishes knowledge-enhancing foci; pain-movement-relationship is essential; diverse emphasis of pain modulation and targeted treatment approaches): and 2) Preconceived notion of treatment, with categories describing personal treatment rationales, unrelated to the presented symptoms and signs (passive treatment avoidance and motor control exercise ambiguity).

CONCLUSION

This study identifies how assessment details lead to decisions on diverse treatment approaches for LBP, but also that treatment decisions can be based on preconceived beliefs unrelated to the clinical presentation. The results underpin the mix of knowledge sources that clinicians need to balance and the necessity of self-awareness of preconceptions for informed and meaningful clinical decision-making.

What does it take to facilitate the integration of clinical practice guidelines for the management of low back pain into practice? Part 1: A synthesis of recommendation

BACKGROUND

Despite the emergence of multiple clinical practice guidelines (CPGs) for the rehabilitation of low back pain (LBP) over the last decade, self-reported levels of disability in this population have not improved. This may be explained by the numerous implementation barriers, such as the complexity of information and sheer volumes of CPGs.

OBJECTIVES

The purpose of this study was to summarize the evidence and recommendations from the most recent and high-quality CPGs on the rehabilitation management of LBP by developing an infographic summarizing the recommendations to facilitate dissemination into clinical practice.

METHODS

We performed a systematic review of high-quality CPGs with an emphasis on rehabilitation approaches. We searched major health-related research databases (e.g., PubMed, CINAHL, and PEDro). We performed quality assessment via the AGREE-II instrument. Contents of the CPGs were synthesized by extracting recommendations, which were then compared to one another to identify consistencies based on an iterative evaluation process.

RESULTS

We identified and assessed 5 recent high-quality CPGs. We synthesized 13 recommendations on the rehabilitation management of LBP (2 for screening procedures, 3 for assessment procedures, and 8 involving treatment approaches) and 2 underlying principles were highlighted. These results were then synthetized and illustrated in a concise infographic that serves as a conceptual roadmap that identifies the specific behavior changes (i.e., adoption of CPGs' recommendations) rehabilitation professionals should adopt in order to integrate an evidenced-based approach for the management of LBP.

CONCLUSIONS

We systematically reviewed the literature for CPGs' recommendations for the physical rehabilitation management of LBP and synthesized the information through an infographic.

Methods to discriminate between mechanism-based categories of pain experienced in the musculoskeletal system: a systematic review

ABSTRACT

Mechanism-based classification of pain has been advocated widely to aid tailoring of interventions for individuals experiencing persistent musculoskeletal pain. Three pain mechanism categories (PMCs) are defined by the International Association for the Study of Pain: nociceptive, neuropathic, and nociplastic pain. Discrimination between them remains challenging. This study aimed to build on a framework developed to converge the diverse literature of PMCs to systematically review methods purported to discriminate between them; synthesise and thematically analyse these methods to identify the convergence and divergence of opinion; and report validation, psychometric properties, and strengths/weaknesses of these methods. The search strategy identified articles discussing methods to discriminate between mechanism-based categories of pain experienced in the musculoskeletal system. Studies that assessed the validity of methods to discriminate between categories were assessed for quality. Extraction and thematic analysis were undertaken on 184 articles. Data synthesis identified 200 methods in 5 themes: clinical examination, quantitative sensory testing, imaging, diagnostic and laboratory testing, and pain-type questionnaires. Few methods have been validated for discrimination between PMCs. There was general convergence but some disagreement regarding findings that discriminate between PMCs. A combination of features and methods, rather than a single method, was generally recommended to discriminate between PMCs. Two major limitations were identified: an overlap of findings of methods between categories due to mixed presentations and many methods considered discrimination between 2 PMCs but not others. The results of this review provide a foundation to refine methods to differentiate mechanisms for musculoskeletal pain.

Hand therapists' perspectives and practices related to musculoskeletal pain: A biopsychosocial lens

BACKGROUND

While the biopsychosocial model is advocated for pain management, biomedical approaches continue to dominate in practice. Understanding musculoskeletal clinicians' perspectives and practices related to pain can inform training needs to optimize care. Little is known regarding the viewpoint of hand therapists who may not have exposure to modern pain models.

OBJECTIVE

To explore hand therapists' perspectives and practices related to musculoskeletal pain using a biopsychosocial lens.

METHODS

This interpretive descriptive qualitative study was embedded in an explanatory sequential mixed methods design. Thirteen hand therapists in the United States were purposefully sampled based on low and high scores on the Revised Neurophysiology of Pain Questionnaire. Each therapist participated in one semi-structured virtual interview. Data were analyzed using open and a priori codes, which were synthesized into themes that aligned with each domain of the biopsychosocial model.

FINDINGS

Participants described "balancing local tissues and the brain," "empowering through education and function," and "looking beyond the individual." Recognition of multidimensional components of pain reinforced participants' awareness that "pain is always real."

DISCUSSION

Hand therapists appreciated pain as a multidimensional phenomenon, with biological, psychological, and social facets. However, a potential bias toward structural pathology warrants additional training to promote high-value musculoskeletal care.

Expert consensus of Chinese Association for the Study of Pain on the non-opioid analgesics for chronic musculoskeletal pain

Chronic musculoskeletal pain (CMP) is a common occurrence in clinical practice and there are a variety of options for the treatment of it. However, the pharmacological therapy is still considered to be a primary treatment. The recent years have witnessed the emergence of opioid crisis, yet there are no relevant guidelines on how to treat CMP with non-opioid analgesics properly. The Chinese Medical Association for the Study of Pain convened a panel meeting to develop clinical practice consensus for the treatment of CMP with non-opioid analgesics. The purpose of this consensus is to present the application of nonsteroidal anti-inflammatory drugs, serotonin norepinephrine reuptake inhibitors, serotonin and norepinephrine reuptake inhibitors, muscle relaxants, ion channel drugs and topical drugs in CMP.

Masterclass: A pragmatic approach to pain sensitivity in people with musculoskeletal disorders and implications for clinical management for musculoskeletal clinicians

INTRODUCTION

Research on musculoskeletal disorders indicates that pain sensitivity can be an important consideration for musculoskeletal clinicians in the holistic view of a patient presentation. However, diversity in research findings in this field can make this a difficult concept for clinicians to navigate. Limited integration of the concept of pain sensitivity into clinical practice for musculoskeletal clinicians has been noted.

PURPOSE

The purpose of this masterclass is to provide a framework for the consideration of pain sensitivity as a contributing factor in the presentation of people with musculoskeletal pain. It provides pragmatic synthesis of the literature related to pain sensitivity through a lens of how this information can inform clinical practice for musculoskeletal clinicians. Guidance is provided in a 'how to' format for integration of this knowledge into the clinical encounter to facilitate personalised care.

IMPLICATIONS

The relationship of pain sensitivity with pain and disability is not clear or linear. The real importance of pain sensitivity in a clinical presentation may be: (1) the potential for pain sensitivity to modify the effect of common treatments utilised by musculoskeletal clinicians, or (2) the effect of pain sensitivity on the prognosis/course of a disorder. Screening tools and subjective features have been highlighted to indicate when physical assessment of pain sensitivity should be prioritised in the physical examination. A pragmatic blueprint for specific assessment related to pain sensitivity has been outlined. A framework for integrating assessment findings into clinical reasoning to formulate management plans for the pain sensitive patient is provided.

Diagnostic accuracy of the clinical indicators to identify central sensitization pain in patients with musculoskeletal pain

Background

The identification of central sensitization (CS) is an important aspect in the management of patients with chronic musculoskeletal pain. Several methods have been developed, including clinical indicators and psychophysical measures. However, whether clinical indicators coincide with the psychophysical test of CS-related sign and symptoms is still unknown. Therefore, the present study aimed to analyze the diagnostic accuracy of the clinical indicators in identifying CS-related sign and symptoms in patients with musculoskeletal pain.

Methods

One-hundred consecutive patients with musculoskeletal pain were included. Clinical indicators (index method) based on a combination of patient self-report pain characteristics and physical examination were used to identify the phenotype of patients with musculoskeletal pain and the predominance of the CS-related sign and symptoms. Conditioned pain modulation (CPM) was assessed by the Cold Pressor Test (reference standard), which is a psychophysical test used to detect impairment of CPM. Measurements of the diagnostic accuracy were performed.

Results

Twenty-seven patients presented predominance of CS-related sign and symptoms in the assessment of the clinical indicators, and 20 had impairment of CPM. Clinical indicators showed high accuracy (75.0%; 95% confidence interval = 65.3 to 83.1), high specificity (80.0%; 95% confidence interval = 69.6 to 88.1), high negative predictive value (87.7%; 95% confidence interval = 81.2 to 92.1), and a relevant positive likelihood ratio (2.8, 95% confidence interval = 1.5 to 5.0) when compared to the Cold Pressor Test.

Conclusion

Clinical indicators demonstrated a valuable tool for detecting the impaired CPM, which is a remarkable feature of the CS-related sign and symptoms. Clinicians are encouraged to use the clinical indicators in the management of patients with musculoskeletal pain.

Female Overrepresentation in Low Back-Related Leg Pain: A Retrospective Study of the Autonomic Response to a Minimally Invasive Procedure

Background

The newly proposed low back pain treatment requires case classification according to the pain mechanism (nociceptive, neuropathic or nociplastic) to determine the most effective therapeutic approach. However, there is a lack of objective tools for distinguishing these pain mechanisms. The aim of the study was to identify which symptoms, signs, and standard diagnostic parameters would allow predicting the nociplastic pain (NP) subtype among low back leg pain (LBLP) patients.

Methods

A retrospective analysis of an LBLP case–control study database was carried out. The presence of NP was assumed if the patient presented with myofascial pain syndrome (MPS) and developed a short-term intensive vasodilatation reaction in the perceived lower leg pain area after provocation by a minimally invasive procedure. Clinical data and standard LBLP diagnostic parameters were analyzed to classify patients as NP (+) vs NP (-). Next, to predict NP probability, logistic regression analysis and a diagnostic classification tree were constructed.

Results

NP was confirmed in 43.75% of LBLP patients. Women represented 95.24% of all NP (+) patients. The diagnostic classification tree indicated that NP was highly probable if the LBLP subject was female and the result of a positive straight leg raise (SLR) test was lower than 45 degrees. If the SLR test result was greater than or equal to 45 degrees, a negative result on the Bragard test would have diagnostic value. This classification tree was approved to a certain extent in the logistic regression model (deviance residuals, min: −1.8519; 1Q: −0.5551; median: −0.1907; 3Q: 0.6565 and max: 2.1058) but should be verified in a larger group of subjects.

Conclusion

Female sex, but not clinical data or standard diagnostic parameters, is indicative of nociplastic pain in LBLP patients. More sophisticated statistical methods, based on directly measurable parameters, should be proposed to distinguish NP involvement in LBLP.