Diagnosing and treating chronic musculoskeletal pain based on the underlying mechanism(s)

Efficacy of aquatic vs land-based therapy for pain management in women with fibromyalgia: a randomised controlled trial

OBJECTIVE

To determine the efficacy of two physiotherapeutic interventions - aquatic therapy (AT) and land-based therapy (LBT) - for reducing pain in women with fibromyalgia.

DESIGN

Single-blind, randomised controlled, equivalence trial.

SETTING

Fibromyalgia, Chronic Fatigue Syndrome and Multiple Chemical Sensitivity Association in A Coruña, Spain.

PARTICIPANTS

Forty women with fibromyalgia were assigned at random in a 1:1 manner to two groups: AT (n = 20) and LBT (n = 20).

INTERVENTIONS

Two therapeutic exercise programmes, with 60-min sessions, were undertaken three times per week for 12 weeks. Sessions were carried out in groups by a trained physiotherapist.

OUTCOME

The primary outcome was pain intensity (visual analogue scale). The secondary outcomes were pressure pain threshold (algometer), quality of life (Revised Fibromyalgia Impact Questionnaire), sleep quality (Pittsburgh Sleep Quality Index), fatigue (Multidimensional Fatigue Inventory) and physical ability (6-Minute Walk Test). Patients were evaluated at baseline, 12 weeks (post-treatment) and 18 weeks (follow-up). The statistical analysis was per-protocol. P < 0.05 was considered to indicate significance. Effect size was calculated.

RESULTS

The mean age was 50 [standard deviation (SD) 9] years, with median body mass index of 27 [interquartile range (IQR) 25-30] kg/m2 and median symptom duration of 11 (IQR 6-15) years. No differences were observed between the groups post-treatment, but differences in favour of AT were found in pain intensity [2.7 (IQR 1.5-4.9) vs 5.5 (IQR 3.3-7.6); p= 0.023; large effect, Cohen's d= 0.8; 95% confidence interval (CI) 0.1-1.5] and sleep quality [12.0 (IQR 7.3-15.3) vs 15.0 (IQR 13.0-17.0); p= 0.030; large effect, Cohen's d= 0.8; 95% CI 0.1-1.5] at follow-up.

CONCLUSIONS

The results suggest that AT is better than LBT for reducing pain intensity and improving sleep quality after 6 weeks of follow-up. AT may be a good treatment option for women with fibromyalgia.

CLINICAL TRIALS REGISTRATION NUMBER

ClinicalTrials.gov NCT02695875 CONTRIBUTION OF THE PAPER.

Neuropathic and Nociplastic Pain Profiles are Common in Adult Chronic Nonbacterial Osteitis (CNO)

Chronic nonbacterial osteitis (CNO) is a rare musculoskeletal disease causing chronic bone pain. It is known that chronic musculoskeletal pain may involve other mechanisms than nociceptive pain only. We investigate the prevalence of neuropathic and nociplastic pain in adult CNO and their association with clinical characteristics and treatment outcomes. Survey study among the Dutch adult CNO cohort (n = 84/195 participated), including PAIN-detect for neuropathic pain, and the Central Sensitization Inventory (CSI), Fibromyalgia Rapid Screening Tool (FiRST), and ACTTION-APS Pain Taxonomy (AAPT) for nociplastic pain. Clinical characteristics and CNO-related bone pain scores were compared between patients with exclusive nociceptive pain and those with nociceptive pain plus neuropathic and/or nociplastic pain (mixed pain). 31% (95% CI 21-41) of patients classified as likely having neuropathic pain according to PAIN-detect. 53% (41-64) of patients displayed central sensitization on CSI, 61% (50-72) screened positive for fibromyalgia on FiRST and 14% (7-23) of patients fulfilled the AAPT criteria, all indicative of nociplastic pain. Mixed pain was associated with longer diagnostic delay (mean difference 2.8 years, 95% CI 0.4-5.2, p = 0.023), lower educational level (72% versus 20%, p < 0.001), and opioid use (37% versus 13%, p = 0.036). Despite comparable disease severity and extent, patients with mixed pain reported significantly higher CNO-related bone pain scores. This study demonstrates the high prevalence of mixed pain in adult CNO, in which neuropathic and nociplastic pain exist alongside nociceptive inflammatory bone pain. Disease burden in CNO may extend beyond inflammatory activity, highlighting the need for a multifaceted management approach.

Influence of Transcutaneous Electrical Nerve Stimulation (TENS) on Pressure Pain Thresholds and Conditioned Pain Modulation in a Randomized Controlled Trial in Women With Fibromyalgia

Transcutaneous electrical nerve stimulation (TENS) effectively reduces pain in fibromyalgia (FM). The purpose of this study was to examine the influence of TENS use on pressure pain thresholds (PPT) and conditioned pain modulation (CPM) in individuals with FM using data from the Fibromyalgia Activity Study with TENS trial (NCT01888640). Individuals with FM were randomly assigned to receive active TENS, placebo TENS, or no TENS for 4 weeks. A total of 238 females satisfied the per-protocol analysis among the active TENS (n = 76), placebo TENS (n = 68), and no TENS (n = 94) groups. Following 4 weeks of group allocation, the active TENS group continued for an additional 4 weeks of active TENS totaling 8 weeks (n = 66), the placebo and no TENS groups transitioned to receive 4 weeks of active TENS (delayed TENS, n = 161). Assessment of resting pain, movement-evoked pain (MEP), PPT, and CPM occurred prior to and following active, placebo, or no TENS. There were no significant changes in PPT or CPM among the active TENS, placebo TENS, or no TENS groups after 4 weeks. Individuals who reported clinically relevant improvements in MEP (≥30% decrease) demonstrated increases in PPT (P < .001), but not CPM, when compared to MEP non-responders. There were no significant correlations among the change in PPT or CPM compared to MEP and resting pain following active TENS use (active TENS + delayed TENS). PPT and CPM may provide insight to underlying mechanisms contributing to pain; however, these measures may not relate to self-reported pain symptoms. PERSPECTIVE: Pressure pain threshold increased in individuals with clinically relevant improvement (≥30%) in MEP, indicating the clinical relevance of PPT for understanding mechanisms contributing to pain. CPM was not a reliable indicator of treatment response in MEP responders.

Testing Biological and Psychological Pathways of Emotion Regulation as a Primary Mechanism of Action in Yoga Interventions for Chronic Low Back Pain: Protocol for a Randomized Controlled Trial

BACKGROUND

Interventions that promote adaptive emotion regulation (ER) skills reduce pain in patients with chronic pain; however, whether the effects of yoga practice on chronic low back pain (CLBP) are due to improvements in ER remains to be examined.

OBJECTIVE

This study will test whether the effects of yoga on CLBP (improved pain severity and interference) are mediated by improved ER, the extent to which effects are related to specific aspects of ER, and the role of pain sensitization as a mediator or moderator of effects. In this study, pain sensitization will be assessed by quantitative sensory testing and gene expression profiles to examine whether pain sensitization moderates yoga's effects on pain or whether yoga and ER abilities reduce pain sensitization, leading to decreased pain severity and interference.

METHODS

For this 2-arm parallel group blinded randomized controlled trial, we will enroll 204 adults with CLBP who will be randomized to receive the yoga (n=102) or a control stretching and strengthening (n=102) intervention, which are delivered via web-based synchronous biweekly 75-minute sessions over 12 weeks. Participants are encouraged to practice postures or exercises for 25 minutes on other days using accessible prerecorded practice videos that are sent to participants digitally. Participants will be assessed at 5 time points: baseline, midintervention (6 weeks), postintervention (12 weeks), and 3- and 6-month follow-ups. Assessments of ER, pain severity and interference, pain sensitivity including somatosensory and gene expression profiles, and physical strength and flexibility will be conducted at each visit. The fidelity of the interventions is assessed using a manualized checklist to evaluate recorded group sessions to ensure consistent instructor delivery.

RESULTS

The primary outcome will be the mean change in pain severity as measured by the Brief Pain Inventory-Short Form at 12 weeks. The primary mechanism of action is ER measured by change in the Difficulties in Emotion Regulation Scale total score. Secondary outcomes include pain sensitivity, physical strength and flexibility, pain interference, and quality of life. A mediation path analysis and series of moderated mediation path analyses will be conducted to test the study hypotheses. As of January 2024, we have enrolled 138 participants. We expect the study to be completed by May 2025.

CONCLUSIONS

The study will provide important data for evaluating whether improvements in ER are responsible for reduced pain perception and pain sensitivity as well as increased quality of life in the context of chronic pain. The study findings have important implications for determining the mechanism of action for yoga and possibly other mind-body interventions as nonpharmacological therapies for pain management. The results of the study will inform the content, delivery, and measures for intervention trials involving yoga as a modality for relieving pain and improving function.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04678297; https://clinicaltrials.gov/study/NCT04678297.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/56016.

Application of a Clinical Approach to Diagnosing Primary Pain: Prevalence and Correlates of Primary Back and Neck Pain in a Community Physiatry Clinic

Chronic back or neck pain (CBNP) can be primary (nociplastic or neuroplastic; without clear peripheral etiology) or secondary (to nociceptive or neuropathic causes). Expanding on available models of nociplastic pain, we developed a clinic-ready approach to diagnose primary/nociplastic pain: first, a standard physical exam and review of imaging to rule out secondary pain; and second, a detailed history of symptom presentation to rule in primary pain. We trained a physician who evaluated 222 patients (73.9% female, age M = 59.6) with CBNP; patients separately completed pain and psychosocial questionnaires. We estimated the prevalence of primary CBNP and explored biomedical, imaging, and psychological correlates of primary CBNP. Although almost all patients (97.7%) had at least 1 spinal anomaly on imaging, the diagnostic approach estimated that 88.3% of patients had primary pain, 5.0% had secondary pain, and 6.8% had mixed pain. Patients with primary pain were more likely than the other 2 groups of patients (combined as "non-primary pain") to report certain functional conditions, central sensitization, and features such as sensitivity to light touch, spreading pain, and pain worsening with stress; however, no difference was detected in depression, anxiety, and pain catastrophizing between those with primary and nonprimary pain. These findings are consistent with prior estimates that 85 to 90% of CBNP is "nonspecific." Further research is needed to validate and perhaps refine this diagnostic approach, which holds the potential for better outcomes if patients are offered treatments targeted to primary pain, such as pain neuroscience education and several emerging psychological therapies. PERSPECTIVE: We developed an approach to diagnose chronic primary pain, which was applied in a physiatry clinic to 222 patients with CBNP. Most patients (88.3%) had primary pain, despite almost universal anomalies on spinal imaging. This diagnostic approach can guide educational and psychological treatments tailored for primary pain.

Rotation-traction manipulation induced intradiskal pressure changes in cervical spine-an in vitro study

Objective: Evaluate the effect of rotation-traction manipulation on intradiskal pressure in human cervical spine specimen with different force and duration parameters, and compare the intradiskal pressure changes between rotation-traction manipulation and traction. Methods: Seven human cervical spine specimens were included in this study. The intradiskal pressure was measured by miniature pressure sensor implanting in the nucleus pulposus. rotation-traction manipulation and cervical spine traction were simulated using the MTS biomechanical machine. Varied thrust forces (50N, 150N, and 250N) and durations (0.05 s, 0.1 s, and 0.15 s) were applied during rotation-traction manipulation with Intradiscal pressure recorded in the neutral position, rotation-anteflexion position, preloading, and thrusting phases. Futuremore, we documented changes in intradiscal pressure during cervical spine traction with different loading forces (50N, 150N, and 250N). And a comparative analysis was performed to discern the impact on intradiscal pressure between manipulation and traction. Results: Manipulation application induced a significant reduction in intradiscal pressure during preloading and thrusting phases for each cervical intervertebral disc (p < 0.05). When adjusting thrust parameters, a discernible decrease in intradiscal pressure was observed with increasing thrust force, and the variations between different thrust forces were statistically significant (p < 0.05). Conversely, changes in duration did not yield a significant impact on intradiscal pressure (p > 0.05). Additionally, after traction with varying loading forces (50N, 150N, 250N), a noteworthy decrease in intradiscal pressure was observed (p < 0.05). And a comparative analysis revealed that rotation-traction manipulation more markedly reduced intradiscal pressure compared to traction alone (p < 0.05). Conclusion: Both rotation-traction manipulation and cervical spine traction can reduce intradiscal pressure, exhibiting a positive correlation with force. Notably, manipulation elicits more pronounced and immediate decompression effect, contributing a potential biomechanical rationale for its therapeutic efficacy.

An overview of systematic reviews examining the quantitative sensory testing-derived hypoalgesic effects of manual therapy for musculoskeletal pain

BACKGROUND

Changes in quantitative sensory testing (QST) after manual therapy can provide insight into pain relief mechanisms. Prior systematic reviews have evaluated manual-therapy-induced QST change. This overview of systematic reviews aims to consolidate this body of literature and critically review evidence on the hypoalgesic effects of manual therapy in clinical populations.

METHODS

A comprehensive search was conducted on PubMed, CINAHL, PsycInfo, and Embase. Peer-reviewed systematic reviews with or without meta-analysis were eligible if the reviews examined the effect of manual therapy compared to non-manual therapy interventions on QST outcomes in clinical populations. Methodological quality was assessed with the AMSTAR 2 tool. Meta-analysis results and qualitative (non-meta-analysis) interpretations were summarized by type of manual therapy. Overlap of studies was examined with the corrected covered area (CCA) index.

RESULTS

Thirty systematic reviews, including 11 meta-analyses, met inclusion. There was a slight overlap in studies (CCA of 1.72% for all reviews and 1.69% for meta-analyses). Methodological quality was predominantly low to critically low. Eight (27%) reviews examined studies with a range of manual therapy types, 13 (43%) reviews focused on joint-biased manual therapy, 7 (23%) reviews focused on muscle-biased manual therapy, and 2 (7%) reviews focused on nerve-biased manual therapy. Twenty-nine (97%) reviews reported on pressure pain threshold (PPT). Meta-analytic results demonstrated conflicting evidence that manual therapy results in greater hypoalgesic effects compared to other interventions or controls.

CONCLUSION

Our overview of QST effects, which has relevance to mechanisms underlying hypoalgesia, shows conflicting evidence from mostly low to critically low systematic reviews.

Video telehealth emotional awareness and expression therapy for older U.S. military veterans with chronic pain: A pilot study

OBJECTIVES

Emotional Awareness and Expression Therapy (EAET) targets trauma and emotional conflict to reduce or eliminate chronic pain, but video telehealth administration is untested. This uncontrolled pilot assessed acceptability, feasibility, and preliminary efficacy of group-based video telehealth EAET (vEAET) for older veterans with chronic musculoskeletal pain.

METHODS

Twenty veterans were screened, and 16 initiated vEAET, delivered as one 60-minute individual session and eight 90-minute group sessions. Veterans completed posttreatment satisfaction ratings and pain severity (primary outcome), pain interference, anxiety, depression, functioning, social connectedness, shame, and anger questionnaires at baseline, posttreatment, and 2-month follow-up.

RESULTS

Satisfaction was high, and veterans attended 7.4 (SD = 0.6) of 8 group sessions; none discontinued treatment. Veterans attained significant, large reductions in pain severity from baseline to posttreatment (p < .001, Hedges' g = -1.54) and follow-up (p < .001, g = -1.20); 14 of 16 achieved clinically significant (≥ 30%) pain reduction, and 3 achieved 90-100% pain reduction. Secondary outcomes demonstrated significant, medium-to-large improvements.

CONCLUSIONS

In this small sample, vEAET produced better attendance, similar benefits, and fewer dropouts than in-person EAET in prior studies. Larger, controlled trials are needed.

CLINICAL IMPLICATIONS

Group vEAET appears feasible and highly effective for older veterans with chronic pain.

Change in Pain-Related Anxiety Mediates the Effects of Psychophysiologic Symptom Relief Therapy (PSRT) on Pain Disability for Chronic Back Pain: Secondary Results from a Randomized Controlled Trial

Purpose

Widely used therapeutic approaches, such as cognitive-behavioral and mindfulness-based therapies, can improve pain and functioning in people with chronic back pain, but the magnitude and duration of their effects are limited. Our team developed a novel 12-week program, psychophysiologic symptom relief therapy (PSRT), to substantially reduce or eliminate pain and disability. This study examined whether PSRT helped more patients achieve large-magnitude (≥30%, ≥50%, ≥75%) reductions in back pain-related disability compared to mindfulness-based stress reduction (MBSR) and usual care (UC), and if the beneficial effects of PSRT were explained by reductions in pain-related anxiety following treatment.

Patients and Methods

Data from a three-armed randomized controlled trial were used (N=35 adults with chronic back pain). Change scores (baseline to 4-, 8-, 13-, and 26-weeks post-enrollment) were computed for back pain disability (RDQ) and pain-related anxiety (PASS-20). Fisher's exact tests and mediation analyses were conducted.

Results

Compared to MBSR and UC, PSRT helped significantly more patients achieve ≥75% reductions in back pain disability at all timepoints and in pain anxiety at all timepoints except 13-weeks. Change in pain anxiety significantly mediated the relationship between treatment group and change in back pain disability from baseline to 26-weeks.

Conclusion

PSRT helped more patients achieve substantial reductions in disability than an established treatment (MBSR) and usual care. Findings indicate reduced pain anxiety may be a mechanism by which PSRT confers long-term benefits on disability. Importantly, this work aims to move the field toward more precise and effective treatment for chronic back pain.

Impact of central sensitization on pain, disability and psychological distress in patients with knee osteoarthritis and chronic low back pain

BACKGROUND

Central sensitization (CS) is becoming increasingly recognized as a significant factor in many chronic pain conditions, including knee osteoarthritis (KOA) and chronic low back pain (CLBP). Yet it presently remains unclear how strong is the involvement of CS in KOA and CLBP and which factors are involved in CS in these two chronic disabling diseases.

METHODS

This is a cross-sectional study in which included a total of 178 patients with KOA and 118 patients with CLBP. Inclusion criteria for eligible participants for the KOA group were a confirmed diagnosis of KOA according to the American College of Rheumatology criteria, and for the CLBP group a chronic low back pain for more than 3 months. Subjects were excluded if they presented with a diagnosed psychiatric disorder or if they lacked the capacity to provide informed consent, understand study questionnaires or perform physical performance tests. In each group, were assessed; CS-related symptoms using the Central Sentization Inventory (CSI); demographic and clinical characteristics such as disease duration, pain intensity on a visual analog scale, self-reported function using the Lequesne index for KOA patients and the Oswestry Disability index for CLBP patients, and physical performance with the 6 minutes' walk test; as well as psychosocial risk factors using the Patient Health Questionnaire for depression (PHQ-9), the Generalized Anxiety Disorder (GAD-7) and the Pain Catastrophizing Scale (PCS).

RESULTS

CSI scores significantly correlated with pain intensity and disability in KOA and CLBP patients, and were highly correlated with self-reported symptoms of depression, anxiety and pain catastrophizing. Depression significantly predicted the CSI score in both groups.

CONCLUSION

These findings provide further evidence for the impact of CS on pain, function and physical performance in KOA and CLBP patients. Psychosocial symptoms such as pain catastrophizing, anxiety and depression should also be considered as they are also associated with CS.

Psychoeducation for Fibromyalgia Syndrome: A Systematic Review of Emotional, Clinical and Functional Related-Outcomes

Fibromyalgia Syndrome (FMS) is a chronic condition of widespread pain accompanied by several symptoms such as stiffness, fatigue, sleep problems, depression, anxiety, and cognitive deficits. To date, there is no specific treatment for FMS. The European League Against Rheumatism, and the majority of the international recommendations for managing FMS, has claimed psychoeducational intervention as the first step in FMS treatment for adequate symptoms management. However, scientific studies in this regard are scarce, diverse, and with contradictory findings. Results integration from analogous studies could provide a clear presentation of the real clinical value of psychoeducation in FMS. Therefore, the current systematic review aims at exploring the effect of psychoeducation on emotional, clinical, and functional symptoms of FMS patients and encourages researchers towards psychoeducation's procedure optimization and systematization. The systematic review was conducted according to the guidelines of the Cochrane Collaboration and PRISMA statements. The selected articles were evaluated using the Cochrane risk of bias (ROB) assessment tool. The selected articles were extracted from PubMed, Scopus, and Web of Science databases. The literature search identified 11 studies eligible for the systematic review. The ROB evaluation revealed that 2 of the 11 studies showed a low quality, the other 2 had a moderate quality, and the remaining 7 studies exhibited a high quality. Results showed that psychoeducation is generally included as an important first therapeutic step in multicomponent treatments for FMS. Moreover, psychoeducation generally seems to be quite beneficial in reducing emotional (i.e., number of days feeling emotionally well, general anxiety, depression levels, etc.) and clinical symptoms (levels of fatigue, morning stiffness, pain intensity, etc.), as well as increasing functional status (i.e., general physical function, morning fatigue, stiffness, etc.). Despite that psychoeducation´s clinical benefits are highlighted, there is scarce amount of research on psychoeducation beyond its usefulness as part of multicomponent treatments.

Relationship between physical activity and central sensitization in chronic low back pain: Insights from machine learning

BACKGROUND AND OBJECTIVES

Chronic low back pain (CLBP) is a leading cause of disability. The management guidelines for the management of CLBP often recommend optimizing physical activity (PA). Among a subsample of patients with CLBP, central sensitization (CS) is present. However, knowledge about the association between PA intensity patterns, CLBP, and CS is limited. The objective PA computed by conventional approaches (e.g. cut-points) may not be sensitive enough to explore this association. This study aimed to investigate PA intensity patterns in patients with CLBP and low or high CS (CLBP-, CLBP+, respectively) by using advanced unsupervised machine learning approach, Hidden semi-Markov model (HSMM).

METHODS

Forty-two patients were included (23 CLBP-, 19 CLBP+). CS-related symptoms (e.g. fatigue, sensitivity to light, psychological features) were assessed by a CS Inventory. Patients wore a standard 3D-accelerometer for one week and PA was recorded. The conventional cut-points approach was used to compute the time accumulation and distribution of PA intensity levels in a day. For the two groups, two HSMMs were developed to measure the temporal organization of and transition between hidden states (PA intensity levels), based on the accelerometer vector magnitude.

RESULTS

Based on the conventional cut-points approach, no significant differences were found between CLBP- and CLBP+ groups (p = 0.87). In contrast, HSMMs revealed significant differences between the two groups. For the 5 identified hidden states (rest, sedentary, light PA, light locomotion, and moderate-vigorous PA), the CLBP- group had a higher transition probability from rest, light PA, and moderate-vigorous PA states to the sedentary state (p < 0.001). In addition, the CBLP- group had a significantly shorter bout duration of the sedentary state (p < 0.001). The CLBP+ group exhibited longer durations of active (p < 0.001) and inactive states (p = 0.037) and had higher transition probabilities between active states (p < 0.001).

CONCLUSIONS

HSMM discloses the temporal organization and transitions of PA intensity levels based on accelerometer data, yielding valuable and detailed clinical information. The results imply that patients with CLBP- and CLBP+ have different PA intensity patterns. CLBP+ patients may adopt the distress-endurance response pattern with a prolonged bout duration of activity engagement.

Pain Widespreadedness, and Not Primary Pain Location, is Associated With Comorbid Symptoms in Children With Chronic Pain

OBJECTIVES

Pediatric chronic pain represents heterogeneous diagnoses; often, primary pain location informs research classifications and treatment. In contrast, recent research has highlighted the role of widespread pain and this perspective has been adopted in assessments in specialty pediatric pain clinics. The lack of direct comparison between these 2 methods of categorizing pediatric chronic pain may hinder the adoption of evidence-based practices across the spectrum of care. Therefore, this study aimed to compare whether primary pain location or pain widespreadedness is more informative for pain-related symptoms in pediatric chronic pain.

METHODS

Youth (n=223) between the ages of 8 to 23 years (M=15.93, SD=2.11, 83% female) completed surveys upon intake at the pediatric chronic pain clinic. Free-text entries of primary pain location were coded into categories: headache, abdominal pain, and musculoskeletal pain. Additional domains assessed included widespread pain, pain interference, kinesiophobia, catastrophizing, anxiety, depression, sleep, and fatigue.

RESULTS

Differences based on primary pain location only emerged for kinesiophobia, F(2150)=8.20, P<0.001, with the highest scores among those with musculoskeletal pain. In contrast, controlling for sex, age, and pain intensity, pain widespreadedness was associated with pain interference, pain catastrophizing, fatigue, anxiety, and depression (P<0.05).

DISCUSSION

Pain widespreadedness was more consistently associated with pain-related outcomes among pediatric chronic pain patients than primary pain location, and body maps may be useful in determining a nociplastic pain mechanism to inform treatment. Improved assessment of pediatric pain mechanisms may help advance more precise treatment delivery.

What is the relationship between physical activity and chronic pain in older adults? A systematic review and meta-analysis protocol

INTRODUCTION

Chronic pain is highly prevalent in older adults and can cause functional limitations, negatively affecting health and quality of life. Physical activity is a non-pharmacological approach used to prevent chronic pain as it promotes the release of endogenous opioids that block pain sensitivity. Therefore, we developed a systematic review protocol to analyse the relationship between physical activity and the occurrence and intensity of chronic pain in older adults.

METHODS AND ANALYSES

The systematic review will search PubMed, Scopus and Embase databases. The inclusion criteria will be observational studies that had primary chronic pain as an outcome, including persistent and intermittent pain. The population will include older adults from the community, living in a long-stay institution, or in outpatient follow-up. There will be no restriction regarding the year of publication and articles published in Portuguese, English and Spanish will be analysed. Effect or impact measures will be quantified, including OR, HR, prevalence ratio, incidence ratio and relative risk with their 95% CIs. If the data allow, a meta-analysis will be performed. The results may help understand the impact of physical activity as a potential protection factor against the occurrence of pain later in life as well as promote strategic prevention plans and public policies that encourage this practice in older adults.

ETHICS AND DISSEMINATION

Ethical approval is not required. The results will be disseminated via submission for publication to a peer-reviewed journal when complete.

PROSPERO REGISTRATION NUMBER

CRD42021282898.

Preoperative Predictors of Complex Regional Pain Syndrome Outcomes in the 6 Months Following Total Knee Arthroplasty

This prospective observational study evaluated preoperative predictors of complex regional pain syndrome (CRPS) outcomes in the 6 months following total knee arthroplasty (TKA). Participants were n = 110 osteoarthritis patients (64.5% female) undergoing unilateral TKA with no prior CRPS history. Domains of negative affect (depression, anxiety, catastrophizing), pain (intensity, widespread pain, temporal summation of pain [TSP]), pain interference, sleep disturbance, and pro-inflammatory status (tumor necrosis factor-alpha [TNF-a]) were assessed preoperatively. CRPS outcomes at 6-week and 6-month follow-up included the continuous CRPS Severity Score (CSS) and dichotomous CRPS diagnoses (2012 IASP criteria). At 6 months, 12.7% of participants met CRPS criteria, exhibiting a "warm CRPS" phenotype. Six-week CSS scores were predicted by greater preoperative depression, anxiety, catastrophizing, TSP, pain intensity, sleep disturbance, and TNF-a (P's < .05). Provisional CRPS diagnosis at 6 weeks was predicted by higher preoperative TSP, sleep disturbance, and TNF-a (P's < .05). CSS scores at 6 months were predicted by more widespread and intense preoperative pain, and higher preoperative TSP, pain interference, and TNF-a (P's < .01). CRPS diagnosis at 6 months was predicted only by more widespread and intense pain preoperatively (P's < .05). Risk for CRPS following TKA appears to involve preoperative central sensitization and inflammatory mechanisms. Preoperative negative affect is unlikely to directly influence long-term CRPS risk. PERSPECTIVE: This article identifies preoperative predictors of CRPS features at 6 months following total knee arthroplasty, including more widespread pain and higher pain intensity, temporal summation of pain, pain interference, and tumor necrosis factor-alpha levels. Findings suggest the importance of central sensitization and inflammatory mechanisms in CRPS risk following tissue trauma.

Systematic Review and Meta-Analysis of High-Frequency rTMS over the Dorsolateral Prefrontal Cortex .on Chronic Pain and Chronic-Pain-Accompanied Depression

The effect of high-frequency (HF) repetitive transcranial magnetic stimulation (rTMS) on the dorsolateral prefrontal cortex (DLPFC) can relieve chronic pain and accompanying depressive symptoms. However, in recent years, some high-quality studies have challenged this view. Therefore, it is necessary to update the data and analyze the effects of HF rTMS on the DLPFC on chronic pain and accompanying depression. We performed a systematic review and meta-analysis to evaluate the effect of HF rTMS on the DLPFC on chronic pain and accompanying depression. We searched PubMed, Medline, Web of Science, and Cochrane through September 2021. The search strings searched were : "pain" AND ("TMS" OR "transcranial magnetic stimulation") AND "prefrontal cortex". The inclusion criteria according to PICOS was as follows: P, patient with chronic pain; I, HF (≥5 Hz) rTMS on the DLPFC; C, included a sham treatment condition; O, pain indicators; S, pre-/poststudies, crossover, or parallel-group. We extracted the pain and accompanying depression evaluation indicators. The short-term analgesic effect of HF rTMS over the left DLPFC is not significant (WMD = 0.34, 95% CI: [-1.60, 2.28]) but has a significant mid-term and long-term analgesic effect on chronic pain (WMD = -0.50, 95% CI: [-0.99, -0.01]; WMD = -1.10, 95% CI: [-2.00, -0.19], respectively). HF rTMS over the DLPFC can effectively alleviate the depressive symptoms of patients with chronic pain (WMD = -0.83, 95% CI: [-3.01, 1.36]). Thus, HF rTMS on the left DLPFC can relieve chronic pain and accompanying depressive symptoms.

Features and methods to discriminate between mechanism-based categories of pain experienced in the musculoskeletal system: a Delphi expert consensus study

ABSTRACT

Classification of musculoskeletal pain based on underlying pain mechanisms (nociceptive, neuropathic, and nociplastic pain) is challenging. In the absence of a gold standard, verification of features that could aid in discrimination between these mechanisms in clinical practice and research depends on expert consensus. This Delphi expert consensus study aimed to: (1) identify features and assessment findings that are unique to a pain mechanism category or shared between no more than 2 categories and (2) develop a ranked list of candidate features that could potentially discriminate between pain mechanisms. A group of international experts were recruited based on their expertise in the field of pain. The Delphi process involved 2 rounds: round 1 assessed expert opinion on features that are unique to a pain mechanism category or shared between 2 (based on a 40% agreement threshold); and round 2 reviewed features that failed to reach consensus, evaluated additional features, and considered wording changes. Forty-nine international experts representing a wide range of disciplines participated. Consensus was reached for 196 of 292 features presented to the panel (clinical examination-134 features, quantitative sensory testing-34, imaging and diagnostic testing-14, and pain-type questionnaires-14). From the 196 features, consensus was reached for 76 features as unique to nociceptive (17), neuropathic (37), or nociplastic (22) pain mechanisms and 120 features as shared between pairs of pain mechanism categories (78 for neuropathic and nociplastic pain). This consensus study generated a list of potential candidate features that are likely to aid in discrimination between types of musculoskeletal pain.

Pain Sensitization and Neuropathic Pain-like Symptoms Associated with Effectiveness of Exercise Therapy in Patients with Hip and Knee Osteoarthritis

Pain sensitization and neuropathic pain-like symptoms are some of the common pain symptoms in patients with lower limbs, including hip and knee, osteoarthritis (HOA/KOA). Exercise therapy has been the first-line treatment; however, the effects differ for each patient. This prospective cohort study investigated the relationship between the effectiveness of exercise therapy and pretreatment characteristics (radiologic severity, pain sensitization, and neuropathic pain-like symptoms) of patients with HOA/KOA. We assessed the pain intensity using a numerical rating scale (NRS) before and after 12 weeks of exercise therapy in patients with HOA/KOA (n = 101). Before treatment, the Kellgren–Lawrence (K-L) grade; minimum joint space width (mJSW); pressure pain threshold (PPT) and temporal summation of pain (TSP) at the affected joint, tibia, and forearm; Central Sensitization Inventory-9; and painDETECT questionnaire (PDQ) were assessed. Cluster analysis was based on the pretreatment NRS and change in NRS with exercise therapy to identify the subgroups of pain reduction. The pretreatment characteristics of each cluster were compared. According to the results of the cluster analyses, patients in cluster 1 had severe pain that did not improve after exercise therapy, patients in cluster 2 had severe pain that improved, and those in cluster 3 had mild pain that improved. The patients in cluster 1 exhibited lower PPT at all measurement sites, higher TSP at the affected joint, and higher PDQ scores than those in other clusters. There was no difference in the K-L grade and mJSW among the clusters. The subgroup with severe pain and pain sensitization or neuropathic pain-like symptoms at pretreatment, even with mild joint deformity, may have difficulty in achieving improvement in pain after 12 weeks of exercise therapy. These findings could be useful for prognosis prediction and for planning exercise therapy and combining with other treatment.

Online ACT intervention for fibromyalgia: An exploratory study of feasibility and preliminary effectiveness with smartphone-delivered experiential sampling assessment

INTRODUCTION

Acceptance and commitment therapy (ACT) is an effective treatment for chronic pain conditions. ACT seeks to produce clinical change by enhancing Psychological Flexibility (PF). This exploratory (feasibility and preliminary effectiveness) study presents a pilot application of an online ACT group intervention for fibromyalgia (FM) with an extensive Experiential Sampling (ES) assessment of outcome and process variables via smartphone.

METHOD

5-weekly ACT online group sessions were applied to 9 female FM patients. Questionnaire-based assessments of several clinical outcomes and PF processes were conducted pre- and post-intervention, and at 6-month follow-up. Extensive (6 weeks pre- and 6 weeks post-intervention) smartphone-delivered ES was implemented to gather process and outcome data in the patients' usual contexts. Clinically significant change was evaluated both at the group level and individually.

RESULTS

This treatment format appears to be feasible and acceptable to participants, with good adoption and completion rates (75 %) and excellent rates of treatment completion and clinical adherence (100 %). Participants showed significant reductions in affective pain, distress and biopsychosocial impact of FM both post-intervention and at 6-month follow-up (as measured with questionnaires), as well as significant improvements in satisfaction with actions and emotional discomfort (as measured through ES). Multilevel regression analyses indicated that PF-related processes assessed through ES had a significant impact on clinical outcomes and predicted the impact of FM at the 6-month follow-up.

CONCLUSIONS

A brief online group ACT intervention for FM was both feasible and acceptable to participants. Also, there was preliminary evidence of effectiveness in enhancing pain-related PF and producing clinical benefits in FM.

Aerobic Physical Exercise as a Non-medical Intervention for Brain Dysfunction: State of the Art and Beyond

Brain disorders, including stroke, Alzheimer's disease, depression, and chronic pain, are difficult to effectively treat. These major brain disorders have high incidence and mortality rates in the general population, and seriously affect not only the patient's quality of life, but also increases the burden of social medical care. Aerobic physical exercise is considered an effective adjuvant therapy for preventing and treating major brain disorders. Although the underlying regulatory mechanisms are still unknown, systemic processes may be involved. Here, this review aimed to reveal that aerobic physical exercise improved depression and several brain functions, including cognitive functions, and provided chronic pain relief. We concluded that aerobic physical exercise helps to maintain the regulatory mechanisms of brain homeostasis through anti-inflammatory mechanisms and enhanced synaptic plasticity and inhibition of hippocampal atrophy and neuronal apoptosis. In addition, we also discussed the cross-system mechanisms of aerobic exercise in regulating imbalances in brain function, such as the “bone-brain axis.” Furthermore, our findings provide a scientific basis for the clinical application of aerobic physical exercise in the fight against brain disorders.

Psychological factors associated with foot and ankle pain: a mixed methods systematic review

BACKGROUND

Foot and ankle pain is common, and generally viewed through a biomedical lens rather than applying a biopsychosocial model. The objectives of this review were to evaluate: (1) the psychosocial characteristics of participants with foot/ankle pain compared to participants without foot/ankle pain; (2) the association between psychosocial factors with pain and function in people with foot/ankle pain; and (3) understand the psychosocial factors associated with the lived experience of foot/ankle pain.

METHODS

A mixed methods systematic review was conducted according to the PRISMA guidelines and guided by the Joanna Briggs Institute methodology for mixed methods systematic reviews. The databases MEDLINE, Embase, CINAHL, SPORTDiscus, PsychInfo, and Scopus were searched. The Mixed Methods Assessment Tool was used to evaluate study quality. A convergent segregated approach was used to synthesise and integrate quantitative and qualitative data.

RESULTS

Eighteen studies were included, consisting of 13 quantitative, 4 qualitative and 1 mixed methods study. The overall quality of the studies was considered high. Integration of the quantitative and qualitative data were not possible due to the disparate nature of the included studies. A narrative synthesis of the quantitative data revealed that negative emotional and cognitive factors were more common in people with foot/ankle pain compared to those without foot/ankle pain. A significant association was also found between emotional distress with foot pain and foot function in some people with plantar heel pain. In addition, kinesiophobia and pain catastrophising were significantly associated with impaired foot function, and pain catastrophising was significantly associated with first step pain in people with plantar heel pain. The qualitative data revealed emotional impacts, physical challenges, and a loss of self which was individual and unpredictable.

CONCLUSIONS

This review provides evidence that negative psychological constructs are greater in participants with foot/ankle pain compared to those without foot/ankle pain, although the cross-sectional nature of the study designs included in this review reduces the certainty of the evidence. These findings indicate that psychological constructs are associated with foot/ankle pain. Further research should evaluate the predictive ability of multidimensional screening tools to identify patients at risk of developing persistent foot/ankle pain.

At the Intersection of Anger, Chronic Pain, and the Brain: A Mini-Review

Chronic pain remains one of the most persistent healthcare challenges in the world. To advance pain treatment, experts have recently introduced research-driven subtypes of chronic pain based on proposed underlying mechanisms. Nociplastic pain (e.g., nonspecific chronic low back or fibromyalgia) is one such subtype which may involve a greater etiologic role for brain plasticity, painful emotions induced by life stress and trauma, and unhealthy emotion regulation. In particular, correlational and behavioral data link anger and the ways anger is regulated with the presence and severity of nociplastic pain. Functional neuroimaging studies also suggest nociplastic pain and healthy anger regulation demonstrate inverse patterns of activity in the medial prefrontal cortex and amygdala; thus, improving anger regulation could normalize activity in these regions. In this Mini-Review, we summarize these findings and propose a unified, biobehavioral model called the Anger, Brain, and Nociplastic Pain (AB-NP) Model, which can be tested in future research and may advance pain care by informing new treatments that address anger, anger regulation, and brain plasticity for nociplastic pain.

Relevance of Religiosity for Coping Strategies and Disability in Patients with Fibromyalgia Syndrome

Coping strategies are essential for the outcome of chronic pain. This study evaluated religiosity in a cohort of patients with fibromyalgia syndrome (FMS), its effect on pain and other symptoms, on coping and FMS-related disability. A total of 102 FMS patients were recruited who filled in questionnaires, a subgroup of 42 patients participated in a face-to-face interview, and data were evaluated by correlation and regression analyses. Few patients were traditionally religious, but the majority believed in a higher existence and described their spirituality as "transcendence conviction". The coping strategy "praying-hoping" and the ASP dimension "religious orientation" (r = 0.5, P < 0.05) showed a significant relationship independent of the grade of religiosity (P < 0.05). A high grade of belief in a higher existence was negatively associated with the choice of ignoring as coping strategy (r = - 0.4, P < 0.05). Mood and affect-related variables had the highest impact on disability (b = 0.5, P < 0.05). In this cohort, the grade of religiosity played a role in the choice of coping strategies, but had no effects on health and mood outcome.

Effect of Pain Reprocessing Therapy vs Placebo and Usual Care for Patients With Chronic Back Pain: A Randomized Clinical Trial

IMPORTANCE

Chronic back pain (CBP) is a leading cause of disability, and treatment is often ineffective. Approximately 85% of cases are primary CBP, for which peripheral etiology cannot be identified, and maintenance factors include fear, avoidance, and beliefs that pain indicates injury.

OBJECTIVE

To test whether a psychological treatment (pain reprocessing therapy [PRT]) aiming to shift patients' beliefs about the causes and threat value of pain provides substantial and durable pain relief from primary CBP and to investigate treatment mechanisms.

DESIGN, SETTING, AND PARTICIPANTS

This randomized clinical trial with longitudinal functional magnetic resonance imaging (fMRI) and 1-year follow-up assessment was conducted in a university research setting from November 2017 to August 2018, with 1-year follow-up completed by November 2019. Clinical and fMRI data were analyzed from January 2019 to August 2020. The study compared PRT with an open-label placebo treatment and with usual care in a community sample.

INTERVENTIONS

Participants randomized to PRT participated in 1 telehealth session with a physician and 8 psychological treatment sessions over 4 weeks. Treatment aimed to help patients reconceptualize their pain as due to nondangerous brain activity rather than peripheral tissue injury, using a combination of cognitive, somatic, and exposure-based techniques. Participants randomized to placebo received an open-label subcutaneous saline injection in the back; participants randomized to usual care continued their routine, ongoing care.

MAIN OUTCOMES AND MEASURES

One-week mean back pain intensity score (0 to 10) at posttreatment, pain beliefs, and fMRI measures of evoked pain and resting connectivity.

RESULTS

At baseline, 151 adults (54% female; mean [SD] age, 41.1 [15.6] years) reported mean (SD) pain of low to moderate severity (mean [SD] pain intensity, 4.10 [1.26] of 10; mean [SD] disability, 23.34 [10.12] of 100) and mean (SD) pain duration of 10.0 (8.9) years. Large group differences in pain were observed at posttreatment, with a mean (SD) pain score of 1.18 (1.24) in the PRT group, 2.84 (1.64) in the placebo group, and 3.13 (1.45) in the usual care group. Hedges g was -1.14 for PRT vs placebo and -1.74 for PRT vs usual care (P < .001). Of 151 total participants, 33 of 50 participants (66%) randomized to PRT were pain-free or nearly pain-free at posttreatment (reporting a pain intensity score of 0 or 1 of 10), compared with 10 of 51 participants (20%) randomized to placebo and 5 of 50 participants (10%) randomized to usual care. Treatment effects were maintained at 1-year follow-up, with a mean (SD) pain score of 1.51 (1.59) in the PRT group, 2.79 (1.78) in the placebo group, and 3.00 (1.77) in the usual care group. Hedges g was -0.70 for PRT vs placebo (P = .001) and -1.05 for PRT vs usual care (P < .001) at 1-year follow-up. Longitudinal fMRI showed (1) reduced responses to evoked back pain in the anterior midcingulate and the anterior prefrontal cortex for PRT vs placebo; (2) reduced responses in the anterior insula for PRT vs usual care; (3) increased resting connectivity from the anterior prefrontal cortex and the anterior insula to the primary somatosensory cortex for PRT vs both control groups; and (4) increased connectivity from the anterior midcingulate to the precuneus for PRT vs usual care.

CONCLUSIONS AND RELEVANCE

Psychological treatment centered on changing patients' beliefs about the causes and threat value of pain may provide substantial and durable pain relief for people with CBP.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03294148.

The Definition, Assessment, and Prevalence of (Human Assumed) Central Sensitisation in Patients with Chronic Low Back Pain: A Systematic Review

Central sensitisation is assumed to be one of the underlying mechanisms for chronic low back pain. Because central sensitisation is not directly assessable in humans, the term 'human assumed central sensitisation' (HACS) is suggested. The objectives were to investigate what definitions for HACS have been used, to evaluate the methods to assess HACS, to assess the validity of those methods, and to estimate the prevalence of HACS. Database search resulted in 34 included studies. Forty different definition references were used to define HACS. This review uncovered twenty quantitative methods to assess HACS, including four questionnaires and sixteen quantitative sensory testing measures. The prevalence of HACS in patients with chronic low back pain was estimated in three studies. The current systematic review highlights that multiple definitions, assessment methods, and prevalence estimates are stated in the literature regarding HACS in patients with chronic low back pain. Most of the assessment methods of HACS are not validated but have been tested for reliability and repeatability. Given the lack of a gold standard to assess HACS, an initial grading system is proposed to standardize clinical and research assessments of HACS in patients with a chronic low back.

Do patients with low back pain and central sensitization have differences in physical fitness?

INTRODUCTION

Low back pain is one of the main musculoskeletal complaints, and may be associated with central sensitization (CS). The physical capacity of patients with low back pain and CS is not very clear.

METHODS

A cross-sectional study, with 92 patients divided into two groups according to their risk of CS. The patient's physical capacity ability was assessed using 6-min walking test (6MWT); timed up and go test (TUG); sit-to-stand test (STS); and trunk flexor, extensor and side-bridge endurance tests. In addition, participants completed questionnaires regarding disability, kinesiophobia, catastrophization and quality of life.

RESULTS

The group with a higher risk of CS had worst performance in the 6MWT (U = 1248; p < 0.001), STS (t(83) = 3.63; p < 0.001) and TUG (t(83) = -4.46; p < 0.001). Similarly, endurance in the right (U = 1453,5; p = 0,002) and left (U = 1467; p = 0,003) side-bridge tests, and the trunk extensor test (U = 1546; p = 0,003) was worse. Disability (U = 1272; p < 0.001), physical capacity kinesiophobia (t(83) = -2.21; p = 0.03) work kinesiophobia (U = 1452; p < 0.001), and pain catastrophization (t(77.57) = -5.03; p < 0.001), were also higher in the group with a higher risk of CS. Quality of life indicators were worse in the higher risk group for all domains of the EQ-5D-3L: Mobility (X²(1) = 12.92; p < 0.001), self-care (X²(1) = 16,3; p = 0,012), usual activities (X²(2) = 14.14; p = 0.001), pain (X²(2) = 27.79; p < 0.001), anxiety and depression (X²(2) = 15.05; p = 0.001).

CONCLUSION

Patients with low back pain and higher risks of CS appear to show lower performance in physical capacity tests, higher rates of disability, kinesiophobia, pain catastrophization, and lower quality of life compared to those with lower risks of CS.

Psychophysiologic symptom relief therapy for chronic back pain: a pilot randomized controlled trial

INTRODUCTION

Chronic back pain is the leading cause of disability in the United States. Based on the hypothesis that nonspecific back pain may be rooted in a psychophysiologic etiology, we propose a new approach to chronic back pain.

OBJECTIVES

A pilot study was conducted to assess whether psychophysiologic symptom relief therapy (PSRT) can reduce disability and back pain bothersomeness for patients with chronic back pain.

METHODS

This was a three-armed, randomized trial for adults with nonspecific chronic back pain that compared PSRT with usual care and an active comparator (mindfulness-based stress reduction [MBSR]). Psychophysiologic symptom relief therapy-randomized participants received a 12-week (36 hours) course based on the psychophysiological model of pain. All groups were administered validated questionnaires at baseline and at 4, 8, 13, and 26 weeks. The primary outcome was the reduction in pain disability measured by the Roland-Morris Disability Questionnaire.

RESULTS

The mean Roland-Morris Disability Questionnaire score for the PSRT group (n = 11) decreased from 9.5 (±4.3 SDs) to 3.3 (±5.1) after 26 weeks which was statistically significant compared with both MBSR (n = 12) (P = 0.04) and usual care (n = 12) (P = 0.03). Pain bothersomeness scores and pain-related anxiety decreased significantly over 26 weeks in PSRT compared with MBSR and usual care (data in manuscript). At 26 weeks, 63.6% of the PSRT arm reported being pain free (0/10 pain) compared with 25.0% and 16.7% in MBSR and usual care arms, respectively. Psychophysiologic symptom relief therapy attendance was 76%, and there was 100% follow-up of all groups.

CONCLUSION

Psychophysiologic symptom relief therapy is a feasible and potentially highly beneficial treatment for patients with nonspecific back pain.

Systematic review and meta-analysis of the prevalence of neuropathic-like pain and/or pain sensitization in people with knee and hip osteoarthritis

OBJECTIVE

To determine the prevalence of neuropathic-like pain (NP) and pain sensitization (PS) defined by self-report questionnaires in knee and hip osteoarthritis, and whether prevalence is potentially explained by disease-severity or affected joint.

DESIGN

MEDLINE, EMBASE, CINAHL were systematically searched (1990-April 2020) for studies describing the prevalence of NP and PS in knee and hip osteoarthritis using self-report questionnaires. Random-effects meta-analysis was performed. Statistical heterogeneity between studies and sub-groups (affected joint and population source as a proxy for disease severity) was assessed (I² statistic and the Chi-squared test).

RESULTS

From 2,706 non-duplicated references, 39 studies were included (2011-2020). Thirty-six studies reported on knee pain and six on hip pain. For knee osteoarthritis, the pooled prevalence of NP was: using PainDETECT, possible NP(score ≥13) 40% (95%CI 32-48%); probable NP(score >18) 20% (95%CI 15-24%); using Self-Report Leeds Assessment of Neuropathic Symptoms and Signs, 32% (95%CI 26-38%); using Douleur Neuropathique (DN4) 41% (95% CI 24-59%). The prevalence of PS using Central Sensitization Inventory (CSI) was 36% (95% CI 12-59%). For hip osteoarthritis, the pooled prevalence of NP was: using PainDETECT, possible NP 29% (95%CI 22-37%%); probable NP 9% (95%CI 6-13%); using DN4 22% (95%CI 12-31%) in one study. The prevalence of possible NP pain was higher at the knee (40%) than the hip (29%) (difference 11% (95% CI 0-22%), P = 0.05).

CONCLUSIONS

Using self-report questionnaire tools, NP was more prevalent in knee than hip osteoarthritis. The prevalence of NP in knee and hip osteoarthritis were similar for each joint regardless of study population source or tool used. Whether defining NP using self-report questionnaires enables more effective targeted therapy in osteoarthritis requires investigation.

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.

Effect of Transversus abdominis muscle training on pressure-pain threshold in patients with chronic low Back pain

Background

Therapeutic training is the most commonly used treatment methods for chronic low back pain (CLBP), and the use of a pressure biofeedback unit for transversus abdominis muscle (TrA) training is one of the core muscle training methods. The study aim of this research is to explore the effects of different intensities (sham training, low-intensity and high-intensity) of TrA muscle training on people with CLBP in pressure-pain threshold (PPT).

Methods

A total of 45 patients with CLBP were recruited, of whom 44 were included in the analysis. Fifteen, 14, and 15 were included in the sham training group, the low-intensity group, and the high-intensity group, respectively. A pressure biofeedback unit was used in performing a one-time TrA training intervention involving 30 times of 180 mmHg TrA contraction training at high intensity for 10 min and 15 times of 100 mmHg TrA contraction training at low intensity for 5 min. The sham training group completed comfort exercises and did not undergo training. The evaluation indicators were as follows: PPT, short-form McGill pain questionnaire, and body surface pain radiation.

Results

High-intensity training could activate more waist core muscles than low-intensity training. Significant changes on PPT (units: kgf) were observed in the following four muscles immediately after high-intensity training: iliopsoas [0.69 (0.13–1.25) 95% CI, p = 0.020]; quadratus lumborum [0.84 (0.23–1.45) 95% CI, p = 0.012]; erector spinae [0.66 (0.18–1.15) 95% CI, p = 0.011]; transversus abdominis [0.70 (0.26–1.14) 95% CI, p = 0.004], and in three muscles after low-intensity training: quadratus lumborum [0.61 (0.17–1.05) 95% CI, p = 0.009]; transversus abdominis [0.14 (from − 0.15 to 0.43) 95% CI, p = 0.022]; piriformis [0.55 (0.13–0.98) 95% CI, p = 0.014]. The change in body surface pain radiation immediately after exercise was [− 10.87 (from − 17.51 to − 4.22) 95% CI, p = 0.003] for high-intensity training and [− 5.21 (from − 9.40 to − 1.03) 95% CI, p = 0.019] for low-intensity training.

Conclusions

TrA training could increase the PPT of the waist core muscles and reduce the radiation range of waist pain. The benefits of high-intensity training are higher than those of low-intensity training.

Trial registration

ChiCTR-TRC-13003701. Registered 18 October 2013.

Code of ethical approval: 2018069.

Editorial for the special issue of the Chinese Association for the Study of Pain

The Ministry of Health of China officially issued a document, adding the first level diagnosis and treatment discipline “Algology” in the list of diagnosis and treatment subjects of medical institutions on July 16, 2007. As the most important pain academic organization in China, the Chinese Association for the Study of Pain has made outstanding contributions in promoting the development of pain discipline and in establishing pain standards and disease diagnosis and treatment guidelines. In this special issue, under the leadership of Yan-Qing Liu, Chairman of the 7^th Committee of the Chinese Association for the Study of Pain, nine consensus and one guideline were included.

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.

Emotional awareness and other emotional processes: implications for the assessment and treatment of chronic pain

Emotional awareness (EA) is a key emotional process that is related to the presence and severity of chronic pain (CP). In this report, we describe primary and secondary emotions, discuss the distinction between emotional states and emotional regulation/processing, and summarize theory and research highlighting the significance of EA for CP. We describe ways to assess EA and diagnose centrally-mediated CP, for which emotional processes appear most relevant. We review several psychological interventions designed to enhance EA as well as several broader emotional processing treatments developed to address trauma and psychosocial conflicts underlying many patients' pain. We conclude by offering our perspective on how future integration of emotional processing into pain care could promote recovery from CP.

Addition of Slowly Repeated Evoked Pain Responses to Clinical Symptoms Enhances Fibromyalgia Diagnostic Accuracy

OBJECTIVE

Fibromyalgia is a chronic pain syndrome characterized by central sensitization. A novel protocol based on slowly repeated evoked pain (SREP) appears to be a useful marker of pain sensitization in fibromyalgia patients. Whether SREP enhances diagnostic accuracy beyond key clinical symptoms that characterize fibromyalgia has not been examined.

METHODS

Fifty fibromyalgia patients, 30 rheumatoid arthritis patients, and 50 healthy individuals were evaluated to assess clinical pain, as well as fatigue, insomnia, pain catastrophizing, and negative mood. The SREP protocol consisted of a series of nine low-intensity painful pressure stimuli of five seconds' duration with 30-second interstimulus intervals. SREP sensitization was indexed by increases in pain intensity ratings across stimuli.

RESULTS

SREP sensitization was observed in fibromyalgia but not in rheumatoid arthritis or healthy individuals. As expected, fibromyalgia patients exhibited a more negative psychosocial profile than did rheumatoid arthritis patients and healthy individuals. SREP was positively associated with clinical pain, fatigue, insomnia, and catastrophizing, but not with negative mood. SREP discriminated fibromyalgia cases from rheumatoid arthritis and healthy individuals even when current clinical pain was included in the analysis. Combining fatigue, insomnia, and SREP led to near perfect diagnostic accuracy (99%) in differentiating fibromyalgia from healthy individuals and 86.3% accuracy in discriminating fibromyalgia from rheumatoid arthritis.

CONCLUSIONS

These results provide further evidence of SREP as a marker of pain sensitization in fibromyalgia and suggest that it captures aspects of fibromyalgia not fully captured by clinical features. Combining SREP with assessment of clinical features could potentially improve fibromyalgia diagnosis.

Correlation Between Central Sensitization and Remote Muscle Performance in Individuals With Chronic Low Back Pain

OBJECTIVE

The purpose of this study was to examine associations between the degree of central sensitization (CS) and remote muscle performance in people with chronic low back pain (CLBP).

METHODS

The 2011 fibromyalgia (FM) criteria and severity scales (2011 FM survey) were used as a surrogate measure of CS to divide the participants into 2 groups: FM-positive CLBP and FM-negative CLBP. Measures related to central sensitization included the 2011 FM survey and pressure pain threshold of the thumbnail. Measures related to muscle performance included neck flexor muscle strength and endurance and plantar flexor muscle strength. Between-groups and correlation analyses were performed.

RESULTS

Sixty people with CLBP were enrolled (30 FM-positive, 30 FM-negative). There was no significant difference between the subgroups in age, sex, or pain duration (P > .05). The FM-positive CLBP group showed poorer neck flexor muscle endurance (P = .01) and plantar flexor muscle strength (P = .002) than the FM-negative CLBP group, whereas neck flexor muscle strength was not different between the groups (P = .175). Scores for FM and values for pressure pain thresholds of the thumbnail were associated with neck flexor muscle strength (respectively, r = -0.320, P = .013, and r = 0.467, P < .001), endurance (r = -0.242, P < .001, and r = 0.335, P = .009), and plantar flexor muscle strength (r = -0.469, P < .001, and r = 0.500, P < .001).

CONCLUSION

We found associations between the degree of CS and remote muscle strength and endurance, suggesting that poor remote muscle performance is possibly a clinical sign of CS in people with CLBP.

Does preoperative neuropathic-like pain and central sensitisation affect the post-operative outcome of knee joint replacement for osteoarthritis? A systematic review and meta analysis

BACKGROUND

Almost a third of those undergoing knee replacement for osteoarthritis have poor outcomes despite technically successful surgery. Preoperative neuropathic-like pain and/or pain sensitisation may increase the risk of pain following joint replacement.

OBJECTIVE

To examine whether preoperative neuropathic-like pain and pain sensitisation predicts pain, function and satisfaction following joint replacement for knee osteoarthritis.

DESIGN

Systematic review with meta-analysis.

METHODS

Medline, EMBASE and CINAHL were systematically searched until March 2020. Studies detecting neuropathic-like pain and/or sensitisation using self-report questionnaires prior to knee replacement for osteoarthritis, and relating this to post-operative outcomes were identified. Data extraction, risk of bias assessment and meta-analysis were performed, where appropriate.

RESULTS

Five manuscripts, including one preprint, examining six cohorts were included: four used painDETECT or modified painDETECT, one the Self-Report Leeds Assessment of Neuropathic Symptoms and Signs, and another the Central Sensitisation Inventory to identify preoperative characteristics. Three studies showed preoperative neuropathic-like pain or sensitisation was associated with more intense post-operative pain. All four studies examining the risk of significant pain after knee replacement suggested it was increased after >3 months. The only study examining patient satisfaction and function found reduced satisfaction, but no difference in function in those with preoperative sensitisation. Meta-analysis found the relative risk of increased pain following knee replacement in those with neuropathic-like pain (painDETECT ≥13) to be 2.05 (95% confidence intervals 1.51, 2.79).

CONCLUSION

These results provide consistent but limited evidence that self-report tools detecting neuropathic-like pain and/or pain sensitisation, predict patients at higher risk of pain following knee replacement.

The Effects of a Pain Psychology and Neuroscience Self-Evaluation Internet Intervention: A Randomized Controlled Trial

OBJECTIVES

Many patients' chronic musculoskeletal pain is strongly influenced by central nervous system processes such as sensitization or amplification. Education about pain neuroscience can change patients' beliefs but has less consistent effects on pain outcomes. Patients may have greater clinical benefits if the educational intervention is personalized, and they evaluate various psychosocial risk factors with respect to their pain. We developed and tested a brief, internet-based Pain Psychology and Neuroscience (PPN) self-evaluation intervention.

MATERIALS AND METHODS

From a patient registry, 104 adults reporting chronic musculoskeletal pain were randomized to the PPN intervention or a matched, active, education control condition. At baseline and 1-month (primary endpoint) and 10-month follow-ups, participants reported pain severity (primary outcome) and multiple secondary outcomes. Primary analyses compared the 2 experimental conditions using analyses of covariances; post hoc exploratory analyses compared the effects of PPN in subgroups of patients who met criteria for fibromyalgia (FM; n=50) or who did not (n=54; primarily spinal pain).

RESULTS

At 1-month follow-up, compared with the control condition, PPN led to significantly lower pain severity (ηp =0.05) and interference (ηp =0.04), greater brain (ηp =0.07) and psychological (ηp =0.07) attributions for pain, and greater readiness for pain self-management (ηp =0.08). Effects on distress, pain catastrophizing, kinesiophobia, and life satisfaction were not significant. Exploratory analyses showed that the PPN intervention was especially beneficial for patients without FM but was of less benefit for those with FM. Most of the effects (except attributions) were lost at 10 months.

DISCUSSION

A brief PPN self-evaluation intervention, presented on-line, can yield short-term improvements in musculoskeletal pain severity and interference, especially for people with spinal/localized pain rather than FM, perhaps because the psychology/neuroscience perspective is more novel for such patients.

Emotional Awareness and Expression Therapy Achieves Greater Pain Reduction than Cognitive Behavioral Therapy in Older Adults with Chronic Musculoskeletal Pain: A Preliminary Randomized Comparison Trial

Objective

Emotional awareness and expression therapy (EAET) emphasizes the importance of the central nervous system and emotional processing in the etiology and treatment of chronic pain. Prior trials suggest EAET can substantially reduce pain; however, only one has compared EAET with an established alternative, demonstrating some small advantages over cognitive behavioral therapy (CBT) for fibromyalgia. The current trial compared EAET with CBT in older, predominately male, ethnically diverse veterans with chronic musculoskeletal pain.

Design

Randomized comparison trial.

Setting

Outpatient clinics at the West Los Angeles VA Medical Center.

Subjects

Fifty-three veterans (mean age = 73.5 years, 92.4% male) with chronic musculoskeletal pain.

Methods

Patients were randomized to EAET or CBT, each delivered as one 90-minute individual session and eight 90-minute group sessions. Pain severity (primary outcome), pain interference, anxiety, and other secondary outcomes were assessed at baseline, post-treatment, and three-month follow-up.

Results

EAET produced significantly lower pain severity than CBT at post-treatment and follow-up; differences were large (partial η2 = 0.129 and 0.157, respectively). At post-treatment, 41.7% of EAET patients had &gt;30% pain reduction, one-third had &gt;50%, and 12.5% had &gt;70%. Only one CBT patient achieved at least 30% pain reduction. Secondary outcomes demonstrated small to medium effect size advantages of EAET over CBT, although only post-treatment anxiety reached statistical significance.

Conclusions

This trial, although preliminary, supports prior research suggesting that EAET may be a treatment of choice for many patients with chronic musculoskeletal pain. Psychotherapy may achieve substantial pain reduction if pain neuroscience principles are emphasized and avoided emotions are processed.

Psychological Therapy for Centralized Pain: An Integrative Assessment and Treatment Model

OBJECTIVE

Chronic pain is a significant health problem that is increasing in prevalence, and advances in treatment are needed.

METHODS

We briefly review the leading evidence-based psychological therapies for chronic pain-cognitive-behavioral and acceptance/mindfulness-based therapies-and examine several limitations and missing perspectives of these approaches. We review six lesser-known interventions that address these limitations, and we describe our integrative model for psychological assessment and treatment of centralized pain. We present a typical patient and describe how we apply this approach, along with challenges to its implementation and possible solutions to these challenges.

RESULTS

Greater pain treatment efficacy may be possible if clinicians: (a) distinguish patients with primarily centralized (i.e., somatoform or nociplastic) pain from those with primarily peripheral (nociceptive, inflammatory, or neuropathic) pain; (b) acknowledge the capacity of the brain not only to modulate pain but also generate as well as attenuate or eliminate centralized pain; (c) consider the powerful role that adverse life experiences and psychological conflicts play in centralized pain; and (d) integrate emotional processing and interpersonal changes into treatment. Our integrative treatment involves delivering a progression of interventions, as needed, to achieve pain reduction: tailored pain neuroscience education, cognitive and mindfulness skills to decrease the pain danger alarm mechanism, behavioral engagement in avoided painful and other feared activities, emotional awareness and expression to reverse emotional avoidance and overcome trauma or psychological conflict, and adaptive communication to decrease interpersonal stress.

CONCLUSIONS

This integrative assessment and treatment model has the potential to substantially reduce and sometimes eliminate centralized pain by changing the cognitive, behavioral, emotional, and interpersonal processes that trigger and maintain centralized pain.

Percutaneous Peripheral Nerve Stimulation for Chronic Low Back Pain: Prospective Case Series With 1 Year of Sustained Relief Following Short-Term Implant

INTRODUCTION

Percutaneous peripheral nerve stimulation (PNS) provides an opportunity to relieve chronic low back pain and reduce opioid analgesic consumption as an alternative to radiofrequency ablation and permanently implanted neurostimulation systems. Traditionally, the use of neurostimulation earlier in the treatment continuum has been limited by its associated risk, invasiveness, and cost.

METHODS

Percutaneous PNS leads (SPRINT MicroLead) were placed bilaterally to target the medial branches of the dorsal rami nerves under image guidance. The percutaneous leads were connected to miniature wearable stimulators (SPRINT PNS System) for the 1-month therapy period, after which the leads were removed. Pain and disability were assessed long-term up to 12 months after lead removal.

RESULTS

Substantial, clinically significant reductions in average pain intensity (≥50% reduction as measured by the Brief Pain Inventory Short Form) were experienced by a majority of subjects (67%) at end of treatment compared to baseline (average 80% reduction among responders; P < 0.05, analysis of variance; n = 9). Twelve months after the end of PNS treatment, a majority of subjects who completed the long-term follow-up visits experienced sustained, clinically significant reductions in pain and/or disability (67%, n = 6; average 63% reduction in pain intensity and 32-point reduction in disability among responders). No serious or unanticipated adverse events were reported.

CONCLUSIONS

This study challenges the long-held notion that a positive trial of PNS should be followed by a permanent implant in responders. Percutaneous PNS may serve as an effective neurostimulation therapy for patients with chronic low back pain and should be considered earlier in the treatment continuum as a motor-sparing means of avoiding opioids, denervation, and permanently implanted neurostimulation systems.

T1ρ-Mapping for Musculoskeletal Pain Diagnosis: Case Series of Variation of Water Bound Glycosaminoglycans Quantification before and after Fascial Manipulation® in Subjects with Elbow Pain

Diagnosis and management of musculoskeletal pain is a major clinical challenge. Following this need, the first aim of our study was to provide an innovative magnetic resonance technique called T_1ρ to quantify possible alterations in elbow pain, a common musculoskeletal pain syndrome that has not a clear etiology. Five patients were recruited presenting chronic elbow pain (>3 months), with an age between 30 and 70 years old. Patients underwent two T_1ρ-mapping evaluations, one before and one after the series of Fascial Manipulation^® (FM) treatments. After the first MRI evaluation, a Disability of the Arm, Shoulder and Hand (DASH) questionnaire was administered to quantify the symptoms and pain intensity. Patients then received three sessions of FM, once a week for 40 min each. A statistically significant difference was found between bound and unbound water concentration before and after FM treatment. Our preliminary data suggest that the application of the manual method seems to decrease the concentration of unbound water inside the deep fascia in the most chronic patients. This could explain the change in viscosity perceived by many practitioners as well as the decrease of symptoms due to the restoration of the normal property of the loose connective tissue. Being able to identify an altered deep fascial area may better guide therapies, contributing to a more nuanced view of the mechanisms of pain.

Exercise and Chronic Pain

In this chapter, we describe the impact and etiology of chronic pain, the associated changes in the nervous system, and the mechanisms by which exercise may be able to affect and reverse these changes. Evidence for efficacy of exercise in different conditions associated with chronic pain is presented, with focus on chronic low back pain, fibromyalgia, osteoarthritis, rheumatoid arthritis, and migraines. While the efficacy of exercise and level of evidence supporting it vary in different diseases, exercise has direct and indirect benefits for most patients suffering from chronic pain. Effective exercise regimens include education and cognitive restructuring to promote behavioral activation and reconceptualization of what pain means, with the goal of gradually reversing the vicious cycle of pain, inertia, sedentary behavior, and worsening disability. Long-term, consistent, individualized exercise-based treatment approaches are most likely to result in improvements in pain and function.

[Hyperuricemia, gout and high cardiovascular risk - how to manage them in clinical practice]

In recent years, the relationship of hyperuricemia and gout with a high risk of cardiovascular disease has been widely discussed. Therefore, it is important to systematically examine patients in order to diagnose comorbidities, among which cardiovascular disease and its complications occupy a leading place and consider mandatory treatment of patients with hyperuricemia and gout with high cardiovascular risk with lowering drugs, which fully reflects the provisions of the latest European recommendations for the management and treatment of patients with gout.

The Physical and the Emotional: Case Report, Mixed-Methods Development, and Discussion

There is a growing recognition that emotional problems are important to physical health outcomes. In response, primary care clinics have introduced self-report checklists to identify patients with emotional disorders such as depression or anxiety. Yet psychodynamic theory posits that certain emotional problems may be unconscious and unspoken, and thus not discernible on self-report checklists, and studies show that checklists do not identify every patient who needs treatment. New clinical tools are needed to identify subtle and complex presentations. We aimed to develop an innovative mixed-methods approach characterizing different types of verbal expression of feelings, drawing on psychodynamic theory and empirical research. We outline the development of the mixed-methods approach, including our theoretical framework and use of semi-structured interview data from Partners in Care (PIC), a randomized controlled trial of quality improvement for depression. We then illustrate the approach with one case: an older female PIC participant who screened positive for depression on all study self-reports. The approach delineates three qualitatively different categories of words-specific feeling words, vague feeling words, and physical words-that were quantified to define a measurable pattern for our participant. Clinicians could be trained to identify these categories of words in the context of a discussion of feelings to better detect and understand subtle emotional problems in patients who have difficulty talking openly about their feelings. Next steps include furthering face and construct validity and test-retest reliability, examining the prevalence of these patterns in a larger sample, and assessing correlates of patterns.

A Prospective Six-Month Study of Chronic Pain Sufferers: A Novel OTC Neuromodulation Therapy

Objective

To assess the durability of treatment over various chronic pain conditions of an emerging, nonprescription electromagnetic neuromodulation device that uses pulsed shortwave therapy.

Methods

A 6-month prospective study, involving 240 chronic pain sufferers, 94% of whom reported using pain pills and 98% reported using pain therapies prior to entering the study. Their average baseline pain was 8.2 VAS points before treatment; they had a pain duration of 6.5 years, and they were positive responders to pulsed shortwave therapy in an initial 7-day trial. Prospective assessments were obtained at intervals of 3, 4, and 6 months following a retrospective 7-day assessment. Longitudinal analyses were conducted to determine pain relief trends after the initial 7-day device use.

Results

Seven days after initial treatment, the average pain was reduced to 2.9, a 65% pain reduction for the study subjects. At the 6-month measurement, the average pain was 3.3, a 60% pain reduction from baseline. Only 17% of the subjects saw their pain level increase although this new level was still lower than baseline pain. Pain relief translated into improved quality of life and reduced medication use for the majority of the subjects. There were no significant adverse side effects reported over the 6 months of use.

Conclusion

Ninety-seven percent of the recruited subjects, all of whom had previously reported clinically significant pain relief using the 7-day PSWT device, sustained this relief for 6 months by using the device on an as-needed basis.

A Subgroup of Chronic Low Back Pain Patients With Central Sensitization

BACKGROUND

Our knowledge of central sensitization (CS) in chronic low back pain (CLBP) is limited. 2011 fibromyalgia criteria and severity scales (2011 FM survey) have been used to determine FM positive as a surrogate of CS. The major features of CS including widespread hyperalgesia and dysfunction of the descending inhibitory pathways can be identified by pressure pain threshold (PPT) and conditioned pain modulation (CPM) tests. The purpose of the study was to examine neurophysiological characteristics and psychosocial symptoms in a subgroup of FM-positive CLBP compared with FM-negative CLBP patients.

METHODS

A total of 46 participants with CLBP and 22 pain-free controls completed outcome measures of the 2011 FM survey, PPT and CPM tests, and psychosocial questionnaires. Differences between FM-positive and FM-negative CLBP participants on these measures and correlations were analyzed.

RESULTS

The 2011 FM survey identified 22 (48%) participants with CLBP as FM positive. FM-positive CLBP participants showed lower PPT values of the thumbnail (P=0.011) and lower back (P=0.003), lower CPM values of the thumbnail (P=0.002), and more severe pain catastrophizing, anxiety, and depression symptoms (P<0.05) than FM-negative CLBP participants. The 2011 FM scores were significantly correlated with the PPT and CPM values of the thumbnail and with psychosocial symptoms (P<0.001).

DISCUSSION

Our findings suggest a subgroup of CLBP patients exhibiting with signs and symptoms of CS. Associations between subjective and objective CS measures indicate that the 2011 FM survey can be utilized to identify the presence of CS in CLBP in clinical practice.