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

Scoping review and interpretation of myofascial pain/fibromyalgia syndrome: An attempt to assemble a medical puzzle

BACKGROUND

Myofascial Pain Syndrome (MPS) is a common, overlooked, and underdiagnosed condition and has significant burden. MPS is often dismissed by clinicians while patients remain in pain for years. MPS can evolve into fibromyalgia, however, effective treatments for both are lacking due to absence of a clear mechanism. Many studies focus on central sensitization. Therefore, the purpose of this scoping review is to systematically search cross-disciplinary empirical studies of MPS, focusing on mechanical aspects, and suggest an organic mechanism explaining how it might evolve into fibromyalgia. Hopefully, it will advance our understanding of this disease.

METHODS

Systematically searched multiple phrases in MEDLINE, EMBASE, COCHRANE, PEDro, and medRxiv, majority with no time limit. Inclusion/exclusion based on title and abstract, then full text inspection. Additional literature added on relevant side topics. Review follows PRISMA-ScR guidelines. PROSPERO yet to adapt registration for scoping reviews.

FINDINGS

799 records included. Fascia can adapt to various states by reversibly changing biomechanical and physical properties. Trigger points, tension, and pain are a hallmark of MPS. Myofibroblasts play a role in sustained myofascial tension. Tension can propagate in fascia, possibly supporting a tensegrity framework. Movement and mechanical interventions treat and prevent MPS, while living sedentarily predisposes to MPS and recurrence.

CONCLUSIONS

MPS can be seen as a pathological state of imbalance in a natural process; manifesting from the inherent properties of the fascia, triggered by a disrupted biomechanical interplay. MPS might evolve into fibromyalgia through deranged myofibroblasts in connective tissue ("fascial armoring"). Movement is an underemployed requisite in modern lifestyle. Lifestyle is linked to pain and suffering. The mechanism of needling is suggested to be more mechanical than currently thought. A "global percutaneous needle fasciotomy" that respects tensegrity principles may treat MPS/fibromyalgia more effectively. "Functional-somatic syndromes" can be seen as one entity (myofibroblast-generated-tensegrity-tension), sharing a common rheuma-psycho-neurological mechanism.

Dry needling increases antioxidant activity and grip force in a rat model of muscle pain

BACKGROUND

Muscle pain syndromes (MPS) are one of the main causes of functional, structural and metabolic problems, being associated with tissue oxidative damage. Although dry needling is widely used in the treatment of MPS, there is little scientific evidence of its efficacy and underlying mechanisms of action.

OBJECTIVES

To investigate the effects of different dry needling techniques on thermal and mechanical hyperalgesia, locomotor and functional activity, and oxidative stress markers in a rat model of muscle pain.

METHODS

A total of 48 male Wistar rats underwent injection of the gastrocnemius muscle with control neutral saline (pH 7) and remained untreated (Saline group), or acidic saline (pH 4) and remained untreated (ASA group) or received pregabalin (PG group), deep needling (DN group), superficial needling (SN group) or twitch needling (TN group) with n = 8 rats per group. Mechanical (von Frey test) and thermal hyperalgesia (acetone test), muscle edema (assessed with a caliper), strength and muscle function (grip force evaluation), surface thermography and locomotor and exploratory activities (open field test) were evaluated. The animals were then euthanized, and the gastrocnemius muscle was excised for assessment of oxidative analyses of lipid peroxidation with thiobarbituric acid reactive species (TBA-RS) and total glutathione (GSH) levels.

RESULTS

All treatments significantly improved muscle strength and function when compared to the AS group (p < 0.05). Pregabalin reduced locomotor and exploratory activities, while the TN intervention increased the antioxidant response (p < 0.05).

CONCLUSION

Dry needling improved strength, functionality and locomotor activity in a rat model of muscle pain. Twitch needling induced an antioxidant effect.

Is Instrumental Compression Equally Effective and Comfortable for Physiotherapists and Physiotherapy Students than Manual Compression? A Comparative Cross-Sectional Study

The objective of this work is to compare the homogeneity of instrumental and manual compression during the simulation of a pressure release technique, measured with a dynamometer, as well as to evaluate the comparative degree of comfort by physiotherapists and physiotherapy students when performing this technique. Methods: A comparative cross-sectional study was carried out with physiotherapists (lecturers with clinical experience) and 4th year students of the Physiotherapy Degree at Universidad San Jorge. The amount of pressure performed and how it was maintained during 80 s with both techniques was analysed using a digital dynamometer. The degree of comfort was evaluated using a modified numeric rating scale, with higher values representing a higher degree of discomfort. Results: A total of 30 subjects participated. Significant differences were found between the techniques in terms of maintaining a constant pressure level for 80 s (p = 0.043). A statistically significant difference was found between both techniques in the period from 45 to 80 s. Regarding the degree of discomfort, the value obtained from the students’ responses was 4.67 (1.35) for the manual technique and 1.93 (0.88) for the instrumental technique. In the case of physiotherapists, the comfort was 4.87 (2.13) for the manual technique and 3.33 (1.54) for the instrumental technique. Conclusion: The sustained manual compression necessary in manual pressure release techniques in the treatment of myofascial trigger points can be performed with assistive tools that guarantee a uniform compression maintained throughout the development of the technique and are more comfortable for physiotherapists.

Prognostic role of affected side of the sacroiliac joint in pain recurrence after total hip arthroplasty with prior manual correction of iliosacral dislocation: prospective randomized clinical study

INTRODUCTION

Degenerative changes in the hip joint as indications for operative treatment are observed in more than a third of the population over the age 50. In most cases, the development of a degenerative process in the hip joint is accompanied by changes in the sacroiliac joint. To improve the quality of life, relieve pain, and improve the clinical outcomes of rehabilitation after total hip arthroplasty (THA), an integrated approach should be chosen.

MATERIALS AND METHODS

Eighty-four patients were enrolled in a prospective randomized study, between 2017 and 2020. The patients were randomly (with the use of computer) divided into two groups (42 to group I, 42 to group II). The first group of patients underwent surgery using a new technique that included intra-operative manual correction of iliosacral dislocation of the sacroiliac joint, whilst the second group of patients underwent THA according to the standard protocol. All groups of patients underwent THA. Clinical treatment outcomes were assessed with the use of the Visual Analogue Scale (VAS) and the Harris Hip Score (HHS). Kaplan-Meier estimator was constructed to determine the differences in the probability of recurrence of pain syndrome depending on the side of the dislocated sacroiliac joint. NCT04673747 (ClinicalTrials.gov identifier).

RESULTS

There was a significant pain relief and an improvement in the quality of life of patients who underwent intra-operative manual correction of sacroiliac joint dislocation compared with the group of patients who underwent standard THA.

CONCLUSION

The use of intra-operative manual correction of sacroiliac joint dislocation can lead to a pronounced improvement in the quality of life of patients, pain decrease, and an improvement in rehabilitation of patients after performing THA. According to the analysis of statistical data, a potential risk factor for recurrence of pain, is the presence of dislocation on the contralateral side from the operated joint.

Immediate effects of variable durations of pressure release technique on latent myofascial trigger points of the levator scapulae: a double-blinded randomised clinical trial

OBJECTIVE

Latent myofascial trigger points (MTrPs) of the levator scapulae have a high prevalence and may influenceconditions of the neck and shoulder. The pressure release technique is one of the most recommended manual therapy techniques. The aim of this study was to determine the effect of varying durations of the pressure release technique application on latent MTrPs of the levator scapulae.

METHODS

In a three-arm (1:1:1 ratio), double-blinded, parallel, randomised clinical trial, 60 healthy university students (23 men, 37 women) with a mean±SD age of 20.0±2.67 years were recruited. Subjects were assigned to receive pressure release in one latent MTrP of the levator scapulae lasting 30s (T_30s; n=17), 60s (T_60s; n=22) or 90s (T_90s; n=21). Active cervical range of movement (CROM), strength, pressure pain threshold (PPT) and neck pain intensity at full stretch were measured immediately before and after treatment.

RESULTS

Mixed-model analyses of variance showed statistically significant differences for PPT (P=0.045; partial Eta²=0.103), comparing T_60s versus T_30s (P=0.009; Cohen's d=1.044) and T_90s versus T_30s groups (P=0.001; Cohen's d=1.253), and for left side bending strength (P=0.043; partial Eta²=0.105), comparing T_90s versus T_30s (P=0.023; Cohen's d=0.907). The rest of the comparisons did not present any significant differences (P⩾0.05).

CONCLUSIONS

The 60 s and 90 s applications of the pressure release technique may be recommended to increase PPT and strength, respectively, in latent MTrPs of the levator scapulae in the short term.

TRIAL REGISTRATION NUMBER

NCT03006822.

Ultrasound-Guided Dry Needling As a Treatment For Postmastectomy Pain Syndrome - A Case Series of Twenty Patients

CONTEXT

Existing interventions for postmastectomy pain syndrome (PMPS) address the neural component while overlooking a possible myofascial component.

AIM

The aim of the study is to investigate the myofascial contribution to PMPS, by examining the effectiveness of myofascial trigger point release by ultrasound-guided dry needling (USGDN).

PATIENTS AND METHODS

This retrospective review assessed the efficacy of USGDN in addressing myofascial pain in twenty consecutive patients with treatment-refractory PMPS. Patients in Group 1 (n = 16) received USGDN after neural interventions (NIs) such as neuraxial blocks, intrathecal pump implant, or pulsed radiofrequency, while those in Group 2 (n = 4) received USGDN alone. Outcome measures were changes in Numerical Rating Scale (NRS), PainDETECT (PD), Disabilities of Arm, Shoulder, and Hand (DASH), Patient Health Questionnaire-9 (PHQ-9) scores, and opioid use.

RESULTS

In Group 1, the mean (standard deviation) NRS and PD scores (9.6 [0.9] and 28.3 [4.3], respectively, at baseline) reduced to 5.2 (1.1) and 16.1 (3.7) at 1-week post-NI. The post-NI DASH reduction was below the cutoff for clinical relevance (80.9 [10.5] at baseline vs. 71.1 [10.5] post-NI). The opioid dose remained unchanged. Following USGDN, NRS, PD, and DASH scores further reduced to 2.3 (0.8), 6.6 (1.2), and 34.6 (14.4), respectively. Patients receiving USGDN alone also showed reduction in NRS, PD, and DASH (7.8 [1.7], 20.0 [8.0], and 61.0 [14.4] at baseline vs. 1.3 [0.5], 6.0 [1.6], and 22.5 [10.4] post-USGDN, respectively). In all patients, opioid use and PHQ-9 scores reduced only post-USGDN.

CONCLUSIONS

USGDN reduced pain, disability, and opioid use, whereas NI reduced only pain. This suggests a myofascial contribution to pain and disability in PMPS.