Pathophysiology of musculoskeletal pain: a narrative review

Automated Pain Spots Recognition Algorithm Provided by a Web Service-Based Platform: Instrument Validation Study

Background

Understanding the causes and mechanisms underlying musculoskeletal pain is crucial for developing effective treatments and improving patient outcomes. Self-report measures, such as the Pain Drawing Scale, involve individuals rating their level of pain on a scale. In this technique, individuals color the area where they experience pain, and the resulting picture is rated based on the depicted pain intensity. Analyzing pain drawings (PDs) typically involves measuring the size of the pain region. There are several studies focusing on assessing the clinical use of PDs, and now, with the introduction of digital PDs, the usability and reliability of these platforms need validation. Comparative studies between traditional and digital PDs have shown good agreement and reliability. The evolution of PD acquisition over the last 2 decades mirrors the commercialization of digital technologies. However, the pen-on-paper approach seems to be more accepted by patients, but there is currently no standardized method for scanning PDs.

Objective

The objective of this study was to evaluate the accuracy of PD analysis performed by a web platform using various digital scanners. The primary goal was to demonstrate that simple and affordable mobile devices can be used to acquire PDs without losing important information.

Methods

Two sets of PDs were generated: one with the addition of 216 colored circles and another composed of various red shapes distributed randomly on a frontal view body chart of an adult male. These drawings were then printed in color on A4 sheets, including QR codes at the corners in order to allow automatic alignment, and subsequently scanned using different devices and apps. The scanners used were flatbed scanners of different sizes and prices (professional, portable flatbed, and home printer or scanner), smartphones with varying price ranges, and 6 virtual scanner apps. The acquisitions were made under normal light conditions by the same operator.

Results

High-saturation colors, such as red, cyan, magenta, and yellow, were accurately identified by all devices. The percentage error for small, medium, and large pain spots was consistently below 20% for all devices, with smaller values associated with larger areas. In addition, a significant negative correlation was observed between the percentage of error and spot size (R=-0.237; P=.04). The proposed platform proved to be robust and reliable for acquiring paper PDs via a wide range of scanning devices.

Conclusions

This study demonstrates that a web platform can accurately analyze PDs acquired through various digital scanners. The findings support the use of simple and cost-effective mobile devices for PD acquisition without compromising the quality of data. Standardizing the scanning process using the proposed platform can contribute to more efficient and consistent PD analysis in clinical and research settings.

Systemic administration of Resolvin D1 reduces cancer-induced bone pain in mice: Lack of sex dependency in pain development and analgesia

AIMS

Bone cancer produces severe pain that is treated with opioids, but serious side effects limit opioid utilization. There is therefore a need to develop effective and safe non-opioid alternatives. The lipid mediator, Resolvin D1 (RvD1), could be a prospective candidate for cancer pain treatment. To assess RvD1 and other potential candidates, appropriate animal models that recapitulate clinical features must be used. Although several preclinical models of cancer pain have been developed, the influence of sex on the development of cancer pain and the effectiveness of RvD1 have not been studied.

RESULTS

Using a mouse model of fibrosarcoma growth in and around the calcaneus bone, we demonstrated that the mechanical hyperalgesia in the tumor-bearing hind paw develops independently of sex, except that it developed a little sooner in female mice. A single intravenous injection of RvD1 (0.001-10 μg/kg) decreased hyperalgesia in both sexes with similar potency (ED50 = 0.0015 μg/kg) and efficacy. Repeated daily administration of 10 μg/kg RvD1 prolonged the analgesic effect and completely abolished hyperalgesia. This was also independent of sex.

CONCLUSION

In this preclinical mouse model of bone cancer pain, the development of pain and the analgesic effectiveness of RvD1 are not influenced by sex.

Transforming Veteran Rehabilitation Care: Learnings from a Remote Digital Approach for Musculoskeletal Pain

While musculoskeletal pain (MSP) stands as the most prevalent health condition among Veterans, timely and high-quality care is often hindered due to access barriers. Team Red, White & Blue (Team RWB), a nonprofit organization dedicated to promoting a healthier lifestyle among Veterans, aimed to assess innovative approaches to veteran care. This is a single-arm pilot study investigating the feasibility, clinical outcomes, engagement, and satisfaction of a remote multimodal digital care program among Veterans with MSP. The impact of deployment experience on outcomes was explored as a secondary aim. From 75 eligible Veterans, 61 started the program, reporting baseline pain frequently comorbid with mental distress. Program acceptance was suggested by the high completion rate (82%) and engagement levels, alongside high satisfaction (9.5/10, SD 1.0). Significant improvements were reported in all clinical outcomes: pain (1.98 points, 95%CI 0.13; 3.84, p = 0.036); mental distress, with those reporting at least moderate baseline depression ending the program with mild symptoms (8.50 points, 95%CI: 6.49; 10.51, p = 0.012); daily activity impairment (13.33 points, 95%CI 1.31; 25.34, p = 0.030). Deployed Veterans recovered similarly to their counterparts. Overall, the above results underscore the potential of a remote digital intervention to expand Veterans' access to timely MSP care.

Clinical Characterization of New-Onset Chronic Musculoskeletal Pain in Long COVID: A Cross-Sectional Study

Purpose

New-onset chronic musculoskeletal (MSK) pain is one of the common persistent symptoms in Long COVID (LC). This study investigated its clinical characteristics, underlying mechanisms, and impact on function, psychological health, and quality of life.

Patients and Methods

Thirty adults (19 female, 11 male) with LC and new-onset chronic MSK pain underwent clinical examination, Quantitative Sensory Testing (QST), and blood tests for inflammatory markers and completed the following outcome measures: Timed Up and Go test (TUG), handgrip strength test, COVID-19 Yorkshire Rehabilitation Scale (C19-YRS), Brief Pain Inventory (BPI), Pain Self-Efficacy Questionnaire (PSEQ), Pain Catastrophizing Scale (PCS), International Physical Activity Questionnaire-short form (IPAQ-sf), Generalized Anxiety Disorder (GAD-7), Patient Health Questionnaire (PHQ-9), and EuroQol Five Dimensions health-related quality of life (EQ-5D-5L).

Results

New-onset chronic MSK pain was widespread and continuous in nature, and worse in the joints. When compared to normative values reported in the literature: a) QST revealed mechanical hyperalgesia, heightened temporal summation of pain, and hypoesthesia to vibration stimuli, which is strongly suggestive of central sensitization; b) Plasma cytokine assays indicated distinct pro-inflammatory profiles; c) TUG time indicated reduced balance and mobility; d) handgrip strength revealed general weakness; e) physical activity was lower; and f) there were moderate levels of depression and anxiety with lower self-efficacy scores and lower levels of pain catastrophizing. LC symptoms were of moderate severity (44.8/100), moderate functional disability (22.8/50) and severely compromised overall health (2.6/10) when compared to pre-COVID scores.

Conclusion

New-onset chronic MSK pain in LC tends to be widespread, constant, and associated with weakness, reduced function, depression, anxiety, and reduced quality of life. There is associated central sensitization and proinflammatory state in the condition. Further research is essential to explore the longitudinal progression and natural evolution of the new-onset chronic MSK pain in LC.

Microbial Symphony: Exploring the Role of the Gut in Osteoarthritis-Related Pain. A Narrative Review

One of the most common musculoskeletal disorders, osteoarthritis (OA), causes worldwide disability, morbidity, and poor quality of life by degenerating articular cartilage, modifying subchondral bone, and inflaming synovial membranes. OA pathogenesis pathways must be understood to generate new preventative and disease-modifying therapies. In recent years, it has been acknowledged that gut microbiota (GM) can significantly contribute to the development of OA. Dysbiosis of GM can disrupt the "symphony" between the host and the GM, leading to a host immunological response that activates the "gut-joint" axis, ultimately worsening OA. This narrative review summarizes research supporting the "gut-joint axis" hypothesis, focusing on the interactions between GM and the immune system in its two main components, innate and adaptive immunity. Furthermore, the pathophysiological sequence of events that link GM imbalance to OA and OA-related pain is broken down and further investigated. We also suggest that diet and prebiotics, probiotics, nutraceuticals, exercise, and fecal microbiota transplantation could improve OA management and represent a new potential therapeutic tool in the light of the scarce panorama of disease-modifying osteoarthritis drugs (DMOADs). Future research is needed to elucidate these complex interactions, prioritizing how a particular change in GM, i.e., a rise or a drop of a specific bacterial strain, correlates with a certain OA subset to pinpoint the associated signaling pathway that leads to OA.

Markers of Tissue Deterioration and Pain on Earth and in Space

Purpose

Pain is an understudied physiological effect of spaceflight. Changes in inflammatory and tissue degradation markers are often associated with painful conditions. Our aim was to evaluate the changes in markers associated with tissue deterioration after a short-term spaceflight.

Patients and Methods

Plasma levels of markers for systemic inflammation and tissue degeneration markers were assessed in two astronauts before and within 24 h after the 17-day Axiom Space AX-1 mission.

Results

After the spaceflight, C-reactive protein (CRP) was reduced in both astronauts, while INFγ, GM-CSF, TNFα, BDNF, and all measured interleukins were consistently increased. Chemokines demonstrated variable changes, with consistent positive changes in CCL3, 4, 8, 22 and CXCL8, 9, 10, and consistent negative change in CCL8. Markers associated with tissue degradation and bone turnover demonstrated consistent increases in MMP1, MMP13, NTX and OPG, and consistent decreases in MMP3 and MMP9.

Conclusion

Spaceflight induced changes in the markers of systemic inflammation, tissue deterioration, and bone resorption in two astronauts after a short, 17-day, which were often consistent with those observed in painful conditions on Earth. However, some differences, such as a consistent decrease in CRP, were noted. All records for the effect of space travel on human health are critical for improving our understanding of the effect of this unique environment on humans.

The biopsychosocial factors associated with development of chronic musculoskeletal pain. An umbrella review and meta-analysis of observational systematic reviews

AIM

The aim of this umbrella review was to establish which biopsychosocial factors are associated with development of chronic musculoskeletal pain.

METHODS

Ovid Medline, Embase, Web of Science Core Collection, Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects, PsycINFO, CINAHL, PEDro, PROSPERO, Google Scholar and grey literature were searched from database inception to 4th April 2023. Systematic reviews of observational prospective longitudinal studies, including populations with <3 months (not chronic) musculoskeletal pain, investigating biopsychosocial factors that contribute to development of chronic (>3 months) musculoskeletal pain. Two reviewers searched the literature, assessed risk of bias (Assessing the Methodological Quality of Systematic Reviews-2), and evaluated quality (Grading of Recommendations, Assessment, Development and Evaluation) to provide an overall statement on the certainty of evidence for each biopsychosocial factor. Data analysis was performed through random effects meta-analysis (including meta-analysis of meta-analyses where possible) and descriptive synthesis.

RESULTS

13 systematic reviews were included comprising 185 original research studies (n = 489,644 participants). Thirty-four biopsychosocial factors are associated with development of chronic musculoskeletal pain. Meta-analyses of odds and/or likelihood ratios were possible for 25 biopsychosocial factors. There is moderate certainty evidence that smoking (OR 1.24 [95%CI, 1.14-1.34), fear avoidance (LR+ 2.11 [95%CI, 1.59-2.8]; LR- 0.5 [95%CI, 0.35-0.71]) poorer support networks (OR 1.21 [95%CI, 1.14-1.29]), lower socioeconomic status (OR 2.0 [95%CI, 1.64-2.42]), and high levels of pain (OR 5.61 [95%CI, 3.74-8.43]) are associated with development of chronic musculoskeletal pain (all P<0.001). Remaining factors are of low or very low certainty evidence.

CONCLUSIONS AND RELEVANCE

There is moderate certainty evidence that smoking, fear avoidance, poorer support networks, lower socioeconomic status, and high levels of pain are associated with development of chronic musculoskeletal pain. High risk of bias was evident in most included reviews; this highlights the need for higher quality systematic reviews.

Musculoskeletal pain among medical residents: role of workplace safety climate and sexual harassment

BACKGROUND

Workplace factors are important predictors of occurrence of musculoskeletal pain among different occupational populations. In healthcare, a psychologically unsafe work environment can negatively affect the emotional, physical and psychological well-being of physicians. This study aimed to examine the relationship between workplace violence, sexual harassment and musculoskeletal pain among Egyptian physicians in their years of residency.

METHODS

We distributed an online self-administered questionnaire to 101 residents working in various healthcare sectors in Egypt. It included sections on demographic data, working conditions, widespread pain index (WPI), pain interference short-form, workplace violence and harassment questionnaire, psychosocial safety climate questionnaire (PSC) and sexual harassment climate questionnaire.

RESULTS

All residents had at least one painful site on the WPI (range 1-11). The mean WPI was 3.5 ± 2.4, and 39.6% satisfied the criteria of having widespread pain by having at least 4 pain sites. Widespread pain index showed a weak statistically significant negative correlation with workplace PSC score (rho = - 0.272, p = 0.006), and a statistically significant weak positive correlation with the calculated total abuse index (rho = 0.305, p = 0.002). Workplace violence and abuse, as measured by a calculated abuse index was the only significant predictors of widespread pain among residents.

CONCLUSION

WPV was found to be a predictor of musculoskeletal pain among medical residents. Healthcare organizations need to address WPV by employing preventive strategies to minimize its hazardous effects and ensure a safe working environment for physicians.

Computer-modified paramedian approach technique reduces failures and alleviates pain in lumbar puncture: a prospective comparative study

Background

The conventional midline approach for lumbar puncture (MAT-LP) has a relatively low success rate of 70%. The paramedian approach can increase the effective puncture area and success rate but lacks standardized guidelines. This study evaluated a computer-modified paramedian approach technique (CMPAT) to optimize lumbar puncture using computational techniques.

Methods

In this prospective study, 120 patients underwent CMPAT-LP (n = 60) or MAT-LP (n = 60). Puncture failure was defined after 6 attempts. Failure rate, number of attempts, pain score, and complications were compared. Subgroup analysis was conducted for age (≥ 50 years).

Results

No significant demographic differences existed between groups. Failure rates were 3.3% for CMPAT vs. 13.3% for MAT. Puncture attempts averaged 2.0 vs. 3.5 and pain scores were 2.7 vs. 4.1 for CMPAT and MAT, respectively. All outcomes were significantly improved with CMPAT, especially in elderly patients. No significant difference in complications was observed.

Conclusion

Compared to MAT, CMPAT-LP demonstrated lower failure rates, fewer puncture attempts, and less pain, without compromising safety. CMPAT may be superior and should be more widely implemented in clinical practice.

Yoga for musculoskeletal pain, discomfort, perceived stress, and quality of sleep in industry workers: a randomized controlled trial

BACKGROUND AND OBJECTIVES

Work-related musculoskeletal pain and discomfort are due to repetitive, unnatural, continuous movements and postures. Yoga therapy is beneficial for pain and disability in occupational settings. The current study aims to investigate the effect of yoga on musculoskeletal pain, stress, and sleep quality among industry workers.

METHODOLOGY

The study was conducted as a parallel randomized controlled open-label trial. An allocation ratio of 1:1 was followed for randomization. A health survey was used to recruit 90 male workers in machinery manufacturing industries from Bengaluru. A specially designed yoga module was administered five days a week for eight weeks to yoga group. The waitlisted control group received lifestyle suggestions. Cornell Musculoskeletal Discomfort Questionnaire (CMDQ), Perceived Stress Scale (PSS), and Pittsburgh Sleep Quality Index (PSQI) were administered at baseline, at the fourth week and eighth weeks. Repeated Measures Analysis of Variance (RM-ANOVA) was conducted to elicit the group*time interactions.

RESULTS

Ninety participants (Yoga = 45, Control = 45) with age 40.57 ± 6.85 were randomized. Significant interactions were found in CMDQ, VAS, PSS and PSQI scores. Further, between group comparison demonstrate significant difference between the groups at the end of 8 weeks for CMDQ, VAS and PSS scores.

CONCLUSIONS

Yoga can be used to reduce musculoskeletal pain, discomfort, perceived stress and improve sleep quality among industry workers.

TRIAL REGISTRATION NUMBER

CTRI/2022/03/040894.

Spanish version of the pain beliefs questionnaire: Translation, cross-cultural adaptation, validation, and psychometric properties in a working population

BACKGROUND

Chronic musculoskeletal pain is a major health problem and a common cause of disability in the workplace. Beliefs related to musculoskeletal pain may influence its onset and perpetuation. Consequently, tools designed to identify potentially harmful beliefs are needed. However, the Pain Beliefs Questionnaire (PBQ) is not available for individuals speaking European-Spanish.

OBJECTIVES

To translate and culturally adapt the original English version of the PBQ into European-Spanish and evaluate its psychometric properties among Spanish workers with and without chronic musculoskeletal pain.

DESIGN

Study on measurement properties.

METHODS

A translation and cultural adaptation process was based on a forward-backward translation process. One hundred fifty-one active workers were included. Participants completed the PBQ (composed of the organic and psychological subscales), the Pain Catastrophizing Scale (PCS), and the Hospital Anxiety and Depression Scale (HADS). Finally, thirty participants completed the PBQ again two weeks later for test-retest reliability.

RESULTS

The PBQ showed adequate internal consistency (Cronbach's alpha: 0.72-0.73), good item response stability (weighted Kappa: 0.65-0.90), and reliability (Intraclass Correlation Coefficient: 0.72-0.80). A positive correlation was found between the PCS and the organic subscale (r = 0.403). However, no significant correlations were found between the HADS and the PBQ subscales. Workers with chronic musculoskeletal pain showed greater scores in the organic subscale and lower scores in the psychological subscale than workers without pain.

CONCLUSION

The Spanish version of the PBQ was linguistically accurate and acceptable for use by workers with and without musculoskeletal pain.

Regulatory T-cells and IL-5 mediate pain outcomes in a preclinical model of chronic muscle pain

Fibromyalgia (FM) is a chronic musculoskeletal pain disorder primarily diagnosed in women. Historically, clinical literature focusing on cytokines and immune cells has been inconsistent. However, recent key studies show several layers of immune system dysfunction in FM. Preclinically, studies of the immune system have focused on monocytes with little focus on other immune cells. Importantly, T-cells are implicated in the development and resolution of chronic pain states, particularly in females. Our previous work showed that monocytes from women with FM produced more interleukin 5 (IL-5) and systemic treatment of IL-5 reversed mechanical hypersensitivity in a preclinical model of FM. Typically, IL-5 is produced by T_H2-cells, so in this study we assessed T-cell populations and cytokine production in female mice using the acid-induced chronic muscle pain model of FM before and after treatment with IL-5. Two unilateral injections of pH4.0 saline, five days apart, into the gastrocnemius muscle induce long-lasting widespread pain. We found that peripheral (blood) regulatory T_helper-cells (CD4⁺ FOXP3+) are downregulated in pH4.0-injected mice, with no differences in tissue (lymph nodes) or CD8⁺ T-cell populations. We tested the analgesic properties of IL-5 using a battery of spontaneous and evoked pain measures. Interestingly, IL-5 treatment induced place preference in mice previously injected with pH4.0 saline. Mice treated with IL-5 show limited changes in T-cell populations compared to controls, with a rescue in regulatory T-cells which positively correlates with improved mechanical hypersensitivity. The experiments in this study provide novel evidence that downregulation of regulatory T-cells play a role in chronic muscle pain pathology in the acidic saline model of FM and that IL-5 signaling is a promising target for future development of therapeutics.

Palmitoyl-glucosamine co-micronized with curcumin for maintenance of meloxicam-induced pain relief in dogs with osteoarthritis pain

BACKGROUND

Osteoarthritis (OA) pain is the number one cause of chronic pain in dogs. Multimodal treatment, including combining safe and effective nutritional interventions with non-steroidal anti-inflammatory drugs (NSAIDs), is currently considered one of the most appropriate choices for managing OA pain. Palmitoyl-glucosamine is a feed material belonging to the ALIAmide family, whose parent molecule is the prohomeostatic lipid amide N-palmitoyl-ethanolamine. Curcumin is a promising plant antioxidant. The present study aimed at investigating whether 18-week dietary integration with palmitoyl-glucosamine co-micronized with curcumin was able to maintain pain relief in dogs with OA-associated chronic pain receiving meloxicam (1.5 mg/ml oral suspension) on a tapering regimen (progressive 25% decrease of the original 0.1 mg/kg/day dose, on a biweekly basis) during the first 8 weeks of treatment. Pain was assessed both by the owners and veterinary surgeons, with the first using both subjective evaluation and validated metrology instruments-i.e., Helsinki Chronic Pain Index (HCPI) and Canine Brief Pain Inventory (CBPI)-while the second rating the severity of lameness and pain on palpation on two previously used 5-point scales.

RESULTS

A total of fifty-eight dogs with OA chronic pain entered the uncontrolled study. Pain on HCPI was considered severe at baseline (range 18-39). Based on owner's assessment, 90% of dogs who responded to meloxicam at the full-dose regimen could reduce meloxicam up to 25% of the original dose without experiencing pain worsening. Moreover, 75% of dogs was assessed as having no pain increase ten weeks after meloxicam withdrawal. A statistically significant decrease of pain severity as scored by HCPI (P < 0.0001) was observed two and ten weeks after meloxicam withdrawal compared to study entry (17.0 ± 1.05 and 15.1 ± 1.02, respectively, vs 29.0 ± 0.74; mean ± SEM). After meloxicam withdrawal, no statistically significant change in the CBPI scores was recorded. Pain on palpation and lameness significantly changed to less severe distributions along the study period (P < 0.0001).

CONCLUSION

The findings appear to suggest that dietary integration with palmitoyl-glucosamine co-micronized with curcumin was able to maintain meloxicam-induced pain relief in dogs with severe OA chronic pain.

An International Multidisciplinary Delphi-Based Consensus on Heat Therapy in Musculoskeletal Pain

INTRODUCTION

Musculoskeletal pain (MP) is prevalent in our society, having a strong negative impact on physical and psychosocial quality of life. Heat therapy (HT) has been frequently described as a treatment strategy for musculoskeletal pain, but scientific evidence is still poor. The aim of the present Delphi method study is to gather a consensus among European experts on the role of HT in MP.

METHODS

To address this topic, a list of 54 statements was developed, concerning mechanism of action of heat on muscle, types of MP eligible for heat treatment, efficacy of HT, time and modalities of treatment, maximizing compliance to HT, safety (based on heat wraps), wrong beliefs and common errors in the prescription of HT and the role of HT in preventing muscular damage in athletes. The survey was distributed to 116 European experts, using a 5-point Likert scale to express agreement or disagreement with the statements; 66% concordance with the statements was needed to define a consensus.

RESULTS

Consensus was reached on 78% of statements. There was a strong consensus on the mechanism of action of heat on muscle, the indication in chronic MP, its effectiveness as part of a multimodal approach to MP and the safety and tolerability of superficial heat therapy. A low-level of consensus was obtained on the role of heat in preventing muscular damage and in acute MP.

CONCLUSION

This Delphi consensus recognizes the role of HT mostly in chronic MP and highlights the need for stronger scientific evidence to regulate the use of this therapy in clinical practice.

Pain provocation tests and clinical entities in male football players with longstanding groin pain are associated with pain intensity and disability

BACKGROUND

Clinical examination of male football players with longstanding groin pain can be considered difficult. Pain provocation tests are used to examine and classify longstanding groin pain into clinical entities as adductor-, iliopsoas-, inguinal-, and pubic-related. It is unknown if pain provocation tests and clinical entities are associated with pain intensity and disability.

OBJECTIVES

To investigate if the number of positive pain provocation tests and clinical entities are associated with pain intensity and disability, measured by the Copenhagen 5-Second Squeeze Test (5SST) and the Copenhagen Hip and Groin Outcome Score (HAGOS), respectively.

DESIGN

Cross-sectional.

METHOD

Forty male football players (age: mean 24 years [SD: 3.2]; height: mean 182 cm [SD: 5.7]; weight: mean 78 Kg [SD: 6.6]) with longstanding groin pain for a median of 8.5 months (IQR: 4-36) were included. The players underwent a bilateral groin examination with 33 pain provocation tests and were classified with clinical entities (0-7) based on the test findings.

RESULTS

The number of positive pain provocation tests (median 10, range 2-23) correlated with pain intensity (5SST: rs = 0.70 [95% CI: 0.50, 0.83]) and disability (HAGOS subscales Sport: rs =-0.62 [95% CI: -0.81, -0.36], Pain: rs = -0.38 [95% CI: -0.69, -0.06], Symptoms: rs = 0.52 [95% CI: -0.73, -0.24], ADL: rs = -0.48 [95% CI: -0.71, -0.18]). The number of clinical entities (median 3, range: 1-7) showed similar but weaker correlations to pain intensity and disability.

CONCLUSIONS

In male football players with longstanding groin pain, the number of positive pain provocation tests and clinical entities shows weak to strong correlations with pain intensity and disability. Consequently, when pain intensity and disability are severe, a higher number of pain provocation tests may be positive, and more clinical entities may be present.

Chronic pain and local pain in usually painless conditions including neuroma may be due to compressive proximal neural lesion

It has been unexplained why chronic pain does not invariably accompany chronic pain-prone disorders. This question-driven, hypothesis-based article suggests that the reason may be varying occurrence of concomitant peripheral compressive proximal neural lesion (cPNL), e.g., radiculopathy and entrapment plexopathies. Transition of acute to chronic pain may involve development or aggravation of cPNL. Nociceptive hypersensitivity induced and/or maintained by cPNL may be responsible for all types of general chronic pain as well as for pain in isolated tissue conditions that are usually painless, e.g., neuroma, scar, and Dupuytren's fibromatosis. Compressive PNL induces focal neuroinflammation, which can maintain dorsal root ganglion neuron (DRGn) hyperexcitability (i.e., peripheral sensitization) and thus fuel central sensitization (i.e., hyperexcitability of central nociceptive pathways) and a vicious cycle of chronic pain. DRGn hyperexcitability and cPNL may reciprocally maintain each other, because cPNL can result from reflexive myospasm-induced myofascial tension, muscle weakness, and consequent muscle imbalance- and/or pain-provoked compensatory overuse. Because of pain and motor fiber damage, cPNL can worsen the causative musculoskeletal dysfunction, which further accounts for the reciprocity between the latter two factors. Sensitization increases nerve vulnerability and thus catalyzes this cycle. Because of these mechanisms and relatively greater number of neurons involved, cPNL is more likely to maintain DRGn hyperexcitability in comparison to distal neural and non-neural lesions. Compressive PNL is associated with restricted neural mobility. Intermittent (dynamic) nature of cPNL may be essential in chronic pain, because healed (i.e., fibrotic) lesions are physiologically silent and, consequently, cannot provide nociceptive input. Not all patients may be equally susceptible to develop cPNL, because occurrence of cPNL may vary as vary patients' predisposition to musculoskeletal impairment. Sensitization is accompanied by pressure pain threshold decrease and consequent mechanical allodynia and hyperalgesia, which can cause unusual local pain via natural pressure exerted by space occupying lesions or by their examination. Worsening of local pain is similarly explainable. Neuroma pain may be due to cPNL-induced axonal mechanical sensitivity and hypersensitivity of the nociceptive nervi nervorum of the nerve trunk and its stump. Intermittence and symptomatic complexity of cPNL may be the cause of frequent misdiagnosis of chronic pain.

Physical properties and biological effects of ceramic materials emitting infrared radiation for pain, muscular activity, and musculoskeletal conditions

BACKGROUND

Up to 33% of the general population worldwide suffer musculoskeletal conditions, with low back pain being the single leading cause of disability globally. Multimodal therapeutic options are available to relieve the pain associated with muscular disorders, including physical, complementary, and pharmacological therapies. However, existing interventions are not disease modifying and have several limitations.

METHOD

Literature review.

RESULTS

In this context, the use of nonthermal infrared light delivered via patches, fabrics, and garments containing infrared-emitting bioceramic minerals have been investigated. Positive effects on muscular cells, muscular recovery, and reduced inflammation and pain have been reported both in preclinical and clinical studies. There are several hypotheses on how infrared may contribute to musculoskeletal pain relief, however, the full mechanism of action remains unclear. This article provides an overview of the physical characteristics of infrared radiation and its biological effects, focusing on those that could potentially explain the mechanism of action responsible for the relief of musculoskeletal pain.

CONCLUSIONS

Based on the current evidence, the following pathways have been considered: upregulation of endothelial nitric oxide synthase, increase in nitric oxide bioavailability, anti-inflammatory effects, and reduction in oxidative stress.

Effects of a Family Caregiver Care Programme in Musculoskeletal Pain and Disability in the Shoulder-Neck Region-A Randomised Clinical Trial

Life expectancy in Spain has increased and older people need more health care to improve their quality of life. The high demands of the population sometimes collapse health services, making them insufficient to cover their needs, which leads to the development of “non-professional caregivers”. These caregivers have suffered musculoskeletal injuries of the cervical spine and shoulders and should be guided and assessed on ergonomics, biomechanics, or kinesiotherapy. However, there are no interventions to help them care for themselves. This study presents the application of a physical exercise programme to prevent these disorders in women caregivers of dependent patients. It consists of a randomised controlled clinical trial with two groups: both received a family caregiver care programme, and the intervention group also received a physical therapeutic exercise programme for 12 weeks. A total of 62 caregivers completed the study, who were mostly daughters or wives of dependents. Of these, 70.97% presented a “moderate” pain intensity and a cervical disability of 13.72 ± 7.64 points in the NDI questionnaire in the initial evaluation. In the intervention group of caregivers, there was a significant decrease in the pain intensity and a significant increase (p < 0.05) in all cervical joint amplitude movements. Caregivers present a high prevalence of musculoskeletal disorders. The physical exercise programme was effective in reducing the intensity of pain, lumbar disability, and cervical disability of the family caregivers.

Comparison of the effect of psychosocial skills training on acute and chronic musculoskeletal pain intensity: The effectiveness of early intervention in the reduction of acute musculoskeletal pain

BACKGROUND

Pain, as a psychological experience, is caused by complex interactions among sensory-discriminative, motivational-affective, and cognitive-evaluative dimensions. The psychosocial approach is one of the important approaches in managing musculoskeletal pain in patients. Therefore, this study aimed to determine and compare the effects of psychosocial skills training on pain intensity in patients with acute and chronic musculoskeletal pain.

METHODS

In this quasi-experimental study, 64 patients with acute and chronic musculoskeletal pain were selected using convenience sampling. Both groups received psychosocial training in pain management in groups of 8-10 people over six 1-h sessions. The data were collected at baseline, after the intervention, and 3 months later using a numerical rating scale (NRS). Then, the data were entered into the SPSS 22 software and were analysed using descriptive and inferential statistics.

RESULTS

In this study, the mean age of the participants was 50.10 ± 10.63 years and 60.9% of them were female. Based on the results, time had a significant effect on pain intensity (p < 0.001), but the effect of group on pain intensity was not statistically significant (p = 0.07). The group × time effect on pain intensity was also statistically significant (p < 0.001).

CONCLUSION

Psychosocial training had a positive impact on the reduction of pain among the patients with acute and chronic musculoskeletal pain. Additionally, the training was more effective in patients with acute pain due to early training. These findings can help healthcare providers in the field of musculoskeletal pain management, especially in patients with acute pain.

Autonomic Nervous System Function and Central Pain Processing in People With Frozen Shoulder: A Case-control Study

OBJECTIVES

The pathophysiology of a frozen shoulder (FS) is thought to be related to chronic inflammation. Chronic inflammation may disturb the immune system and consequently the nervous system as part of an overarching system. The aim of this study was to determine the presence of disturbed autonomic nervous system function and altered central pain processing (CPP) in patients with FS. Secondarily, the presence of psychological variables (catastrophizing and hypervigilance) and self-reported associated symptoms of altered CPP in patients with FS were investigated.

METHODS

Patients with FS and healthy controls completed the Composite Autonomic Symptom Score (autonomic function) and underwent quantitative sensory testing to assess tactile sensitivity (ie, allodynia), pressure pain thresholds (PPTs, ie, hyperalgesia), temporal summation of pain, and Conditioned Pain Modulation (CPM). Psychological issues were explored with the Pain Catastrophizing Scale and the Pain Vigilance and Awareness Questionnaire, and self-reported symptoms associated with altered CPP were determined with the Central Sensitization Inventory.

RESULTS

Thirty-two patients with FS and 35 healthy controls were analyzed in the study. Patients with FS showed more self-reported autonomic symptoms and symptoms of altered CPP, higher levels of pain catastrophizing and hypervigilance, and are more sensitive to tactile touches and mechanical pressure compared with controls.

DISCUSSION

On the basis of the effect sizes, between-group differences in allodynia, hyperalgesia, catastrophizing, and hypervigilance were clinically relevant, but only local allodynia, hyperalgesia, catastrophizing, and hypervigilance were statistically different. Therefore, obvious altered CPP was not present at the group level in patients with FS compared with controls.

Depression and work productivity: insights from a longitudinal cohort study on digital care programs for Musculoskeletal conditions

BACKGROUND

Comorbidity between musculoskeletal (MSK) pain and depression is highly common and associated with greater symptom burden and greater loss of work productivity. Multimodal care programs tackling both physical and mental health components may maximize productivity recovery and return to work. Digital delivery of such programs can facilitate access, ensure continuity of care, and enhance patient engagement.

OBJECTIVE

Assess the impact of a completely remote multimodal digital care program (DCP) for MSK pain on mental health and work-related outcomes stratified by baseline depression levels.

METHODS

The present study is an ad-hoc analysis of an interventional, single-arm, cohort study of individuals with MSK pain undergoing a DCP. Three subgroups with different baseline depression severity levels were created based on the Patient Health Questionnaire (PHQ-9): cluster 1 (<5: minimal depression); cluster 2 (5-10: mild depression) and cluster 3 (≥10: moderate depression). The mean change between baseline and end-of-program (8-12 weeks) on depression, anxiety, fear-avoidance beliefs, work productivity and activity impairment and adherence was assessed across subgroups. Outcome changes were analyzed by latent growth curve analysis.

RESULTS

From a total of 7785 eligible participants, 6137 (78.8%) were included in Cluster 1, 1158 (14.9%) in cluster 2 and 490 (6.3%) in cluster 3. Significant improvements in depression and anxiety scores were observed in clusters 2 and 3 but not cluster 1, with average end-of-the program scores in clusters 2 and 3 below the initially defined cluster thresholds (5 and 10 for clusters 2 and 3, respectively). All clusters reported significant improvements in productivity impairment scores (mean changes from -16.82, 95%CI -20.32 to -13.42 in cluster 1 to -20.10, 95%CI -32.64 to -7.57 in cluster 3). Higher adherence was associated with higher improvements in depression in clusters 2 and 3, and with greater recovery in activities of daily living in cluster 3. Overall patient satisfaction was 8.59/10.0 (SD 1.74).

CONCLUSIONS

A multimodal DCP was able to promote improvements in productivity impairment scores comparable to those previously reported in the literature, even in participants with comorbid depression and anxiety. These results reinforce the need to follow a biopsychosocial framework to optimize outcomes in patients with MSK pain.

CLINICALTRIAL

ClinicalTrials.gov NCT04092946; https://clinicaltrials.gov/ct2/show/NCT04092946.

The Determinants and Effects of Chronic Pain Stigma: A Mixed Methods Study and the Development of a Model

People with chronic pain report experiencing stigma, but few studies have explored this in detail. This mixed-methods study aimed to investigate factors that contribute to chronic pain stigma, the effects of stigma, and to explore the stigma experiences of people with chronic pain. Participants were 215 adults with chronic pain who completed questionnaires assessing chronic pain stigma, opioid use, mental health conditions, pain, depression, disability and social support, and 179 also answered open-ended questions about stigma experiences. Linear regression and path analysis showed that greater stigma was experienced by those who used more opioids, had a mental health condition, viewed their pain as organic, and were unemployed. Stigma was associated with greater disability, depression and lower social support. Qualitative results supported quantitative findings, with 3 themes: 1. "Faking It": Others disbelieve pain and attribute it to drug seeking, laziness, or mental health problems, 2. A spectrum of stigma: Experiences of stigma vary from none to widespread, and 3. "I hide it well": Concealing pain and avoiding stigmatizing situations lead to isolation & disability. This study demonstrates the negative influence of stigma and presents a novel integrated model of chronic pain stigma which may be used to develop interventions.

The Effectiveness of Intermittent Fasting, Time Restricted Feeding, Caloric Restriction, a Ketogenic Diet and the Mediterranean Diet as Part of the Treatment Plan to Improve Health and Chronic Musculoskeletal Pain: A Systematic Review

Food strategies are currently used to improve inflammation and oxidative stress conditions in chronic pain which contributes to a better quality of life for patients. The main purpose of this systematic review is to analyze the effectiveness of different dietary strategies as part of the treatment plan for patients suffering from chronic pain and decreased health. PubMed, Web of Science, ProQuest, Scopus, Cumulative Index to Nursing & Allied Health Literature (CINAHL), Cambridge Core, and Oxford Academy databases were used to review and to appraise the literature. Randomized clinical trials (RCT), observational studies, and systematic reviews published within the last 6 years were included. The Physiotherapy Evidence Database (PEDro) scale, the PEDro Internal Validity (PVI), the Standard Quality Assessment Criteria for Evaluating Primary Research Papers from a variety of fields (QUALSYT), and the Quality Assessment Tool of Systematic Reviews scale were used to evaluate the risk of bias of the included studies. A total of 16 articles were included, of which 11 were RCTs and 5 were observational studies. Six of them showed an improvement in pain assessment, while two studies showed the opposite. Inflammation was shown to be decreased in four studies, while one did not show a decrease. The quality of life was shown to have improved in five studies. All of the selected studies obtained good methodological quality in their assessment scales. In the PVI, one RCT showed good internal validity, five RCTs showed moderate internal quality, while five of them were limited. Current research shows that consensus on the effects of an IF diet on pain improvement, in either the short or the long term, is lacking. A caloric restriction diet may be a good long term treatment option for people suffering from pain. Time restricted food and ketogenic diets may improve the quality of life in chronic conditions. However, more studies analyzing the effects of different nutritional strategies, not only in isolation but in combination with other therapies in the short and the long term, are needed.

Chronic Pain in Musculoskeletal Diseases: Do You Know Your Enemy?

Musculoskeletal pain is a condition that characterises several diseases and represents a constantly growing issue with enormous socio-economic burdens, highlighting the importance of developing treatment algorithms appropriate to the patient’s needs and effective management strategies. Indeed, the algic condition must be assessed and treated independently of the underlying pathological process since it has an extremely negative impact on the emotional and psychic aspects of the individual, leading to isolation and depression. A full understanding of the pathophysiological mechanisms involved in nociceptive stimulation and central sensitization is an important step in improving approaches to musculoskeletal pain. In this context, the bidirectional relationship between immune cells and neurons involved in nociception could represent a key point in the understanding of these mechanisms. Therefore, we provide an updated overview of the magnitude of the musculoskeletal pain problem, in terms of prevalence and costs, and summarise the role of the most important molecular players involved in the development and maintenance of pain. Finally, based on the pathophysiological mechanisms, we propose a model, called the “musculoskeletal pain cycle”, which could be a useful tool to counteract resignation to the algic condition and provide a starting point for developing a treatment algorithm for the patient with musculoskeletal pain.

The Neuroimmune Interplay in Joint Pain: The Role of Macrophages

Chronic pain associated with joint disorders, such as rheumatoid arthritis (RA), osteoarthritis (OA) and implant aseptic loosening (AL), is a highly debilitating symptom that impacts mobility and quality of life in affected patients. The neuroimmune crosstalk has been demonstrated to play a critical role in the onset and establishment of chronic pain conditions. Immune cells release cytokines and immune mediators that can activate and sensitize nociceptors evoking pain, through interaction with receptors in the sensory nerve terminals. On the other hand, sensory and sympathetic nerve fibers release neurotransmitters that bind to their specific receptor expressed on surface of immune cells, initiating an immunomodulatory role. Macrophages have been shown to be key players in the neuroimmune crosstalk. Moreover, macrophages constitute the dominant immune cell population in RA, OA and AL. Importantly, the targeting of macrophages can result in anti-nociceptive effects in chronic pain conditions. Therefore, the aim of this review is to discuss the nature and impact of the interaction between the inflammatory response and nerve fibers in these joint disorders regarding the genesis and maintenance of pain. The role of macrophages is highlighted. The alteration in the joint innervation pattern and the inflammatory response are also described. Additionally, the immunomodulatory role of sensory and sympathetic neurotransmitters is revised.

Nociceptors: Their Role in Body’s Defenses, Tissue Specific Variations and Anatomical Update

The human body is constantly under the influence of numerous pathological factors: both external and internal. These factors can be potentially harmful and are perceived as such with a specialized nervous system subunit: the nociceptive system. The functional unit of the nociceptive system is the nociceptor. Recent studies have shown that nociceptors play a crucial role in maintaining of defensive homeostasis (responsive, immune, behavioral). Nociceptors respond to potentially harmful stimuli within viscera, bones, muscles, skin and specialized sensory organs. They function as complex predictors of harm through formation of pain stimulus. Their function and structures vary within different tissues. This variability reflects the anatomical and pathological peculiarities of varying tissues. Nociceptors play a significant role in adaptive, protective and behavioral reactions. Their functional capabilities and vast spread throughout the body make them the main units of the body’s defense system, allowing us to interact with the inner and outer environments.

Relative Effect of Extracorporeal Shockwave Therapy Alone or in Combination with Noninjective Treatments on Pain and Physical Function in Knee Osteoarthritis: A Network Meta-Analysis of Randomized Controlled Trials

Extracorporeal shockwave therapy (ESWT) has been recommended for managing pain in patients with knee osteoarthritis (KOA). The difference in therapeutic effects between radial shockwave characteristics (RaSW) and focused shockwave characteristics (FoSW) with different energy levels for KOA remains controversial. The purpose of this network meta-analysis (NMA) was to identify the effects relative to the different ESWT regime and combination treatments on pain and functional outcomes in individuals with KOA. The randomized controlled trials (RCTs) which investigated the efficacy of RaSW, FoSW, and combination treatments in patients with KOA were identified by searches of electronic databases. The included RCTs were analyzed through NMA and risk-of-bias assessment. We analyzed 69 RCTs with a total of 21 treatment arms in the NMA. Medium-energy FoSW plus physical therapy, medium-energy acupoint RaSW plus Chinese medicine, and high-energy FoSW alone were the most effective treatments for reducing pain [standard mean difference (SMD) = -4.51], restoring function (SMD = 4.97), and decreasing joint inflammation (SMD = -5.01). Population area and study quality influenced the treatment outcomes, particularly pain. Our findings indicate that medium-energy ESWT combined with physical therapy or Chinese medicine is beneficial for treating pain and increasing function in adults with KOA.

Telerehabilitation of acute musculoskeletal multi-disorders: prospective, single-arm, interventional study

Background

Acute musculoskeletal (MSK) pain is very common and associated with impaired productivity and high economic burden. Access to timely and personalized, evidence-based care is key to improve outcomes while reducing healthcare expenditure. Digital interventions can facilitate access and ensure care scalability.

Objective

Present the feasibility and results of a fully remote digital care program (DCP) for acute MSK conditions affecting several body areas.

Methods

Interventional single-arm study of individuals applying for digital care programs for acute MSK pain. Primary outcome was the mean change between baseline and end-of-program in self-reported Numerical Pain Rating Scale (NPRS) score and secondary outcomes were change in analgesic consumption, intention to undergo surgery, anxiety (GAD-7), depression (PHQ-9), fear-avoidance beliefs (FABQ-PA), work productivity (WPAI-GH) and engagement.

Results

Three hundred forty-three patients started the program, of which 300 (87.5%) completed the program. Latent growth curve analysis (LGCA) revealed that changes in NPRS between baseline and end-of-program were both statistically (p < 0.001) and clinically significant: 64.3% reduction (mean − 2.9 points). Marked improvements were also noted in all secondary outcomes: 82% reduction in medication intake, 63% reduction in surgery intent, 40% in fear-avoidance beliefs, 54% in anxiety, 58% in depression and 79% recovery in overall productivity. All outcomes had steeper improvements in the first 4 weeks, which paralleled higher engagement in this period (3.6 vs 3.2 overall weekly sessions, p < 0.001). Mean patient satisfaction score was 8.7/10 (SD 1.26).

Strengths and limitations

This is the first longitudinal study demonstrating the feasibility of a DCP for patients with acute MSK conditions involving several body areas. Major strengths of this study are the large sample size, the wide range of MSK conditions studied, the breadth of outcomes measured, and the very high retention rate and adherence level. The major limitation regards to the absence of a control group.

Conclusions

We observed very high completion and engagement rates, as well as clinically relevant changes in all health-related outcomes and productivity recovery. We believe this DCP holds great potential in the delivery of effective and scalable MSK care.

Trial registration

NCT, NCT04092946. Registered 17/09/2019;

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-021-04891-5.

Current Treatment Options for Patients with Myotonic Dystrophy Type 2

Purpose of the review

Myotonic dystrophy types 1 and 2 are frequent forms of muscular dystrophies in adulthood. Their clinical differences need to be taken into account for the most appropriate treatment of patients. The aim of this article is to provide an overview on the current and upcoming therapeutic options for patients with myotonic dystrophy type 2 (DM2).

Recent findings

At the moment, no disease-modifying therapies are available for DM2; next-generation therapies may however be available in the near future. In the meanwhile, the symptomatic management of patients has greatly improved, thank to the production of consensus-based standards of care and the growing evidence of efficacy of anti-myotonic drugs, promising employment of cannabinoids for symptom’s relief, regular monitoring, and early detection of treatable extra-muscular manifestations.

Summary

The treatment of DM2 is currently symptomatic and relies on the coordinated intervention of a multidisciplinary team. It remains to be determined whether upcoming causal therapies for myotonic dystrophy type 1 will be applicable also in DM2.

Pain management in people with hemophilia in childhood and young adulthood

Introduction: People with hemophilia (PWH) commonly experience acute and chronic musculoskeletal pain during childhood and young adulthood, but their treatment is often inadequate.Areas covered: From 1 September 2020 to 15 April 2021, authors performed a literature search in PubMed and the Cochrane Library using 'hemophilia AND pain' as keywords. Authors found 1082 articles, 51 of which were chosen because we considered them to be intimately connected with the topic of this report. Multimodal pain treatment, including multimodal analgesia, physical and rehabilitation medicine (PRM), and psychological therapies (imagery or relaxation, hypnosis), is currently the most recommended treatment for PWH. In acute hemarthrosis, in addition to hematologic treatment and joint aspiration, paracetamol/acetaminophen should be prescribed if the pain is mild, metamizole if the pain is moderate, and soft opioids (codeine or tramadol) if the pain is severe. In cases of chronic musculoskeletal pain due to hemophilic arthropathy, paracetamol/acetaminophen, COX-2 inhibitors, PRM, intra-articular injections of some drugs (corticosteroids, hyaluronic acid, platelet-rich plasma, mesenchymal stem cells), radiosynovectomy and behavioral therapies are advised.Expert opinion: Management of musculoskeletal pain in children and young adults with hemophilia should employ multimodal pain treatment (multimodal analgesia, PRM, and psychological strategies).

New developments in myotonic dystrophies from a multisystemic perspective

PURPOSE OF REVIEW

The multisystemic involvement of myotonic dystrophies (DMs) intricates disease monitoring, patients' care and trial design. This update of the multifaceted comorbidities observed in DMs aims to assist neurologists in the complex management of patients and to encourage further studies for still under-investigated aspects of the disease.

RECENT FINDINGS

We reviewed the most recent studies covering pathogenesis and clinical aspects of extra-muscular involvement in DM1 and DM2. The largest body of evidence regards the cardiac and respiratory features, for which experts' recommendations have been produced. Gastrointestinal symptoms emerge as one of the most prevalent complaints in DMs. The alteration of insulin signaling pathways, involved in gastrointestinal manifestations, carcinogenesis, muscle function, cognitive and endocrinological aspects, gain further relevance in the light of recent evidence of metformin efficacy in DM1. Still, too few studies are performed on large DM2 cohorts, so that current recommendations mainly rely on data gathered in DM1 that cannot be fully translated to DM2.

SUMMARY

Extra-muscular manifestations greatly contribute to the overall disease burden. A multidisciplinary approach is the key for the management of patients. Consensus-based recommendations for DM1 and DM2 allow high standards of care but further evidence are needed to implement these recommendations.