Signs and Symptoms of Myofascial Pain: An International Survey of Pain Management Providers and Proposed Preliminary Set of Diagnostic Criteria

Myofascial pain syndrome in patients with cancer: a narrative review

PURPOSE

Myofascial pain syndrome (MPS) is a chronic musculoskeletal pain syndrome. The purpose of this review is to describe the epidemiological and treatment evidence and to address the future research agenda in patients with cancer.

METHODS

A narrative review of previous reports investigating the prevalence and treatment of MPS in the oncology field is presented. The target population is patients with cancer and cancer survivors.

RESULTS

There have been three prospective and two retrospective studies investigating the prevalence of MPS. MPS is as high as 38%-45% in patients with advanced or incurable cancer and 11.9%-44.8% in cancer survivors. A total of nine reports investigated the efficacy of the following interventions: trigger point injection (TPI), myofascial techniques and ischaemic compression. TPI has been reported to be effective in four observational studies. One randomised study reported the efficacy of myofascial techniques, but two randomised studies reported no added beneficial effects of it in breast cancer survivors. Two randomised studies investigated the efficacy of ischaemic compression, but the obtained results were contradictory.

CONCLUSIONS

MPS is highly prevalent. We should know that non-cancer pain is also common in both patients with cancer and survivors. In treating such pain, careful physical examination is essential. Then, non-pharmacological treatment should be considered as well as pharmacotherapy. As evidence regarding MPS in the oncology field is scarce, further research is warranted.

Acute Effects of the Dry Needling Session on Gastrocnemius Muscle Biomechanical Properties, and Perfusion with Latent Trigger Points - A Single-Blind Randomized Controlled Trial in Mixed Martial Arts Athletes

The study aimed to evaluate the immediate effects of a dry needling (DN) therapy session on biomechanical properties, muscle power, perfusion, and pressure pain threshold of the gastrocnemius muscle with latent trigger points. Twenty mixed martial arts athletes (MMA) were randomly divided into two groups: experimental (eDN, n = 10) and sham (qDN, n = 10) to undergo one session of DN either with a real or a qazi needle. The measurements were taken at rest, 1-5 minutes after the DN (Post1-5min) and 24h after the DN (Post24h). DN significantly increased the muscle perfusion (Post1-5min and Post24h, p < 0.001), reduced its tone (Post1-5min and Post24h, p < 0.001) and stiffness (Post1-5min, p < 0.05; Post24 h, p < 0.001), and improved its elasticity (Post1-5min and Post24h, p < 0.001). DN also caused a significant increase in pressure pain threshold (Post1-5min, p < 0.001; Post24h, p < 0.05) and in muscle power (Post24h, p < 0.01). The DN session increased the blood perfusion and improved the biomechanical properties of the gastrocnemius muscle, which led to improved muscle power. The DN also had an analgesic effect. These effects were maintained at 24 h, which suggests that DN could facilitate muscle recovery in a post-exercise period of MMA athletes.

Myofascial Trigger Point Identification in B-Mode Ultrasound: Texture Analysis Versus a Convolutional Neural Network Approach

OBJECTIVE

Myofascial pain syndrome (MPS) is one of the most common causes of chronic pain and affects a large portion of patients seen in specialty pain centers as well as primary care clinics. Diagnosis of MPS relies heavily on a clinician's ability to identify the presence of a myofascial trigger point (MTrP). Ultrasound can help, but requires the user to be experienced in ultrasound. Thus, this study investigates the use of texture features and deep learning strategies for the automatic identification of muscle with MTrPs (i.e., active and latent MTrPs) from normal (i.e., no MTrP) muscle.

METHODS

Participants (n = 201) were recruited from Toronto Rehabilitation Institute, and ultrasound videos of their trapezius muscles were acquired. This new data set consists of 1344 images (248 active, 120 latent, 976 normal) collected from these videos. For texture analysis, several features were investigated with varying parameters (i.e., region of interest size, feature type and pixel pair relationships). Convolutional neural networks (CNN) were also applied to observe the performance of deep learning approaches. Performance was evaluated based on the classification accuracy, micro F1-score, sensitivity, specificity, positive predictive value and negative predictive value.

RESULTS

The best CNN approach was able to differentiate between muscles with and without MTrPs better than the best texture feature approach, with F1-scores of 0.7299 and 0.7135, respectively.

CONCLUSION

The results of this study reveal the challenges associated with MTrP identification and the potential and shortcomings of CNN and radiomics approaches in detail.

Ultrasound-Guided Trigger Point Injections for the Treatment of Neck and Back Pain in the Emergency Department: A Randomized Trial

OBJECTIVES

Patients frequently present to the emergency department (ED) with neck or back pain, which can be difficult to treat. We sought to compare ultrasound-guided trigger point injection (TPI) to standard medications for patients with neck or back pain.

METHODS

We performed a single-center, open label, randomized controlled trial on ED patients with neck or back pain from myofascial pain syndrome comparing ultrasound-guided TPIs to those who received the combination of a nonsteroidal anti-inflammatory drug (NSAID) and a muscle relaxant (MR). The primary outcome of this study was the reduction in mean pain score at the time of ED disposition.

RESULTS

In total, we analyzed 196 patients. At the time of ED disposition, patients in the TPI group had a mean reduction in their pain scores of 45.0 mm as compared to 49.9 mm in the NSAID plus MR group (difference: 4.9 [95% confidence interval (CI) -3.0 to 12.7], P = .22). At the first reassessment, patients in the TPI group had greater pain reduction by 10.7 mm (95% CI 3.1 to 18.4). The rate of rescue therapy use was higher in the NSAID plus MR group (difference: 17.5% [95% CI 4.4 to 36.2]).

CONCLUSIONS

We found no difference in pain reduction at the time of ED disposition between patients randomized to the ultrasound-guided TPI group as compared to those who received an NSAID plus a MR. However, patients in the TPI group had greater pain reduction at the time of first reassessment and lower rates of rescue therapy use.

Proposal of a diagnostic algorithm for myofascial trigger points based on a multiple correspondence analysis of cross-sectional data

BACKGROUND

Myofascial trigger points (MTrPS), the morphological correlate of myfascial pain syndromes (MPS), contribute to the worldwide high chronic pain burden. However, uncertainty about MTrP diagnostic criteria remains. Aim of this cross-sectional study was to characterize clusters of diagnostic criteria assessable during physical examination that might guide MTrP diagnosis.

METHODS

Thirteen MTrP diagnostic criteria proposed in relevant literature were assessed by standardized examinations in the trapezius and levator scapulae muscles of 61 chronic pain patients undergoing an interdisciplinary pain assessment. Hierarchical cluster analysis from multiple correspondence analysis was applied to data of the four muscles separately. Examining physicians classified the findings as MTrP, sufficient for diagnosis of an MPS and/or relevant for the patients' pain condition.

RESULTS

Taut bands, hypersensitive spots within a taut band, nodules within a taut band and referred pain (classical diagnostic criteria) were most frequent (28-66% M. trapezius, 8-21% M. levator scapulae). Restricted range of motion, pain during contraction, pain exacerbation during emotional stress, muscular weakness, jump sign, local twitch response and autonomic phenomena (complementary diagnostic criteria) occurred in 2-25% and hypersensitive spots and nodules outside of a taut band in 2-7% of the cases. Four clusters emerged: (1) no or just one diagnostic criterion, mostly a taut band alone; (2) a hypersensitive spot and/or nodule outside of a taut band partly in combination with complementary diagnostic criteria; (3) at least two classical diagnostic criteria (mostly a taut band containing a hypersensitive spot) partly in combination with complementary diagnostic criteria; (4) at least two, rather three, classical diagnostic criteria always in combination with complementary diagnostic criteria. Referred pain was specific to cluster 3 and 4. Among classical diagnostic criteria, palpable nodules within a taut band contributed least, and among complementary diagnostic criteria, restricted range of motion and pain during contraction contributed most to data representation.

CONCLUSION

We propose that the definite diagnosis of an MTrP requires a hypersensitive spot potentially felt as a nodule located within a taut band in addition to either referred pain, a local twitch response or at least two complementary diagnostic criteria, whereby signs of muscular dysfunction take on greater importance.

Buccal acupuncture combined with ultrasound-guided dry needle-evoked inactivation of trigger points to treat cervical and shoulder girdle myofascial pain syndrome

BACKGROUND

Myofascial pain syndrome (MPS) is a common disease with easy persistence and recurrence. In clinical practice, although many methods have been adopted to prevent and treat MPS, the control of MPS is still not satisfactory.

OBJECTIVE

To compare the safety and effectiveness of buccal acupuncture, inactivation of trigger points (MTrPs), and their combination in the treatment of MPS.

METHODS

Two hundred MPS patients in the pain clinic were randomly divided into four groups (n= 50) to receive oral drugs (Group A), oral drugs + buccal needle (Group B), oral drugs + MTrP inactivation (Group C), or oral drugs + buccal needle + MTrP inactivation (Group D).

RESULTS

The visual analogue scale (VAS) and cervical range of motion (ROM) of Group D were significantly lower than those of the other three groups, and the pressure pain threshold (PPT) value of labelled MTrPs was significantly higher than those of the other three groups (P< 0.05). The excellent rate and total effective rate of Group D were significantly higher than those of the other three groups. Group C had the highest pain score and the lowest acceptance score. The results showed that buccal acupuncture combined with ultrasound-guided dry needle-evoked inactivation of MTrPs can significantly reduce the VAS score of MPS patients, improve the range of motion of the cervical spine, and improve patient satisfaction.

CONCLUSIONS

This study provides a highly accepted and satisfactory treatment for MPS, which is worthy of clinical promotion.

Combining Ozonated Autohemotherapy with Pharmacological Therapy for Comorbid Insomnia and Myofascial Pain Syndrome: A Prospective Randomized Controlled Study

Objective

To examine the efficacy and safety of ozonated autohemotherapy (O3-AHT) combined with pharmacological therapy for comorbid insomnia and myofascial pain syndrome (MPS).

Materials and Methods

One hundred and eighteen patients were randomly divided into two groups: the control group (N = 50) and the O3-AHT group (N = 53). Patients in both groups were given the same pharmacological management for three weeks. Patients in the O3-AHT group were treated with ozonated autohemotherapy (the concentration of ozone was 20 µg/ml in the first week, 30 µg/ml in the second week, and 40 µg/ml in the third week) combined with pharmacological therapy. Primary (the insomnia severity index (ISI) and visual analogue scale (VAS)) and secondary outcomes (the Epworth sleepiness scale (ESS), polysomnography data, the anxiety and preoccupation about sleep questionnaire (APSQ), the beck depression index (BDI), and the multidimensional fatigue inventory (MFI)) were examined at pretreatment, posttreatment, 1 month, and 6 months.

Results

Fifty patients in the control group and fifty-three patients in the O3-AHT group completed the study. In both groups, insomnia and pain symptoms were relieved significantly compared with pretreatment. Compared with the control group, the O3-AHT group had significantly improved sleep quality, pain, and negative mood at different time points. No adverse complications were observed in either group.

Conclusion

Compared with pharmacological therapy alone, ozonated autohemotherapy combined with pharmacological therapy can ameliorate insomnia, reduce pain intensity, improve negative mood, and alleviate fatigue more effectively without serious adverse complications.

Effect of ischemic compression on myofascial pain syndrome: a systematic review and meta-analysis

Background

Myofascial pain syndrome (MPS) is a condition with local and referred pain characterized by trigger points (taut bands within the muscle). Ischemic compression is a noninvasive manual therapy technique that has been employed for the treatment of MPS in past decades. However, little attention has been devoted to this topic.

Objectives

The present review was designed to explore the efficacy of ischemic compression for myofascial pain syndrome by performing a descriptive systematic review and a meta-analysis to estimate the effect of ischemic compression on MPS.

Methods

A systematic review and meta-analysis concerning randomized controlled trials (RCTs) with myofascial pain subjects who received ischemic compression versus placebo, sham, or usual interventions. Five databases (PubMed, The Cochrane Library, Embase, Web of Science, Ovid) were searched from the earliest data available to 2022.1.2. The standardized mean difference (SMD) and the 95% confidence interval (CI) were used for statistics. Version 2 of the Cochrane risk of tool 2 (RoB 2) was used to assess the quality of the included RCTs.

Results

Seventeen studies were included in the systematic review, and 15 studies were included in the meta-analysis. For the pressure pain threshold (PPT) index, 11 studies and 427 subjects demonstrated statistically significant differences compared with the control at posttreatment (SMD = 0.67, 95% CI [0.35, 0.98], P < 0.0001, I² = 59%). For visual analog scale (VAS) or numeric rating scale (NRS) indices, 7 studies and 251 subjects demonstrated that there was no significant difference between ischemic compression and controls posttreatment (SMD = − 0.22, 95% CI [− 0.53, 0.09], P = 0.16, I² = 33%).

Conclusion

Ischemic compression, as a conservative and noninvasive therapy, only enhanced tolerance to pain in MPS subjects compared with inactive control. Furthermore, there was no evidence of benefit for self-reported pain. The number of currently included subjects was relatively small, so the conclusion may be changed by future studies. Big scale RCTs with more subjects will be critical in future.

Assessing the efficacy and safety of Juan Bi Tang for dialysis-related myofascial pain in the fistula arm: Study protocol for a randomized cross-over trial

Background

Dialysis-related myofascial pain in hemodialysis (HD) patients is an important issue that is associated with many other psychosomatic problems. Effective interventions are required to alleviate pain in this group. Chinese herbal medicine (CHM) may be a potential therapeutic treatment for reducing pain. The aim of this study is to evaluate the effects of a classic CHM formula intervention on pain intensity, daily function, quality of life (QOL), and safety in patients receiving HD in a dialysis center within the context of southern Taiwan.

Methods

This will be a randomized, open label, cross-over trial with two parallel groups in a pre- and post-test study. Forty patients reporting myofascial pain related to the arteriovenous (AV) fistula in the arm during regular HD sessions will be recruited. Participants will receive 4 weeks of treatment with Juan Bi Tang (JBT) and 4 weeks of no treatment in a random order, separated by a washout period of 2 weeks. Treatment doses (3 g JBT) will be consumed thrice daily. The primary outcome measure will be the Kidney Disease Quality of Life 36-Item Short-Form Survey. Secondary outcomes will include the Fugl-Meyer Assessment-arm, Visual Analogue Scale (VAS) of pain, and grip strength. Outcomes will be collected before and after each intervention, for a total of four times per participant. The safety evaluation will focus on adverse events (AEs).

Discussion

This study will be the first to use CHM to treat patients receiving HD with dialysis-related myofascial pain in their fistula arm and to perform a complete assessment of the treatment, including records of QOL, arm function and muscle power, severity of pain, and safety. The results of the study will provide convincing evidence on the use of JBT as an adjuvant treatment for dialysis-related myofascial pain.

Trial registration

Clinicaltrials.gov registry (NCT04417101) registered 30 May 2020.

Relationships between alexisomia and the presence of latent trigger points in the upper trapezius of healthy volunteers

BACKGROUND

Alexisomia is characterized by difficulties in the awareness and expression of somatic feelings. Trigger points are classified into two types, active and latent, according to the presence or absence of identifying spontaneous pain.

OBJECTIVE

We aimed to examine the association between alexisomia and the presence of latent trigger points (LTrPs) in the upper trapezius of healthy volunteers.

METHODS

This study was designed as a cross-sectional survey. A correlation analysis between the Shitsu-Taikan-Sho Scale (STSS) and LTrPs was performed on 154 healthy volunteers. The LTrP odds ratio for healthy volunteers with alexisomia was selected as the primary endpoint.

RESULTS

LTrPs were seen in the upper trapezius of 82 healthy volunteers (53.2%). There was no significant difference between the LTrP and non-LTrP groups in STSS total score (p= 0.11). However, there was a significant difference between them in STSS difficulty of identifying bodily feelings (DIB) score (p= 0.03). In the alexisomic versus non-alexisomic groups, the LTrP odds ratio for STSS total score was 2.30 (95% confidence interval [CI] 1.03-5.10) and for STSS DIB score, 2.08 (95% CI 1.05-4.11).

CONCLUSIONS

In STSS DIB in particular, alexisomia was associated with the presence of LTrP in the upper trapezius of healthy volunteers.

Effect of visual feedback during ultrasound-guided hydrodissection for myofascial pain syndrome: An exploratory, prospective, observational clinical trial on the expectations for treatment

Expectations for treatment have a favorable effect on the subsequent course of pain and behavior in patients. It is not known whether receiving hydrodissection while patients view their ultrasound image with doctors (visual feedback) is associated with positive treatment expectations. This was an exploratory, prospective, observational clinical trial. We explored the possibility that visual feedback immediately after ultrasound-guided hydrodissection increases the expectations for treatment, which could be one of the related factors for pain reduction. Treatment expectations were set as mediators of pain using path analysis. The primary endpoint was the numerical rating scale to assess expectations for treatment immediately after hydrodissection, between with and without the visual feedback. During 2019 and 2020, 136 outpatients received ultrasound-guided hydrodissection for myofascial pain syndrome. Of these, 65 (47.8%) patients received visual feedback during ultrasound-guided hydrodissection. Compared with the non-visual feedback group, the visual feedback group had higher expectations for treatment immediately after hydrodissection, and their expectations were maintained at day 14 of treatment (p < 0.001). A numerical rating scale (NRS) to assess expectations for treatment was similar before hydrodissection and immediately after hydrodissection was 8.4 (standard deviations, 1.6) in the visual feedback and 5.9 (standard deviations, 2.6) in the visual feedback. The proportion of increased expectations immediately after hydrodissection was 90.8% (95% CI: 83.7-97.9) in visual feedback group and 38.0% (95% CI: 26.7-49.3) in non-visual feedback group (p < 0.001). In the visual feedback group, 67.7% of patients showed improvement in pain numerical rating scale score by 50% or more at day 14, whereas such improvement was observed in only 36.6% of the non-visual feedback group (p < 0.001). Based on path analysis, the visual feedback had the greatest influence on pain numerical rating scale reduction at 14 days, indirectly due to increased expectations for treatment as a mediator (β = 0.434). However, the adjusted R ² values, which is the overall fit of the model, was low at 0.298. Visual feedback during ultrasound-guided hydrodissection increases the expectations for treatment immediately after hydrodissection, which could be one of the related factors for pain reduction in patients with myofascial pain syndrome.

Prevalence of myofascial pain syndrome and efficacy of trigger point injection in patients with incurable cancer. A multicenter, prospective observational study. (MyCar study)

OBJECTIVE

Myofascial pain syndrome (MPS) is caused by overload or disuse of skeletal muscles. Patients with cancer are often forced to restrict their movement or posture for several reasons. The study was conducted to investigate the prevalence and risks of MPS in patients with incurable cancer. The efficacy of trigger point injection (TPI) was also explored.

DESIGN AND METHODS

This was a multi-center, prospective observational study. Patients with incurable cancer who started receiving specialist palliative care were enrolled. We investigated the MPS in this population and accompanying risk factors for restricting body movement. Pre- and post-TPI pain was also evaluated using a Numerical Rating Scale (NRS) in patients who received TPI. The primary outcome was the prevalence of MPS.

RESULTS

A total of 101 patients were enrolled from five institutions in Japan. Most of the patients (n = 94, 93.1%) had distant metastases and half of the patients (50, 49.5%) received anticancer treatment. Thirty-nine (38.6%) patients had MPS lesions at 83 sites. Multivariate analysis revealed that the significant risk factor for MPS was poor Performance Status (PS) (odds ratio 3.26, 95% confidence interval 1.18-9.02, p = 0.023).We performed TPI for 40 out of 83 MPS lesions. Mean NRS for MPS before TPI was 7.95, which improved to 4.30 after TPI (p < 0.001).

CONCLUSIONS

MPS was common in patients with incurable cancer and the risk factor identified in this study was poor performance status. TPI could be a treatment option.

The Usefulness of the Armchair Sign for the Diagnosis of Psychosomatic-Prone Myofascial Pain Syndrome in Patients with Incurable Cancer: A Secondary Analysis of a Prospective Multicenter Observational Clinical Study

Background: Because psychosomatic diseases are pathological conditions, it is difficult to identify their degrees. The armchair sign is a test used to assess voluntary muscle relaxation.

Objective: We aimed to evaluate the usefulness of the armchair sign for the diagnosis of psychosomatic-prone myofascial pain syndrome (MPS) in patients with incurable cancer.

Design: This was a secondary analysis of a prospective multicenter observational clinical study.

Setting/Patients: Patients with incurable cancer who were referred to palliative care services at five institutions in Japan between March 2018 and December 2018.

Results: A total of 101 patients were enrolled, of whom 44 met MPS diagnostic criteria. Of these, 27 patients (61.3%) had psychosomatic-prone MPS. There was a significant association between the armchair sign and psychosomatic-prone MPS (p = 0.002). Sensitivity and specificity were 40.7% (95% confidence interval [CI]: 18.0–63.4) and 100.0%, respectively. The area under the curve score was 0.704 (95% CI: 0.553–0.855).

Conclusions: The armchair sign may be useful as an ancillary test for the diagnosis of psychosomatic-prone MPS in patients with incurable cancer.

Trial Registration: UMIN000031338. Registered February 16, 2018.

Quantitative Ultrasound Texture Feature Changes With Conservative Treatment of the Trapezius Muscle in Female Patients With Myofascial Pain Syndrome

OBJECTIVE

We set out to assess whether quantitative ultrasound could be used to assess changes that occur after physical therapy in patients experiencing myofascial pain syndrome.

METHODS

We consecutively recruited female subjects experiencing myofascial pain syndrome of the neck and shoulder region and provided 10 sessions of conservative physical therapy. A control group was recruited for textural analyses. We measured change in pain ratings, range of motion, and ultrasound texture features before and after the intervention and after 3 mos.

RESULTS

We recruited 63 female myofascial pain syndrome subjects and 20 healthy controls. After treatment, the mean blob size (an ultrasound texture feature) value for each subject decreased from 30.84 ± 5.00 to 25.86 ± 5.67 on the right and decreased from 31.70 ± 5.51 to 28.08 ± 5.53 on the left (P < 0.0005). The blob count showed a significant increase only on the left side (P < 0.01). Corresponding to this were reductions in pain and disability scores after treatment and at 3 mos compared with retreatment (P < 0.0005 for all checkpoints). Cervical range of motion values were significantly increased only at 3 mos compared with pretreatment except for mean flexion range of motion.

CONCLUSIONS

Ultrasound texture feature of blob size and count changes correspond to routine clinical outcomes after conservative physical therapy of myofascial pain syndrome in female individuals.

Comparison of dry needling and kinesio taping methods in the treatment of myofascial pain syndrome: A single blinded randomised controlled study

OBJECTIVES

The aim of this study was to compare the effectiveness of kinesio taping (KT) and dry needling (DN) in the treatment of myofascial pain syndrome (MPS) of the trapezius muscle.

METHODS

The patients with MPS were divided into 3 groups as those who received exercise only (control group), those who received KT and exercise (KT group) and those who received DN and exercise (DN group) by using a sealed opaque envelope randomisation method. Visual Analog Scale (VAS), Pressure Pain Threshold (PPT), Neck Disability Index (NDI) and Global Perceived Effect Scale (GPES) were measured twice at baseline and at the end of the second week by blinded evaluator.

RESULTS

A total of 26 patients were assigned to KT group, 32 to DN group and 30 to control group. The results of the study showed that PPT, VAS and NDI scores were significantly improved in the KT (1.61 ± 1.25, -2.66 ± 1.24 and -7.08 ± 6.24, respectively) and DN (1.30 ± 1.13, -3.34 ± 1.40 and -10.63 ± 7.80 respectively) groups (P < .001 for all). In the control group, no significant improvement was found in the VAS (.10 ± 1.39) and NDI (-.83 ± 4.91) scores (P > .05), with a significant decrease in PPT (-.98 ± 1.92) (P = .014). KT and DN methods in MPS treatment have more positive effects in terms of pain, disability and global effect compared to the control group.

CONCLUSIONS

In the treatment of MPS, adding DN or KT to exercise programme may provide important contributions to the treatment.

Re-Examining Myofascial Pain Syndrome: Toward Biomarker Development and Mechanism-Based Diagnostic Criteria

PURPOSE OF REVIEW

We discuss the need for a mechanism-based diagnostic framework with a focus on the development of objective measures (e.g., biomarkers) that can potentially be added to the diagnostic criteria of the syndrome. Potential biomarkers are discussed in relation to current knowledge on the pathophysiology of myofascial pain syndrome (MPS), including alterations in redox status, inflammation, and the myofascial trigger point (MTrP) biochemical milieu, as well as imaging and neurophysiological outcomes. Finally, we discuss the long-term goal of conducting a Delphi survey, to assess the influence of putative MPS biomarkers on clinician opinion, in order to ultimately develop new criteria for the diagnosis of MPS.

RECENT FINDINGS

Myofascial pain syndrome (MPS) is a prevalent healthcare condition associated with muscle weakness, impaired mood, and reduced quality of life. MPS is characterized by the presence of myofascial trigger points (MTrPs): stiff and discrete nodules located within taut bands of skeletal muscle that are painful upon palpation. However, physical examination of MTrPs often yields inconsistent results, and there is no gold standard by which to diagnose MPS. The current MPS diagnostic paradigm has an inherent subjectivity and the absence of correlation with the underlying pathophysiology. Recent advancements in ultrasound imaging, systemic biomarkers, MTrP-specific biomarkers, and the assessment of dysfunction in the somatosensorial system may all contribute to improved diagnostic effectiveness of MPS.

Potential Role of MRI Imaging for Myofascial Pain: A Scoping Review for the Clinicians and Theoretical Considerations

The most common cause of chronic musculoskeletal pain is chronic myofascial pain syndrome (MPS). MPS often presents with increased muscle stiffness, and the myofascial trigger point (MTrP). Imaging modalities have been used to identify the MTrP, but their role in the detection and diagnosis of MPS remains unclear. The purpose of this review was to identify evidence in literature for the use of imaging in the role of classifying and explaining the physiology of MTrPs. Since few imaging techniques have been performed on MTrPs, we explored the imaging techniques that can effectively image complex skeletal muscle microstructure, and how they could be used. As part of a scoping review, we conducted a systematic search from three medical databases (CINAHL, EMBASE and MEDLINE) from year to year to analyze past MTrP imaging, as well as analyzing imaging techniques performed on the microstructure of muscle. Previously, ultrasound has been used to differentiate active, latent MTrPs, but these studies do not adequately address their underlying anatomical structure. MRI remains the standard method of imaging skeletal muscle. The existing MRI literature suggests that the DTI technique can quantify muscle injury, strain, and structure. However, theoretically, HARDI and DKI techniques seem to provide more information for complex structural areas, although these modalities have a disadvantage of longer scan times and have not been widely used on skeletal muscle. Our review suggests that DTI is the most effective imaging modality that has been used to define the microstructure of muscle and hence, could be optimal to image the MTrP. HARDI and DKI are techniques with theoretical potential for analysis of muscle, which may provide more detailed information representative of finer muscle structural features. Future research utilizing MRI techniques to image muscle are necessary to provide a more robust means of imaging skeletal muscle and the MTrP.

Expert consensus on the diagnosis and treatment of myofascial pain syndrome

Myofascial pain syndrome (MPS) is characterized by myofascial trigger points and fascial constrictions. At present, domestic and foreign scholars have not reached a consensus on the etiology and pathogenesis of MPS. Due to the lack of specific laboratory indicators and imaging evidence, there is no unified diagnostic criteria for MPS, making it easy to confuse with other diseases. The Chinese Association for the Study of Pain organized domestic experts to formulate this Chinese Pain Specialist Consensus on the diagnosis and treatment of MPS. This article reviews relevant domestic and foreign literature on the definition, epidemiology, pathogenesis, clinical manifestation, diagnostic criteria and treatments of MPS. The consensus is intended to normalize the diagnosis and treatment of MPS and be used by first-line doctors, including pain physicians to manage patients with MPS.

The Immediate Effect of Trigger Point Injection With Local Anesthetic Affects the Subsequent Course of Pain in Myofascial Pain Syndrome in Patients With Incurable Cancer by Setting Expectations as a Mediator

A trigger point injection (TPI) with local anesthetic in myofascial pain syndrome (MPS) often has the immediate effect of a decrease in pain. It is unknown whether the immediate effect of a decrease in pain affects the subsequent course of pain. It is also unknown whether expectations of a decrease in pain mediate such effects. We aimed to clarify how the effect of a decrease in pain immediately after TPI with local anesthetic affected the subsequent course of pain, and whether it increased expectations of a decrease in pain. This was a prospective, single-center, observational clinical trial. Patients with incurable cancer who visited the palliative care department and received TPI with local anesthetic for MPS were prospectively examined. We evaluated whether the immediate effect of a TPI with local anesthetic affects the subsequent course of pain in MPS by setting expectations as a mediator, using path analysis. From 2018 to 2020, 205 patients with incurable cancer received TPI for MPS. Of these, 58.1% of patients reported an immediate effect of decreased pain. Compared with the non-immediate effect group, the immediate effect group had higher expectations of a decrease in pain, and the higher expectation was maintained at 7 days (p < 0.001). The percentage of patients with pain reduction at 7 days after TPI was 88.2% in the immediate effect group and 39.5% in the non-immediate effect group (p < 0.001). The immediate effect of decreased pain had the greatest influence on pain reduction at 7 days, both directly (β = 0.194) and indirectly through increased expectations (β = 0.293), as revealed by path analysis. The effect of a decrease in pain immediately after TPI with local anesthetic affected the subsequent course of MPS pain in patients with incurable cancer by setting expectations as a mediator. There were limitations to the discussion of these findings because this was an observational study.

Criteria Used for the Diagnosis of Myofascial Trigger Points in Clinical Trials on Physical Therapy: Updated Systematic Review

OBJECTIVE

The objective of this study was to conduct an updated systematic review of diagnostic criteria for myofascial trigger points (MTrPs) used in clinical trials of physical therapy interventions from 2007 to 2019.

METHODS

MEDLINE and Physiotherapy Evidence Database (PEDro) were searched using the following MeSH keywords: "trigger points," "trigger point," "myofascial trigger point," "myofascial trigger points," "myofascial pain," and "myofascial pain syndrome." The MeSH keywords were combined by using Boolean operators "OR"/"AND." All physiotherapy clinical trials including patients with musculoskeletal conditions characterized by at least 1 active MTrP or latent MTrP in any body area were selected. We pooled data from an individual criterion and criteria combinations used to diagnose MTrPs. The protocol was developed in accordance with the PRISMA-P guidelines.

RESULTS

Of 478 possibly relevant publications, 198 met the inclusion criteria. Of these 198 studies, 129 studies (65.1%) stated specifically the diagnostic criteria used for MTrPs in the main text, 56 studies (28.3%) failed to report any method whereby MTrP was diagnosed, and 13 studies (6.6%) adopted expert-based definitions for MTrPs without specification. Of 129 studies, the 6 criteria applied most commonly were: "spot tenderness" (n=125, 96.9%), "referred pain" (95, 73.6%), "local twitch response" (63, 48.8%), pain recognition (59, 45.7%), limited range of motion" (29, 22.5%), and "jump sign" (10, 7.8%). Twenty-three combinations of diagnostic criteria were identified. The most frequently used combination was "spot tenderness," "referred pain," and "local twitch response" (n=28 studies, 22%).

CONCLUSIONS

A number of the included studies failed in properly reporting the MTrP diagnostic criteria. Moreover, high variability in the use of MTrP diagnostic was also observed. Spot tenderness, referred pain, and local twitch response were the 3 most popular criteria (and the most frequently used combination). A lack of transparency in the reporting of MTrP diagnostic criteria is present in the literature.

REGISTRY

This systematic review was registered under the Centre for Reviews and Dissemination, PROSPERO number: CRD42018087420.

Serum inflammatory and oxidative stress biomarkers levels are associated with pain intensity, pressure pain threshold and quality of life in myofascial pain syndrome

OBJECTIVES

We aimed to determine the serum concentrations of some inflammatory and oxidative stress biomarkers in relation with pain intensity and quality of life in patients with myofascial pain syndrome (MPS) compared to healthy controls. This study is a case-control study. The participants were selected from MPS patients who referred to rehabilitation outpatient clinics of the Tabriz University of Medical Sciences, Iran.

RESULTS

Serum hs-CRP (4.68 ± 4.36 vs. 2.92 ± 4.55 g/mlµ respectively, p = 0.011), phospholipase A2 (PLA2) (6.81 ± 2.22 vs. 4.73 ± 2.97 pg/ml respectively, p < 0.001) and malondialdehyde (MDA) (2.63 ± 0.71 vs. 1.98 ± 0.90 nmol/ml respectively, p < 0.001) levels were significantly higher and serum total antioxidant capacity (TAC) (2.46 ± 0.49 vs. 2.83 ± 0.82 mmol/L respectively, p = 0.011) and superoxide dismutase (SOD) (78.89 ± 37.93 vs. 154.25 ± 115.93 U/ml respectively, p < 0.001) levels were significantly lower in the MPS patients compared to healthy controls. Serum high-sensitivity C-reactive protein (hs-CRP) level was significantly and positively associated with resting (r = 0.349, p = 0.019), activity (r = 0.295, p = 0.049) and night pain (r = 0.304, p = 0.043) intensities, pressure pain threshold (PPT) (r = 0.210, p = 0.047) and pain duration (r = 0.283, p = 0.007). Serum TAC level was significantly and negatively associated with resting pain intensity (r = -0.312, p = 0.037). Some scales and subscales of quality of life were positively correlated with serum TAC level and negatively associated with serum hs-CRP and PLA2 levels.

Ultrasound-guided interventional procedures for myofascial trigger points: a systematic review

Myofascial pain syndrome (MPS) is characterized by the presence of clinically detected myofascial trigger points (MTrPs). Diagnostic ultrasound (US) has been proposed as a method to strengthen the reliability of MTrP localization, thus potentially improving the efficacy and safety profile of interventional procedures. The objective is to evaluate the benefit and safety profile of any US-guided interventional procedure for MPS. Medline, Embase, PubMed, the Allied and Complementary Medicine Database (AMED), and Web of Science were systematically searched from their inception to May 2020 for any randomized controlled trial that evaluated treatment benefit and safety of any US-guided interventional procedure for MPS. The primary outcome of interest was pain severity. Additional outcomes of interest were function and adverse effects. The risk of bias was assessed using the Risk of Bias V.2.0 tool. eleven studies met all inclusion and exclusion criteria. Two studies (n=174) with a high risk of bias revealed some evidence supporting US guidance over blinded interventions for improvement in pain and function. Eight studies (n=483) with varying risks of bias were of head-to-head comparisons of different US modalities. These studies revealed that US-guided local anesthetic injections were inferior to US-guided pulse radiofrequency and US-guided dry needling (DN). US-guided DN was also found to be superior to US-guided platelet-rich-plasma injections but inferior to US-guided miniscalpel. Meanwhile, one study (n=21) with some concerns of bias found that US-guided local anesthetic injections were superior to non-steroidal anti-inflammatory drugs for pain outcomes and fewer adverse events. All US-guided procedures resulted in zero or minimal self-limited adverse events. Issues with clinical relevance, limited sample sizes, and small point estimates warrant more high-quality research to better characterize the possible value of US-guided injections.

The Levels of Insulin-Like Growth Factor in Patients with Myofascial Pain Syndrome and in Healthy Controls

BACKGROUND

Insulin-like growth factor-1 (IGF-1) plays an important role in muscle maintenance and repair. The role of IGF-2 in the muscle is less clear.

OBJECTIVE

To compare the levels of IGF-1 and IGF-2 in participants with acute myofascial pain syndrome (MPS) versus healthy controls and to determine whether age, gender, body mass index (BMI), region of pain, and pain intensity are associated with IGF levels.

DESIGN

A case-control study design included a total of 74 participants.

SETTING

Hospital emergency department.

PARTICIPANTS

Participants presenting with acute MPS (n = 43) and non-MPS controls (n  =  31).

MAIN OUTCOME MEASURES

Serum IGF-1 and IGF-2 (pg/mL) were measured in participants with MPS within 24 hours of symptom onset, and in non-MPS controls. Group and gender differences in serum IGF-1 and IGF-2 were assessed, with group and gender as factors, while controlling for age and BMI.

RESULTS

The mean IGF-1 levels were not significantly different between MPS and controls (88 554.1, confidence interval [CI], 79 724.4-97 383.7 vs. 97 911.2, CI, 85 322.8-110 493.6). Significant differences were also not observed in IGF-1 levels between men and women with MPS nor between men and women in the control group. Mean levels of IGF-2 were significantly lower in patients with MPS than in controls (226 608.9, CI, 180 057.3-273 160.5 versus 460 343.9, CI, 387 809.4-532 878.2, P < .001). There were no significant gender differences in the levels of IGF-2 in patients with MPS. Mean IGF-2 levels (pg/mL) of men and women with MPS were lower (253 343.0, CI, 179 891.0-326 795.0, and 204 524.2, CI, 141 176.4-267 872.0, respectively) than those of healthy men and women (428 177.2, CI, 368 345.7-488 008.6, and 511 274.4, 355 178.6-687 370.1, respectively). Lower BMI and younger age were associated with higher levels of IGF-2. Pain intensity was associated with IGF-2 but not with IGF-1, whereas region of pain was not associated with either IGF-1 or IGF-2 levels.

CONCLUSIONS

IGF-2 levels were lower in patients with acute MPS versus healthy controls with no gender differences, and IGF-1 levels were not different among the groups. Future studies should investigate the role of IGF-2 in muscle maintenance and repair in MPS.

Clinical Characteristics of Myofascial Pain Syndrome with Psychological Stress in Patients with Cancer

Background: Despite the suggestion of a relationship between development or progression of myofascial pain syndrome (MPS) and psychological stress, few studies have reported its proportion or association with treatment efficacy. Objective: We aimed to investigate the proportion of MPS with psychological stress among cancer patients and to compare the efficacy of trigger point injection (TPI) in the same patients with/without psychological stress. Design: This was a prospective observational study. Setting/Patients: Participants were 205 patients with cancer who received TPIs for MPS at a hospital in Japan. Results: The proportion of patients with MPS and psychological stress was 0.57 (95% confidence interval [CI] 0.50-0.64). The TPI efficacy rate at seven days after treatment was 0.55 (95% CI 0.46-0.64) for patients with MPS and psychological stress and 0.82 (95% CI 0.74-0.90) for their counterparts without psychological stress (p < 0.004). The odds ratio for TPI efficacy seven days after treatment with psychological stress versus without psychological stress was 0.25 (95% CI 0.13-0.49). Conclusions: MPS was a clinical symptom of psychosomatic disorder in approximately half of our patients. The TPI efficacy for patients with MPS who had psychological stress was lower than for their counterparts without psychological stress. Trial registration: UMIN000041210. Registered 27 July 2020 (retrospectively registered).

Effects of Heating-Conduction Dry Needling Therapy on Rats with Chronic Myofascial Pain Syndrome

OBJECTIVE

This study aimed to investigate the effect of dry needling (DN) with 44°C heating on the pressure pain threshold (PPT) of rats with chronic myofascial pain syndrome (MPS) by regulating the transient receptor potential V1 channel.

METHODS

A total of 80 rats were divided into 5 groups: A, B, C, D, and E (16 in each group). The rats in Group A recovered naturally, while those in other groups received the DN treatment. The needles were heated to 40°C for the rats in Groups B and E and 44°C for the rats in Groups C and D. In addition, both Groups D and E received local capsaicin injection. PPTs of the gastrocnemius muscle and tolerance time of the plantar hot plate were measured before modeling, 1 day before the intervention, 24 hours after the intervention, and 7 days after the intervention.

RESULTS

PPTs of the gastrocnemius muscle for rats with MPS increased 7 days after DN and heating to 40°C. For the rats receiving DN at 44°C heating, PPTs increased 24 hours and 7 days after the intervention. Further, 44°C heating and capsaicin injection improved PPT. DN and 40°C heating followed by capsaicin injection improved PPT.

CONCLUSION

DN and 44°C heating had therapeutic effects on rats with MPS at 24 hours and at 7 days after the intervention. DN and 40°C heating had therapeutic effects 7 days after the intervention. DN and 44°C heating might exert therapeutic effects by regulating the transient receptor potential V1 channel.

Pragmatic Randomized Controlled Pilot Trial on Trigger Point Injections With 1% Lidocaine Versus Conventional Approaches for Myofascial Pain in the Emergency Department

BACKGROUND

Myofascial neck and back pain is an increasingly common chief symptom in the emergency department. Currently, there are no widely accepted conventional therapies, and there is little evidence on the efficacy of interventions such as trigger point injections (TPIs).

OBJECTIVE

This study evaluates whether TPIs with 1% lidocaine can improve myofascial back and neck pain compared with conventional therapies. Secondary outcomes include changes in length of stay and number of opioid prescriptions on discharge.

METHODS

This single-center, prospective, randomized, pragmatic trial was carried out in patients clinically determined to have myofascial back or neck pain. Patients were randomized into the experimental arm (TPI with 1% lidocaine) or the control arm (standard conventional approach). Numeric Rating Scores (NRS) for pain and additional surveys were obtained prior to and 20 min after the intervention.

RESULTS

The NRS for pain was lower in the TPI group compared with the control group after adjustment for initial pain (median difference -3.01; 95% confidence interval -4.20 to -1.83; p < 0.001). Median length of stay was 2.61 h for the TPI group and 4.63 h for the control group (p < 0.001). More patients in the control group (47.4%) were discharged home with an opioid compared with the TPI group (2.9%) (p < 0.001).

CONCLUSIONS

TPI is an effective method for managing myofascial pain in the emergency department. This study indicates it may improve pain compared with conventional methods, reduce length of stay in the emergency department, and reduce opioid prescriptions on discharge.

The Case for Comorbid Myofascial Pain-A Qualitative Review

Myofascial pain syndrome is widely considered to be among the most prevalent pain conditions, both in the community and in specialized pain clinics. While myofascial pain often arises in otherwise healthy individuals, evidence is mounting that its prevalence may be even higher in individuals with various comorbidities. Comorbid myofascial pain has been observed in a wide variety of medical conditions, including malignant tumors, osteoarthritis, neurological conditions, and mental health conditions. Here, we review the evidence of comorbid myofascial pain and discuss the diagnostic and therapeutic implications of its recognition.

Real-world Outcomes of Ultrasonography-guided Interventions in a Tertiary Hospital

BACKGROUND

Intervention under ultrasonography (US) guidance has become increasingly prevalent in recent years. This study aimed to assess the treatment response to US-guided musculoskeletal interventions in daily practice.

METHODS

This retrospective study sought to identify the treatment response to US-guided interventions in different tissues conducted between January 2017 and December 2018. The treatment response to various US-guided interventions in different tissues was recorded. The response was further classified into positive response and negative response according to the improvement of symptoms or satisfaction of the treatment.

RESULTS

Among the 605 interventions included for data analysis, a positive response rate of 81% was observed in this study for all US-guided interventions, ranging from 70% to 88% in different categories.

CONCLUSION

This real-world analysis demonstrated the effectiveness of various US-guided interventions without serious complications. We recommend US as a useful guidance for a variety of injections.

Expansion of 1 mL of Solution by Ultrasound-Guided Injection Between the Trapezius and Rhomboid Muscles: A Cadaver Study

OBJECTIVE

An ultrasound-guided interfascial injection, which targets the space between the epimysia, is often performed for myofascial neck and shoulder pain. However, the relationship between the injection volume and clinical effectiveness has been controversial. We conducted an anatomical study with cadavers to measure the distribution of a small amount of pigment solution injected into the interfascial space.

DESIGN

An experimental cadaveric study.

SETTING

An institutional clinical anatomy laboratory.

METHODS

We performed 20 ultrasound-guided injections with pigment solutions of 1.0 mL each into the space between the trapezius muscle and rhomboid muscle bilaterally on 10 cadaver specimens. Cadavers were then dissected and macroscopically evaluated for pigment distribution on the fascia of the muscular surfaces. The pigment distribution area of each injection site was visually confirmed and calculated using automatic area calculation software.

RESULTS

Pigment solution exclusively within the interfascial space was visually confirmed in 95% (19/20) of injection sites. The median pigmented surface area (interquartile range) was 24.50 (16.17-30.76) cm2 on the deep side of the trapezius muscle and 18.82 (13.04-24.79) cm2 on the superficial side of rhomboid muscle; these measurements were statistically significantly different (P = 0.033).

CONCLUSIONS

A pigment solution comprising as little as 1.0 mL injected under ultrasound guidance separated two adjacent muscles and spread to the wide area within the interfascial space. The difference in the pigment distribution area between the two adjacent muscles can be explained by the path made by the injection needle and several layers of fascia between the epimysium.

Intravenous Ketamine Infusion for Complex Regional Pain Syndrome: Survey, Consensus, and a Reference Protocol

OBJECTIVE

To find and reach a consensus on the usage of ketamine in the treatment of complex regional pain syndrome and to determine a reference protocol for future studies.

DESIGN

Three hundred fifty-one medical professionals participated in our survey on practice procedures, with 104 respondents providing information on their usage of ketamine for treating the pain associated with complex regional pain syndrome. Respondents answered questions about inpatient treatment, outpatient treatment, children vs adults, safety, and basic demographic information. An expert group then met to reach a consensus for a reference protocol.

RESULTS

There is a difference in how inpatients are treated compared with outpatients, making it necessary to have two different reference protocols. The duration of pain relief varied from one to 10 days to one to six months, with a correlation between the duration of pain relief and total infusion hours per round.

CONCLUSIONS

The consensus reference protocols are made up of nine recommended topics. Reference protocols need to be validated by extensive research before guidelines can be created.

Improving characterization and diagnosis quality of myofascial pain syndrome: a systematic review of the clinical and biomarker overlap with delayed onset muscle soreness

INTRODUCTION

Myofascial pain syndrome (MPS) is one of the most common conditions of chronic musculoskeletal pain, yet its mechanisms are still poorly understood. Delayed Onset Muscle Soreness (DOMS) is also a regional pain syndrome that has clinical similarities to MPS, but has been better investigated. Emerging research suggests that DOMS may be a valid experimental model for studying MPS; however, a comparison of the similarities and differences of these two conditions has previously not been performed. Herein, we aimed to identify the similarities and differences in the clinical features and biomarkers between DOMS and MPS in order to better define MPS and identify future areas of (DOMS-informed) MPS research.

EVIDENCE ACQUISITION

In order to identify similarities and differences in the clinical manifestation and biomarkers of DOMS and MPS, scoping literature searches were performed using Medline (1965-2019), Embase (1966-2019) and Central (1966-2019) databases. Fifty-three full-text articles were reviewed out of the 2836 articles retrieved in the search.

EVIDENCE SYNTHESIS

A scoping review of the literature demonstrated that DOMS and MPS similarly present as conditions of musculoskeletal pain that are associated with decreased strength and limited range of motion. However, while taut bands and discrete tender spots were described in DOMS, none of the studies reviewed have characterized whether these tender points represent the classic myofascial trigger point phenomenon observed in MPS. Certain systemic circulation biomarkers, including inflammatory cytokines and growth factors, were commonly elevated in MPS and DOMS; further research is needed to determine if other biomarkers that are currently characterized in DOMS are useful to enhance the clinical evaluation of MPS.

CONCLUSIONS

DOMS and MPS share clinical and biomarker similarities suggesting that DOMS may be a useful model for studying MPS.

THE ROLE of a BIKE FIT in CYCLISTS with HIP PAIN. A CLINICAL COMMENTARY

Hip pathology is common amongst athletes and the general population. The mechanics of cycling have the potential to exacerbate symptomatic hip pathology and progress articular pathology in patients with morphologic risk factors such as femoroacetabular impingement. A professional fit of the bicycle to the individual which aims to optimize hip joint function can allow patients with hip pathology to exercise in comfort when alternative high impact exercise such as running may not be possible. Conversely improper fit of the bicycle can lead to hip symptoms in otherwise healthy individuals who present with risk factors for hip pain. Accordingly a bike fit can form part of the overall management strategy in a cyclist with hip symptoms. The purpose of this clinical commentary is to discuss hip pathomechanics with respect to cycling, bicycle fitting methodology and the options available to a physical therapist to optimize hip mechanics during the pedaling action.

The Effect of Electric Stimulation Techniques on Pain and Tenderness at the Myofascial Trigger Point: A Systematic Review

BACKGROUND

Myofascial pain is a prevalent chronic pain disorder, affecting a large proportion of the general population. Electric stimulation techniques such as transcutaneous electric stimulation (TENS) and electroacupuncture have been shown to be effective for managing chronic pain conditions including myofascial pain. The goal of this study was to review the literature on the effectiveness of electric stimulation techniques on myofascial pain.

METHODS

A comprehensive systematic search of three databases-Medline, EMBASE, and Cochrane CENTRAL-was conducted using key words related to myofascial pain and trigger points, as well as various electric stimulation techniques. A total of 15 articles passed the inclusion and exclusion criteria for the study. Data were extracted from these studies and assessed qualitatively and quantitatively. Standardized mean differences (SMDs) were computed from pain intensity measures extracted from these studies. Subgroup analyses were performed to assess the effectiveness of treatment modality, number of treatment sessions, frequency of stimulation, location of treatment, and duration of treatment.

RESULTS

The SMD for electric stimulation techniques on reported pain intensity was significant (P = 0.03), as was the SMD for the electroacupuncture subgroup (P = 0.02); the TENS subgroups' effect was not significant (P = 0.17). The subgroup analyses tentatively suggest that frequency and number of treatments do not influence pain intensity, whereas the duration of treatment may have an effect. The qualitative results of this study revealed variability in the results among studies delivering TENS treatments.

CONCLUSIONS

Electric stimulation is effective at mitigating reported pain intensity at the location of the trigger point. Electroacupuncture presented with significant and larger effect sizes of improvement relative to TENS for reported pain intensity. Given that this review included a small number of studies, there is a need for additional research to confirm its findings. Additionally, studies assessing the parameters and physiological location of treatment are needed to inform the clinical use and recommendations of electric stimulation treatments.

Feasibility of a Support Vector Machine Classifier for Myofascial Pain Syndrome: Diagnostic Case-Control Study

OBJECTIVES

Myofascial pain syndrome (MPS) is the most common cause of chronic pain worldwide. The diagnosis of MPS is subjective, which has created a need for a robust quantitative method of diagnosing MPS. We propose that using a support vector machine (SVM) along with ultrasound (US) texture features can differentiate between healthy and MPS-affected skeletal muscle.

METHODS

B-mode US video data were collected in the upper trapezius muscle of healthy (29) participants and patients with active (21) and latent (19) MPS, using an acquisition method outlined in previous works. Regions of interest were extracted and filtered to obtain a unique set of 917 images where texture features were extracted from each region of interest to characterize each image. These texture features were then used to train 4 separate binary SVM classifiers using nested cross-validation to implement feature selection and hyperparameter tuning. The performance of each kernel was estimated on the data and validated through testing on a final holdout set.

RESULTS

The radial basis function kernel classifier had the greatest Matthews correlation coefficient performance estimate of 0.627 ± 0.073 (mean ± SD) along with the largest area under the curve of 91.0% ± 3.0%. The final holdout test for the radial basis function classifier resulted in 86.96 accuracy, a Matthews correlation coefficient of 0.724, 88% sensitivity, and 86% specificity, validating our earlier performance estimates.

CONCLUSIONS

We have demonstrated that specific US texture features that have been used in other computer-aided diagnostic literature are feasible to use for the classification of healthy and MPS muscle using a binary SVM classifier.

Ultrasound imaging for sarcopenia, spasticity and painful muscle syndromes

PURPOSE OF REVIEW

On the basis of its various advantages and the relevant awareness of physicians, ultrasound imaging has overwhelmingly taken its place in the scientific arena. This is true both from the side of daily clinical applications and also from the side of research. Yet, ultrasound provides real-time (diagnostic) imaging and (interventional) guidance for a wide spectrum of muscle disorders. In this regard, this review aims to discuss the potential/actual utility of ultrasound imaging in particular muscle disorders, that is, sarcopenia, spasticity and fibromyalgia/myofascial pain syndrome.

RECENT FINDINGS

Due to the aging population worldwide and the importance of functionality in the older population, mounting interest has been given to the diagnosis and management of sarcopenia in the recent literature. Likewise, several articles started to report that ultrasound imaging can be used conveniently and effectively in the early diagnosis and quantification of sarcopenia.For spasticity, aside from ultrasound-guided botulinum toxin injections, intriguing attention has been paid to sonographic evaluation of muscle architecture, echogenicity and elasticity in the follow-up of these chronic conditions.As regards painful muscle syndromes, quantitative ultrasound techniques have been shown to detect statistically significant differences between healthy controls and patients with myofascial pain syndrome.

SUMMARY

Ultrasound imaging seems to be a promising tool that indisputably deserves further research in the management of a wide range of muscle disorders. VIDEO ABSTRACT: http://links.lww.com/COSPC/A17.

Fibromyalgia and myofascial pain syndrome: Two sides of the same coin? A scoping review to determine the lexicon of the current diagnostic criteria

OBJECTIVE

Consistent terminology to describe the diagnostic criteria for fibromyalgia (FM) and myofascial pain syndrome (MPS) is required to address the reported inadequacies in diagnosis. The present review investigated intervention studies in FM and MPS populations to determine the lexicon of the current diagnostic criteria used to identify chronic musculoskeletal pain patients.

METHODS

Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we conducted a scoping review to review systematically the literature obtained from five scientific databases between 1997 and February 2017. Included studies consisted of intervention studies that involved symptomatic musculoskeletal pain patients, of any age or gender, presenting with FM or MPS. Included studies were evaluated for musculoskeletal condition and the diagnostic criteria used to identify patient conditions. Extraction of study criteria focused on whether diagnostic criteria were explicitly stated, the diagnostic criteria used, physical findings, symptomatic duration and the profession of the healthcare provider who confirmed diagnosis.

RESULTS

We identified 493 interventions, of which 410 were related to FM and 83 to MPS. The lexicon of the diagnostic criteria used for MPS tended to be less consistent in comparison to FM criteria, with notable differences in all comparative categories.

CONCLUSIONS

The current review identified inconsistencies associated with the lexicon of the diagnostic criteria used to diagnose FM and MPS, and showed that there is wide variability in the terminology currently being used. These findings may have important implications for future development of consistent criteria to diagnose FM and MPS patients accurately.

International Consensus on Diagnostic Criteria and Clinical Considerations of Myofascial Trigger Points: A Delphi Study

Objective

There is no consensus on the essential diagnostic criteria for diagnosing a trigger point (TrP). In fact, a variety of diagnostic criteria are currently being used. Our aim was to conduct a Delphi panel to achieve an international consensus on the cluster of criteria needed for the TrP diagnosis to reach a consensus on the definition of active and latent TrPs and to clarify different clinical considerations about TrPs.

Methods

Following international guidelines, an international three-round Delphi survey was conducted. Questions were created based on a systematic literature search of the diagnostic criteria for TrPs.

Results

Sixty experts from 12 countries completed all rounds of the survey. A cluster of three diagnostic criteria was proposed as essential for the TrP diagnosis: a taut band, a hypersensitive spot, and referred pain. Eighty percent of the experts agreed that the referred pain elicited by a TrP can include different sensory sensations and not just pain, that is, pain spreading to a distant area, deep pain, dull ache, tingling, or burning pain. Eighty-four percent of the international experts consistently answered that the main clinical differences between active and latent TrPs are the reproduction of any of the symptoms experienced by a patient and the recognition of pain. No specific location of the pain referral area and TrP location should be expected.

Conclusions

This Delphi panel has produced an expert-based standardized definition of a TrP with a discussion of the clinical components, including the definition of referred pain and the difference between active and latent TrPs, thereby providing a foundation for future research in MPS.

Effect of aerobic exercise in the treatment of myofascial pain: a systematic review

Myofascial pain is prevalent chronic pain disorder that is comorbid with many conditions. Strengthening and stretching exercises are capable of inducing hypoalgesic effects in people with myofascial pain syndrome. The goal of this systematic review was to summarize the effects of aerobic exercise on the management of myofascial pain. A comprehensive database search was conducted. A total of 1,331 articles were identified for review. One article was eligible for inclusion after full screening. Risk of bias was assessed using the Downs and Black quality assessment questionnaire (1998). Mean difference scores were calculated for continuous variables. The identified study had a low risk of bias. It was a randomized controlled trial assessing the influence of an 8-week water aerobic exercise program on myofascial pain in breast cancer patients. Visual analogue scale pain intensity ratings and the number of myofascial trigger points present in the neck and shoulder/axillary area of participants significantly decreased in the exercise group compared to those in the control group. Pain pressure thresholds significantly increased in muscle areas of the cervical spine in the water exercise group. Aerobic exercise presents a potential treatment modality for managing myofascial pain. Additional research is necessary.

A critical overview of the current myofascial pain literature - November 2018

This is the first issue of this review column since the passing of Dr. Leon Chaitow. We would like to take a brief moment to acknowledge how much his mentorship, friendship, and confidence have meant to us. Leon was a force in osteopathic and naturopathic medicine and his influence reaches to all corners of the musculoskeletal realm crossing over many disciplines through his lectures, workshops, and of course, his many books, editorials, and articles. In the foreword to one of his books, Jan Dommerholt wrote that "Leon Chaitow […] continued the work of Travell and Simons, but also of many others, whose contributions he has skillfully woven into an intricate tapestry of clinical pearls, practical tips, and solid evidence-informed research." Dr. Chaitow was a synthesizer, who always considered what different clinicians and researchers could possibly contribute to a better understanding of pain and dysfunction and provide real solutions to real problems. Even when he would not necessarily agree with all suggested remedies, he maintained an open mind and was able to take a step back and consider the bigger picture. For example, Leon was not a big fan of dry needling, yet, he valued the importance of this approach and encouraged the inclusion of dry needling papers in this review article and in his journal. The Journal of Bodywork and Movement Therapies became his baby and, considering the growth of the journal, there is no question that Leon's intense focus and efforts are appreciated by many around the globe. We wish to extend our condolences to Leon's wife Alkmini and daughter Sasha. He will surely be missed, but we can find peace in knowing that his legacy will stay with us forever. In this issue, we have included several basic myofascial pain research articles. As usual, dry needling (DN) studies and case reports are the most commonly referenced papers, but we also included neuroscience and electromyography studies, sleep studies, interrater reliability studies, and case reports of adverse events.

Quantitative ultrasound of trapezius muscle involvement in myofascial pain: comparison of clinical and healthy population using texture analysis

PURPOSE

Ultrasound is a non-invasive quantitative method to characterize sonographic textures of skeletal muscles. To date, there is no information available on the trapezius muscle. This study assessed the trapezius muscles of patients with myofascial pain compared with normal healthy participants.

METHODS

The trapezius muscles of 15 healthy and 17 myofascial pain participants were assessed using B-mode ultrasound to obtain 120 images for healthy and 162 images from myofascial pain participants. Texture features such as blob area, count and local binary patterns (LBP) were calculated. Multi-feature classification and analysis were performed using principal component analysis (PCA) and MANOVA to determine whether there were statistical differences.

RESULTS

We demonstrate the two principal components composed of a combination of LBP and blob parameters which explain 92.55% of the cumulative variance of our data set. In addition, blob characteristics were significantly different between healthy and myofascial pain participants.

CONCLUSION

Our study provides evidence that texture analysis techniques can differentiate between healthy and myofascial pain affected trapezius muscles. Further research is necessary to evaluate the nature of these differences.

A Survey of Healthcare Practitioners on Myofascial Pain Criteria

OBJECTIVES

The goal of this study was to assess agreement on signs and symptoms of myofascial pain for chiropractors, physicians, and registered massage therapists.

METHODS

337 healthcare practitioners participated in the survey. The questionnaire probed clinician agreement with the chosen signs and symptoms using a 7-point agreement scale (1 = absolutely agree, 7 = absolutely disagree). Agreement was assessed using intraclass correlation within chiropractor, physician, and registered massage therapist groups and across all groups. Descriptive statistics, including mean response values, were used to assess which signs or symptoms were most often associated with myofascial pain.

RESULTS

There was poor agreement within chiropractors, physicians, and registered massage therapists on the criteria that represent myofascial pain syndrome. Physicians and massage therapists were in agreement on 4 items and disagreed on 2 items. Chiropractors were in agreement on a different set of signs and symptoms relative to physicians and registered massage therapists, and they expressed neutrality on most statements in the questionnaire. Registered massage therapists were in most agreement amongst each other as a group (intraclass correlation coefficient [ICC] = 0.80) relative to chiropractors (ICC = 0.59) and physicians (ICC = 0.51).

DISCUSSION

Our results suggest that there is a lack of agreement within and between healthcare practitioner groups on the signs and symptoms that define myofascial pain syndrome. We suggest the demonstrated variability in diagnostic knowledge be remedied through the establishment and universal use of official validated criteria. Future research should focus on developing criteria specific to myofascial pain syndrome. Finally, knowledge translation strategies may be implemented to increase clinician knowledge of available criteria.

Relationship between Alexithymia and latent trigger points in the upper Trapezius

Background

Latent trigger points (LTrPs) can be activated by future events, leading to pain. Few studies have reported LTrP risk factors. It has been suggested that alexithymia is associated with myofascial pain and diminished awareness of physical sensation. This study was designed to evaluate the relation between alexithymia and LTrPs found the upper trapezius of healthy individuals.

Methods

The correlation between LTrPs and alexithymia, and between LTrPs and depression was analyzed in 160 healthy participants (80 male, mean age: 40.5 years [20 to 66 years]). Each participant was evaluated for potential LTrPs by careful manual examination and completed the Toronto Alexithymia Scale-20 (TAS-20) and the Beck Depression Inventory (BDI) to assess potential alexithymia and depressive symptoms, respectively.

Results

LTrPs were observed in the upper trapezius of 76 participants (47.5%). TAS-20 scores were significantly higher in subjects with LTrPs than without LTrPs (p < 0.001); in contrast, there was no significant BDI score difference between these groups (p = 0.451). The LTrP risk for alexithymia was 2.74 (95% confidence interval [95% CI]: 2.10–3.58). There was no correlation between the TAS-20 and BDI scores (correlation coefficient: −0.04). Significant risk factors associated with LTrPs included the TAS-20 score (odds ratio [OR]: 1.11, 95% CI: 1.07–1.15) and age (OR: 1.05, 95% CI: 1.01–1.09).

Conclusions

Alexithymia was associated with LTrPs in the upper trapezius of healthy individuals, suggesting that it may serve as a useful predictive factor.

Trial registration

UMIN000027468. Registered 23 May 2017(retrospectively registered).

Prevalence of myofascial pain syndrome in patients with incurable cancer

BACKGROUND

Myofascial pain syndrome (MPS) is a condition that involves skeletal muscles. It is caused by overload or disuse of muscles and is characterized by extreme tenderness in the muscles with taut bands. Treatment for MPS is different from that for cancer-related pain. Cancer patients have many factors that cause restriction of body movement and posture. Although cancer patients appear to demonstrate risk factors for MPS, its prevalence has not been reported in patients with incurable cancer. This study was conducted to investigate the prevalence of MPS in patients with incurable cancer.

METHODS

A retrospective chart review. The data for patients with incurable cancer who received palliative care at our department between September 2015 and March 2016 were investigated. We examined the prevalence of MPS, which was diagnosed on the basis of the Rivers criteria (RC) and Simons criteria (SC). We also examined the following factors associated with MPS: performance status (PS), use of medical devices, and primary cancer sites. The primary outcome was the prevalence of MPS based on RC. Secondary outcomes included the prevalence of MPS based on SC and the relationship between MPS and either PS or medical devices.

RESULTS

Thirty-four patients with incurable cancer were identified. MPS based on RC or SC was detected in 10 (29%) and 20 (59%) patients, respectively. Twenty-two of 34 patients who complained of pain, 10 (45%) had MPS based on RC and 20 (90%) had MPS based on SC. Age and central venous port were risk factors for MPS by multivariate analysis.

CONCLUSION

A very high prevalence of MPS was detected in our study population. MPS should be considered when patients with incurable cancer complain of pain.