Mechanisms of Myofascial Pain

Sleep, Caffeine, BMI, and Pressure Pain Threshold in Temporomandibular Disorder Patients: An Observational Study

BACKGROUND

Temporomandibular disorders (TMDs) represent a multifactorial condition involving a multitude of symptoms of the temporomandibular joint that emanates a series of distress. Understanding the relationship between these lifestyle factors and pain perception in TMD patients is essential for optimizing their management and care. This study delves into the intricate interplay between sleep, caffeine consumption, body mass index (BMI), and the potential effect on pressure pain threshold (PPT) values among individuals with TMDs.

MATERIALS AND METHODS

This is an observational study. Data were collected from a convenient sample of female patients at a single center in Riyadh city, between the ages of 20 and 50 years. The variables collected were based on an operator-designed questionnaire, the symptom questionnaire, and the Diagnostic Criteria for Temporomandibular Joint Disorders (DC/TMD).

RESULTS

A total of 139 participants were included in the study, appraising the occurrence of TMD and pain as per reports of caffeine intake and sleep duration. The observed outcomes indicate that the amount of sleep has a significant effect on the PPT values in TMD patients. This study highlights the substantial impact of sleep duration on lowering PPT values in individuals with TMDs. The findings highlight the importance of considering sleep duration and caffeine intake in the comprehensive management of TMD patients. There was no effect of BMI on this particular sample.

CONCLUSION

This study shows a positive correlation between sleep and pain and TMD, caffeine, and pain. A deeper understanding of these relationships could pave the way for more effective pain management strategies and personalized treatment approaches tailored to the unique needs of TMD patients. BMI had no effect.

Superficial fascia displacement in cervical flexion: differentiating myofascial pain syndrome, a cross-sectional study

CONTEXT

Myofascial pain syndrome (MPS) is primarily characterized by myofascial trigger points related to fascial adhesions. MPS hinders fascial flexibility and mobility, leading to myofascial limitations, dysfunctional movement, and limitation of motion (LOM).

OBJECTIVES

This study determined the association of age, sex, type of work, symptom chronicity, symptom laterality, cervical LOM, altered direction of fascial displacement, and magnitude of superficial fascial displacement during active cervical flexion with the clinical diagnosis of MPS.

METHODS

A cross-sectional study selectively included MPS and non-MPS participants from different workplaces from January to October 2019. The MPS group exhibited clinical symptoms like tender spots, recognized pain patterns, and local twitch response upon palpation, often accompanied by cervical LOM. The non-MPS group lacked these symptoms, and those with certain pre-existing conditions or recent physiotherapy were not part of the study. Participants performed cervical active range of motion (AROM) while a sonographer recorded superficial fascial displacement utilizing ultrasound, which was later analyzed by three physiotherapists with the Tracker. Aiming for a multiple regression R-squared of 0.2, the target was 384 participants to account for a 20 % dropout, resulting in 307 participants after attrition. To explore the relationships between MPS and various factors, logistic regression models, rigorously tested for reliability and validity, were utilized.

RESULTS

In the study, there were 192 participants with MPS and 137 without MPS. The median ages were 33 years for the non-MPS group and 38 years for the MPS group. The adjusted model found significant links for sex (odds ratio [OR]=2.63, p<0.01), symptom chronicity (OR=8.28, p<0.01), and cervical LOM (OR=3.77, p=0.01). However, age and the presence of nodules/taut bands were not statistically significant (p>0.05). Also, the type of work, the direction of fascial displacement, and the difference in superficial fascial displacement during cervical flexion did not show a significant association with the clinical diagnosis of MPS (p>0.05). The adjusted model had a sensitivity of 73.80 % and a specificity of 81.34 %, correctly identifying 84.66 % of positive cases and 68.99 % of negative ones, resulting in an overall accuracy of 76.95 % in predicting MPS.

CONCLUSIONS

We provided an in-depth examination of MPS, identifying sex, duration of symptoms, and cervical LOM as significant predictive factors in its diagnosis. The study emphasizes the critical role of these variables in the accurate diagnosis of MPS, while delineating the comparatively minimal diagnostic value of other factors such as age, type of occupation, presence of nodules or taut bands, and variations in fascial displacement. This study underscores the imperative for further scholarly inquiry into the role of fascial involvement in musculoskeletal disorders, with the objective of enhancing both the theoretical understanding and diagnostic practices in this medical domain.

Is Dry Needling Treatment an Extra Contribution to Conventional Treatment for Hemiplegic Shoulder Pain? A Prospective, Randomized Controlled Study

Objective

This research was conducted to evaluate the effect of adding dry needling (DN) treatment to conventional rehabilitation for pain, range of motion (ROM), and functionality in patients with hemiplegic shoulder pain (HSP).

Materials and Methods

Patients with HSP (n = 38) were divided into 2 groups. A multimodal rehabilitation protocol, including physical therapy and exercise treatments, was given to both groups (5 sessions per week for 15 sessions). In addition to this rehabilitation, 3 sessions of DN therapy were given to one of the 2 groups. Measurements were a visual analogue scale; ROM; and 2 other scales (Quick Disability of the Arm, Shoulder, Hand; and the Fugl-Meyer Assessment Upper Extremity). Evaluations were made before, after, and at the third month after treatment.

Results

While a statistically significant improvement was seen in both groups in all parameters after their treatments, a statistical superiority was found in the conventional treatment+DN group (P < 0.05). However, the differences were not greater than the minimal clinically important difference values (MCID). At the 3rd month follow-up, there was no difference in pain and functionality parameters between the groups, while flexion and abduction measurements were higher in the conventional treatment+DN group (P < 0.05).

Conclusions

Adding DN treatment to conventional rehabilitation did not show any difference except in some joint ROM measurements in the subacute time. Although the changes found were statistically significant, they were not clinically significant as they did not reach MCID values.This study was registered prospectively at ClinicalTrials.gov (ref. no: NCT04790071).

Shock waves as treatment of mouse myofascial trigger points

INTRODUCTION

An abnormal increase in spontaneous neurotransmission can induce subsynaptic knots in the myocyte called myofascial trigger points. The treatment of choice is to destroy these trigger points by inserting needles. However, 10% of the population has a phobia of needles, blood, or injuries. Therefore, the objective of this study is to verify the usefulness of shock waves in the treatment of myofascial trigger points.

METHODS

Two groups of mice have been developed for this: healthy muscles treated with shock waves; trigger points affected muscles artificially generated with neostigmine and subsequently treated with shock waves. Muscles were stained with methylene blue, PAS-Alcian Blue, and labeling the axons with fluorescein and the acetylcholine receptors with rhodamine. Using intracellular recording the frequency of miniature endplate potentials (mEPPs) was recorded and endplate noise was recorded with electromyography.

RESULTS

No healthy muscles treated with shock waves showed injury. Twitch knots in mice previously treated with neostigmine disappeared after shock wave treatment. Several motor axonal branches were retracted. On the other hand, shock wave treatment reduces the frequency of mEPPs and the number of areas with endplate noise.

DISCUSSION

Shock waves seem to be a suitable treatment for myofascial trigger points. In the present study, with a single session of shock waves, very relevant results have been obtained, both functional (normalization of spontaneous neurotransmission) and morphological (disappearance of myofascial trigger points). Patients with a phobia of needles, blood, or injuries who cannot benefit from dry needling may turn to noninvasive radial shock wave treatment.

Comparison of the efficacy of oxygen-ozone and lidocaine injections in the treatment of myofascial pain syndrome: A randomized clinical trial

Objectives

This study aims to compare effectiveness of oxygen-ozone injection versus lidocaine injection on the trigger point in the treatment of myofascial pain syndrome (MPS).

Patients and methods

Between April 2021 and December 2021, a total of 46 patients with MPS (8 males, 38 females; mean age: 44.7±10.4 years; range, 25 to 65 years) were included. The patients were randomized to either ozone injection (n=23) or lidocaine injection (n=23) groups. All injections were administered once a week for three consecutive weeks. The primary outcome measure was the pain severity assessed by Visual Analog Scale (VAS). Secondary outcome measures were cervical lateral flexion range of motion (ROM), pain score (PS), and Neck Disability Index (NDI). The measurements were performed before the treatment, and at four and 12 weeks after treatment.

Results

There was a significant effect of time for VAS, PS, and NDI scores in both groups. Compared to baseline versus Weeks 4 and 12, the VAS, PS, and NDI scores significantly decreased over time in both groups (p<0.001 for all). A significant group X time interaction was identified regarding the VAS scores. The mean difference in the VAS scores over time was significantly higher in the lidocaine group compared to the oxygen-ozone group (p=0.028).

Conclusion

Oxygen-ozone and lidocaine injections of the trigger point can effectively improve pain and functional status. However, lidocaine injection appears to be superior in reducing pain compared to oxygen-ozone injection, but is not superior in improving function and PS.

Ultrastructure of Myofascial Trigger Points of Skeletal Muscles of Rats after Photobiostimulation with Low-Intensity Red Light

The effectiveness of low-intensity red light on myofascial trigger points in skeletal muscle of mature rats was evaluated by electron microscopy and high-resolution respirometry. The revealed changes in mitochondrial ultrastructure and activity of the respiratory chain enzymes indicate the development of hypoxia in the simulation area. Under the influence of low-intensity red light on myofascial trigger points, a decrease in the number of destructively altered muscle fibers and stimulation of mitochondrial respiration were found. These findings indicate intracellular regeneration and the stimulating effect of low-intensity red light on plastic processes.

Efficacy of botulinum toxin A injection in pelvic floor muscles in chronic pelvic pain patients: a study protocol for a multicentre randomised controlled trial

INTRODUCTION

Chronic pelvic pain (CPP) is a common multifactorial condition affecting 6%-27% of women aged 18-50 years worldwide. The aim of this randomised controlled trial (RCT) is to investigate the efficacy and safety of botulinum toxin A (BTA) injection compared with placebo injections in the pelvic floor muscles in women with CPP to improve pain, function and quality of life.

METHODS AND ANALYSIS

This is a study protocol for a multicentre, double-blinded placebo controlled RCT conducted in five gynaecology departments across the Netherlands. A total of 94 women over 16 years, with at least 6 months of CPP without anatomical cause and pelvic floor hypertonicity refractory to first-line pelvic floor physical therapy will be included. Participants will be randomised equally to BTA or placebo, both following physical therapy and (re-)education on the pelvic floor at 4, 8, 12 and 26 weeks after intervention. Multiple validated questionnaires focusing on pain, quality of life and sexual function will be collected at baseline and during all follow-up visits. Statistical analysis includes mixed models for repeated measurements.

ETHICS AND DISSEMINATION

Ethical approval (NL61409.091.17) was obtained from Radboud University Medical Research Ethics Committee (MREC) and Central Committee on Research involving human Subjects (CCMO). The findings will be presented through international conferences and peer-reviewed scientific journals.

TRIAL REGISTRATION NUMBER

EudraCT number (2017-001296-23), CCMO/METC number: NL61409.091.17.

Sensory and emotional responses to deep pressure stimulation at myofascial trigger points: a pilot study

Objective

Although manual pressure, such as that used during a massage, is often associated with pain, it can simultaneously be perceived as pleasant when applied to certain body areas. We hypothesized that stimulation of myofascial trigger points (TPs) leads to simultaneous pain and pleasure. TPs are hyperirritable points located in the taut band of the skeletal muscle.

Method

In this study, we measured the muscle tone, muscle stiffness, and pressure pain threshold of TPs and control points in the left brachioradialis muscle of 48 healthy participants. We also applied deep compression to the two points and collected subjective data on pain, pleasantness, unpleasantness, and relief.

Result

Greater muscle stiffness was observed in the TPs versus control points (t = 6.55, p < 0.001), and the pain threshold was significantly lower in the TPs (t = -6.21, p < 0.001). Unpleasantness ratings after deep compression were significantly lower in the TPs compared with control points (t = -2.68, p < 0.05). Participants experienced greater relief at the TPs compared with control points (t = 2.01, p < 0.05), although the perceived pain did not differ between the two types of points.

Conclusion

We compared the properties of TPs and control points, and found that deep compression at TPs was associated with higher muscle tone and stiffness, lower unpleasantness ratings, and higher relief ratings compared with the control points. These findings suggest that, at least for some TPs, pain and pleasantness are simultaneously elicited by deep pressure stimulation.

Creation of myofascial pain syndrome-like muscle by artificial electrical stimulation and stretching treatment

BACKGROUND

Myofascial pain syndrome（MPS）is a common chronic pain disorder characterized by muscle hardness, low extensibility, restriction of range of motion (ROM)　and pain with trigger point (TP). Eccentric contraction has been used in past animal studies of MPS. However, clinical experience suggests that concentric contraction is also involved in MPS formation.

NEW METHODS

In this study, we adopted artificial electrical stimulation to create artificial concentric contraction (ACC) in rat gastrocnemius muscle. After ACC, muscle hardness, torsion and range of motion (ROM) were compared between before ACC, after ACC, and stretching group. To clarify the association with pain, the expression of pERK in DRG were analyzed.

COMPARISON TO EXISTING METHODS

Previous animal studies have created MPS models by inducing eccentric contractions in muscles. In this study, full tetanus contraction of the gastrocnemius muscle was achieved via tibial nerve stimulation. This method substituted muscle contraction due to abnormal excitation.

RESULTS

We found that artificial abnormal contraction (ACC) induced muscle hardness and ROM restriction. The pERK expression in DRG was increased by ACC. Analysis of muscle tissue sections revealed a meandeling structure in muscle fibers. The stretching treatment improved these indicators. These results were similar to feature of the MPS muscles.

CONCLUSIONS

The ACC caused by artificial electrical stimulation leads to the characteristic of MPS in rat gastrocnemius muscle. This ACC model can be one of the useful options for MPS analysis.

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

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Comparative Efficacy of Platelet-Rich Plasma and Dry Needling for Management of Trigger Points in Masseter Muscle in Myofascial Pain Syndrome Patients: A Randomized Controlled Trial

AIMS

To compare the efficacy of platelet-rich plasma (PRP) injection vs dry needling (DN) for management of trigger points in the masseter muscle in myofascial pain syndrome (MPS) patients.

METHODS

This randomized controlled trial included 30 clinically confirmed cases of myofascial trigger points (MTrPs) in the masseter muscle who were randomly and equally (1:1) assigned to the test (PRP) and control (DN) groups. Both groups were evaluated for pain (visual analog scale [VAS]), range of functional movements, need for pain medication, patient satisfaction (Likert scale), and sleep (VAS) at baseline and 2-week, 1-month, and 3-month follow-ups. VAS pain and Likert score were also obtained at 6-month intervals.

RESULTS

The use of PRP solution in MTrPs in MPS patients had a better effect on pain and patient satisfaction compared to DN.

CONCLUSION

PRP appears to be a more effective treatment modality compared to DN in the management of MTrPs in MPS patients.

Sleep analysis results of portable polysomnography in patients with acute and chronic temporomandibular disorder

OBJECTIVE

This study aimed to investigate portable polysomnography (PSG)-based 'sleep' and pre-diagnosis of obstructive sleep apnoea (OSA) in acute temporomandibular disorder (TMD) and patients with chronic TMD.

METHODS

Randomly selected 25 patients with acute TMD (mean age, 42.58 ± 18.77 years; 14 females) and 26 age-and sex-matched patients with chronic TMD (mean age, 49.24 ± 17.52 years, 19 females) were enrolled.

RESULTS

The eight psychological subscales of SCL-90R had significantly higher values in the chronic TMD group than in the acute TMD group (all p < 0.05). There was no significant group difference in the respiratory event index examined using a portable PSG. OSA was observed in 57.7% in acute TMD, and 68.0% in chronic TMD, respectively. From the multiple regression analysis, palpation index was the strongest predictor of pre-diagnosis of OSA (OR = 17.550). Among the contributing factors for TMD, psychological stress (OR = 12.226), self-reported sleep problems (OR = 10.222), and above-average value of DEP (OR = 1.443) were followed.

CONCLUSION

Patients with chronic TMD were psychologically more vulnerable than those with acute TMD, and the existence of subjectively perceived sleep problems or objective sleep indices examined by portable PSG could affect TMD symptom severity in different ways.

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.

Dry Needling Produces Mild Injuries Irrespective to Muscle Stiffness and Tension in Ex Vivo Mice Muscles

Numerous studies have suggested that the myofascial trigger points are responsible for most of the myofascial pain syndrome, so it seems reasonable that its destruction is a good therapeutic solution. The effectiveness of dry needling (DN) has been confirmed in muscles with myofascial trigger points, hypertonicity, and spasticity. The objective of this study is to analyze the need of repetitive punctures on muscles in different situations. The levator auris longus (LAL) muscle and gastrocnemius muscle from adult male Swiss mice were dissected and maintained alive, while being submerged in an oxygenated Ringer’s solution. DN was evaluated under four animal models, mimicking the human condition: normal healthy muscles, muscle fibers with contraction knots, muscles submerged in a depolarizing Ringer solution (KCl-CaCl2), and muscles submerged in Ringer solution with formalin. Thereafter, samples were evaluated with optical microscopy (LAL) and scanning electron microscopy (gastrocnemius). Healthy muscles allowed the penetration of needles between fibers with minimal injuries. In muscles with contraction knots, the needle separated many muscle fibers, and several others were injured, while blood vessels and intramuscular nerves were mostly not injured. Muscles submerged in a depolarizing solution inducing sustained contraction showed more injured muscular fibers and several muscle fibers separated by the needle. Finally, the muscles submerged in Ringer solution with formalin showed a few number of injured muscular fibers and abundant muscle fibers separated by the needle. Scanning electron microscopy images confirm the optical analyses. In summary, dry needling is a technique that causes mild injury irrespective of the muscle tone.

The effect of one dry needling session on pain, central pain processing, muscle co-contraction and gait characteristics in patients with knee osteoarthritis: a randomized controlled trial

OBJECTIVES

To assess the immediate and three days postintervention effect of one dry needling session compared to one sham needling session on pain, central pain processing, muscle co-contraction and spatiotemporal parameters during gait in knee osteoarthritis patients.

METHODS

A double-blind randomized controlled trial was conducted. Sixty-one knee osteoarthritis patients were randomly assigned to the dry needling or sham needling group. Primary outcomes were pain and central pain processing. Secondary outcomes included muscle co-contraction and spatiotemporal parameters during gait. Patients were assessed at baseline and 15 min after the intervention, and pain also three days after the intervention. Linear mixed models were used to examine between- and within-group differences.

RESULTS

No significant between-group differences for pain were found, but within-group scores showed a significant decrease 15 min after sham needling and three days after dry needling. The mean conditioned pain modulation effect measured at the m. Trapezius worsened significantly 15 min after sham needling compared to after dry needling (between-group difference). However, individual conditioned pain modulation percentage scores remained stable over time. Various significant within-group differences were found 15 min after sham needling: a decrease of conditioned pain modulation measured at m. Quadriceps and m. Trapezius and stride- and step-time scores, and an increase in step length and widespread pain pressure threshold. A significant decrease in muscle co-contraction index of the m. Vastus Medialis and Semitendinosus was found as within-group difference 15 min after dry needling.

CONCLUSIONS

Dry needling has no larger effect on pain, central pain processing, muscle co-contraction and gait pattern 15 min and three days postintervention compared to sham needling. Mean conditioned pain modulation scores worsened after sham needling compared to after dry needling. Further research remains necessary.

The efficacy of botulinum toxin a injections in pelvic floor muscles in chronic pelvic pain patients: a systematic review and meta-analysis

Introduction and hypothesis

Chronic pelvic pain (CPP) is a common multifactorial condition affecting 6 to 27% of women aged 18–50 years worldwide. This study was conducted to review and meta-analyse the current literature on the reduction of chronic pelvic pain after botulinum toxin A (BTA) injection.

Method

In July 2021 we performed a systematic search in PubMed and EMBASE to assess the benefits of BTA injection in pelvic floor muscles in women with chronic pelvic pain. Primary outcome was reduction in visual analogue scale (VAS) after treatment. Secondary outcomes evaluated were: reduction of dyspareunia, pelvic floor resting pressure and quality of life. Identified reports were assessed on quality of reporting and risk of bias. Standardized mean difference (SMD) was used to combine and analyse outcomes of the included studies.

Results

Eight studies with 289 participants were considered eligible to be included in this systematic review and meta-analysis. After recalculating SMD into VAS scores (0–100), long-term follow-up (24–26 weeks) showed a significant 15-point improvement in VAS scores (95% CI: 8.8–21.5) for non-menstrual pelvic pain and a 13-point improvement (95% CI: 2.1–24.0) for dyspareunia. BTA injection had a significant effect on pelvic floor resting pressure and quality of life.

Conclusion

There is limited scientific evidence on the effectiveness of BTA injections in pelvic floor muscles in women with chronic pelvic pain. The available studies show that BTA injections significantly reduce pain levels and improve quality of life at 6 months follow-up.

Prospero ID

CRD42018105204.

Effect of myofascial release, stretching, and strengthening on upper torso posture, spinal curvatures, range of motion, strength, shoulder pain and disability, and quality of life in breast cancer survivors

BACKGROUND AND PURPOSE

Breast cancer survivors are known to develop upper torso pain and stiffness including shoulder elevation and ipsilateral inclination of the trunk within a short period of time as a result of cancer adjuvant therapies correlating with the type and side of surgery. Hence, the study.

METHODS

Twenty-two breast cancer survivors at a tertiary care hospital, Belgaum, Karnataka, have participated in this pre-post experimental study which included myofascial release (MFR), stretching, and strengthening for four sessions per week for 3 weeks that is, a total of 12 sessions. The participants were assessed at baseline and post-intervention using photogrammetry for Posture and shoulder range of motion (ROM), flexicurve for spinal curvatures, digital inclinometer for cervical ROM, manual muscle testing and hand dynamometer for strength of the upper back, shoulder muscles and hand grip, Shoulder Pain and Disability Index (SPADI) for shoulder impairment and Functional Assessment of Cancer Therapy-Breast (FACT-B) for quality of life.

RESULTS

The outcomes were analyzed with a p-value set at ≤0.05. The results of the study demonstrated a substantial improvement in the posture alignment (p = 0.001), shoulder and cervical ROM (p = 0.001), upper back and shoulder muscle and hand grip strength (p = 0.001), SPADI (p = 0.001), and FACT-B (p = 0.001) values.

DISCUSSION

The upper torso malalignment and muscular imbalance is seen in patients who has undergone surgeries involving the chest wall and early physiotherapy intervention can benefit the patients overall physical performance and quality of life. Hence, MFR, stretching and strengthening has shown to be beneficial in improving upper torso malalignment in breast cancer survivors.

IMPLICATIONS OF PHYSIOTHERAPY PRACTICE

The suggested techniques can be applied at a larger scale which can involve patients with head and neck cancer since the areas of intervention are identical. CTRI (Clinical Trial Registry- India) Registration No.: CTRI/2021/01/030453.

Positional release therapy and therapeutic massage reduce muscle trigger and tender points

OBJECTIVE

To determine if positional release therapy (PRT) or therapeutic massage (TM) was more effective in the treatment of trigger and tender points in the upper trapezius muscle.

BACKGROUND

Trigger points in the upper trapezius muscle are common and can be painful. Trigger points are commonly treated using TM however, PRT is a novel treatment that deserves further investigation.

METHODS

Sixty healthy male (24) and female (36) participants, (age = 27.1 ± 8.8 years, wt = 75.2 ± 17.9 kg, ht = 172.8 ± 9.7 cm) presenting with upper trapezius pain and a trigger point were recruited and randomized into either the TM or PRT group. Upper trapezius trigger points were found via palpation. Pain level was evaluated using a visual analog scale (VAS) and pain pressure threshold (PPT) was assessed using a pressure algometer. Muscle thickness was measured by B-mode ultrasound, while muscle stiffness was measured by shear-wave elastography (SWE). Participants were measured at baseline, posttreatment and again 48 h later.

RESULTS

Both treatments were effective in treatment of pain and muscle stiffness. Although no statistical group differences existed, treatment using PRT showed decreased pain averages and decreased pressure sensitivity at both post treatment, and 48 h later. Neither treatment was able to maintain the reduced muscle stiffness at the 48-h measure in males.

CONCLUSION

Both treatments showed a significant ability to reduce pain and acutely decrease muscle stiffness. Although not statistically different, clinically PRT is more effective at decreasing pain, and decreasing pressure sensitivity. Neither treatment method produced a long lasting effect on muscle stiffness in males.

Myofascial pain in temporomandibular disorders: Updates on etiopathogenesis and management

OBJECTIVES

Temporomandibular disorders (TMDs) are an umbrella term encompassing disorders of both the temporomandibular joint (TMJD) and masticatory musculature (MMD). The objective of this review is to provide an overview of the etiopathogenesis, clinical features and diagnosis of MMD, and to summarize the current trends in the therapeutic management.

METHODS

A review of the literature was performed from 1985 to 2020. The keywords included were "temporomandibular disorders OR temporomandibular joint disorders" AND "myofascial pain OR masticatory myofascial pain OR trigger point". A total of 983 articles were screened with abstracts and approximately 500 full text articles were included in the review based on their relevance to the topic.

RESULTS

MMD's present significant challenges in diagnosis and treatment. Effective treatment requires a clear diagnosis based on an understanding of pathophysiologic mechanisms, a detailed history with assessment of predisposing local and systemic factors, perpetuating factors, a comprehensive clinical evaluation and a diagnostic workup.

CONCLUSION

A thorough history and clinical examination are the gold standards for diagnosis of MMD. Serological testing may help identify underlying co-morbidities. Recent diagnostic modalities including ultrasound sonoelastography and magnetic resonance elastography (MRE) have shown promising results. The treatment goals for MMD are to control pain, restore mandibular function and facilitate the return to normal daily activity and improve the overall quality of life of a patient. Conservative modalities including home care regimens, pharmacotherapy, intraoral appliance therapy, local anesthetic trigger point injections, physiotherapy and complementary modalities may be beneficial in patients with MMD's.

Modified-Active Release Therapy in Patients with Scapulocostal Syndrome and Masticatory Myofascial Pain: A Stratified-Randomized Controlled Trial

Modified-active release therapy (mART) was developed to treat patients experiencing upper quarter pain. The objective of the study was to determine the effectiveness of the mART in treating pain, promoting function, and measuring emotions in patients with scapulocostal syndrome (SCS) and masticatory myofascial pain (MMP). A stratified-randomized controlled trial was employed in 38 participants separated into two groups. All participants underwent the same series visual analog scale (VAS), pressure pain threshold (PPT), mouth opening (MO), maximum mouth opening (MMO), craniovertebral angle (CV-angle), and pain catastrophizing scale Thai version (PCS-Thai-version) at the baseline. The mART group underwent the mART program three times a week for 4 weeks with a hot pack and an educational briefing while the control group received only a hot pack and the educational briefing. After treatment, both groups showed significant improvement (p < 0.05) in all parameters except MO, MMO, and CV-angle. When comparing outcomes between the groups, the mART group showed a statistically significant greater number of improvements than did the control group. In conclusion, the mART program can improve pain experienced by patients with SCS and MMP and it can be used as an adjuvant technique with conservative treatment.

Redox interactions of immune cells and muscle in the regulation of exercise-induced pain and analgesia: implications on the modulation of muscle nociceptor sensory neurons

The mechanistic interactions among redox status of leukocytes, muscle, and exercise in pain regulation are still poorly understood and limit targeted treatment. Exercise benefits are numerous, including the treatment of chronic pain. However, unaccustomed exercise may be reported as undesirable as it may contribute to pain. The aim of the present review is to evaluate the relationship between oxidative metabolism and acute exercise-induced pain, and as to whether improved antioxidant capacity underpins the analgesic effects of regular exercise. Preclinical and clinical studies addressing relevant topics on mechanisms by which exercise modulates the nociceptive activity and how redox status can outline pain and analgesia are discussed, in sense of translating into refined outcomes. Emerging evidence points to the role of oxidative stress-induced signaling in sensitizing nociceptor sensory neurons. In response to acute exercise, there is an increase in oxidative metabolism, and consequently, pain. Instead, regular exercise can modulate redox status in favor of antioxidant capacity and repair mechanisms, which have consequently increased resistance to oxidative stress, damage, and pain. Data indicate that acute sessions of unaccustomed prolonged and/or intense exercise increase oxidative metabolism and regulate exercise-induced pain in the post-exercise recovery period. Further, evidence demonstrates regular exercise improves antioxidant status, indicating its therapeutic utility for chronic pain disorders. An improved comprehension of the role of redox status in exercise can provide helpful insights into immune-muscle communication during pain modulatory effects of exercise and support new therapeutic efforts and rationale for the promotion of exercise.

Immediate Effects of Dry Needling on the Autonomic Nervous System and Mechanical Hyperalgesia: A Randomized Controlled Trial

BACKGROUND

Dry needling (DN) is often used for the treatment of muscle pain among physiotherapists. However, little is known about the mechanisms of action by which its effects are generated. The aim of this randomized controlled trial was to determine if the use of DN in healthy subjects activates the sympathetic nervous system, thus resulting in a decrease in pain caused by stress.

METHODS

Sixty-five healthy volunteer subjects were recruited from the University of Alcala, Madrid, Spain, with an age of 27.78 (SD = 8.41) years. The participants were randomly assigned to participate in a group with deep DN in the adductor pollicis muscle or a placebo needling group. The autonomic nervous system was evaluated, in addition to local and remote mechanical hyperalgesia.

RESULTS

In a comparison of the moment at which the needling intervention was carried out with the baseline, the heart rate of the dry needling group significantly increased by 20.60% (SE = 2.88), whereas that of the placebo group increased by 5.33% (SE = 2.32) (p = 0.001, d = 1.02). The pressure pain threshold showed significant differences between both groups, being significantly higher in the needling group (adductor muscle p = 0.001; d = 0.85; anterior tibialis muscle p = 0.022, d = 0.58).

CONCLUSIONS

This work appears to indicate that dry needling produces an immediate activation in the sympathetic nervous system, improving local and distant mechanical hyperalgesia.

Visualization of the epimysium and fascia thoracolumbalis at the lumbar spine using MRI

BACKGROUND

The fascia thoracolumbalis (FTL) is an important component for stabilization and motion control of the lumbar spine. It coordinates the traction forces of the autochthonous muscles of the back (AM) and connects them to the muscles of the abdominal wall, shoulder, and buttocks.

OBJECTIVES

The aim of our study was to describe the assessment of the normal FTL and epimysium of the AM in MRI and to identify patterns associated with pathological changes in the lumbar spine.

MATERIAL AND METHODS

A total of 33 patients were retrospectively evaluated: 15 patients had no pathology at the lumbar spine; six patients had previous hemilaminectomy, three had spondylodesis, two had ventrolisthesis, and seven had scoliosis. The thickness of the FTL and EM was measured, and the adhesion of both structures was assessed.

RESULTS

The fascial thickness at the levels of the lumbar vertebral bodies LVB 3 was 1.8, of LVB 4 it was 2.0, of LVB 5 it was 2.1, and at the sacral vertebra SVB 1 it was 1.8 mm. Fascial adhesions together with thickening of the EM occurred at the level of LVB 4 in 36% of the cases independently of the underlying disorder. Only thickening of the EM was seen in 48% of cases at the level of SVB 1. By contrast, adhesion of the FTL without epimysial changes occurred in 36% of cases at the level of LVB 3.

CONCLUSION

Thickening and adhesions at the EM and FTL occurred both postoperatively and in the case of scoliosis. Furthermore, lipomatous and muscular herniation could be detected in the FTL postoperatively. Epimysial and fascial alterations may be imaging manifestations of chronic myofascial back pain and should be included in radiological assessments.

Interventional Therapies for Pain in Cancer Patients: a Narrative Review

PURPOSE OF REVIEW

Pain is a prevalent symptom in the lives of patients with cancer. In light of the ongoing opioid epidemic and increasing awareness of the potential for opioid abuse and addiction, clinicians are progressively turning to interventional therapies. This article reviews the interventional techniques available to mitigate the debilitating effects that untreated or poorly treated pain have in this population.

RECENT FINDINGS

A range of interventional therapies and technical approaches are available for the treatment of cancer-related pain. Many of the techniques described may offer effective analgesia with less systemic toxicity and dependency than first- and second-line oral and parenteral agents. Neuromodulatory techniques including dorsal root ganglion stimulation and peripheral nerve stimulation are increasingly finding roles in the management of oncologic pain. The goal of this pragmatic narrative review is to discuss interventional approaches to cancer-related pain and the potential of such therapies to improve the quality of life of cancer patients.

A Biopsychosocial Model-Based Clinical Approach in Myofascial Pain Syndrome: A Narrative Review

One of the most common chronic musculoskeletal pain syndromes is myofascial pain syndrome (MPS). Trigger points (TrPs) are hypersensitive taut bands that appear in two genres, each with a different ratio in specific areas of the muscles, and when triggered, they can produce pain, numbness, and tingling. Various underlying causes (mechanical, nutritional, and psychological) have been discovered to participate in the pathogenesis of MPS, activating trigger points and intensifying the pain. Furthermore, genetic, social, and psychological factors seem to exacerbate these patients' clinical appearance, according to the biopsychosocial model, which seems to be closely linked to the formation of trigger points. Chronic pain and psychological distress frequently coexist, and psychological and social factors have been found to worsen the patient's quality of life and perpetuate the existing pain. The diagnosis is formed following a comprehensive physical and clinical examination, and the appropriate management technique is selected. For MPS treatment, management techniques based on the biopsychosocial model are used in conjunction with various myofascial release strategies and pharmacologic care. Exercise, posture correction, and a vitamin balance in the diet, especially in the Vitamin B complex, appear to prevent trigger point (TrP) activation. The precise etiology of MPS is not clear yet, and further research is needed to determine the root cause. A holistic approach, which blends the basic clinical care with the management of the biopsychosocial model, is essential to patients with MPS to regain their function and improve their quality of life and wellbeing.

Novel Functional Indices of Masticatory Muscle Activity

The aim of the present study was to analyze novel functional indices of masticatory muscle activity and compare them to existing and commonly used indices in patients with temporomandibular disorders (TMDs) and healthy adults. Based on the Research Diagnostic Criteria for Temporomandibular Disorders, 78 adult women qualified for the study. Subjects were divided into two groups: diagnosed TMDs (n = 36; mean age: 23.4 ± 2.6 years) and healthy adults (n = 42; mean age: 22.4 ± 2.3 years). Measurements of the bioelectric activity of the temporalis anterior (TA), superficial masseter (MM), and anterior bellies of the digastric muscle (DA) were carried out using the BioEMG III ™. Functional Clenching (FCI) and Functional Opening (FOI) indices were obtained as the ratio of the difference between the mean muscle root mean square (RMS) potentials during functional activity, including clenching (CL) and opening (MMO), and mean muscle resting (REST) potentials. Next, based on FCI and FOI indices, the Functional Clenching Activity Index (FCAI), Functional Clenching Symmetry Index (FCSI), and Functional Opening Symmetry Index (FOSI) were obtained. The statistical analysis showed significant differences in activity index left-sided (AcI_L) and Activity index both-sided (AcI_tot) between TMDs and healthy women during rest measurements. The significant differences between both groups were noted in terms of all Functional Clenching Indices except Functional Clenching Index for MM right-sided (FCI_MM-R). In all analyzed FCI indices, the control group showed higher values compared to the TMDs. Moreover, a significant difference between TMDs and controls was observed within Functional Clenching Activity Index left-sided (FCAI_L) (14.56 vs. −0.45, p = 0.01). Both functional indices, and asymmetry (AsI) and activity (AcI) indices seem to be reliable in assessing symmetry and activity within masticatory muscles. Further studies should be performed to verify the effectiveness and suitability of the assessment of masticatory muscles using functional indices.

Simple vacuum cup to identify the primary myofascial restriction: the root cause of pain elsewhere

Identification of the primary source of pain determines the success of musculoskeletal pain management. A detailed history and physical examination are the current gold standards for identifying musculoskeletal pain source in day-to-day clinical practice. This process, at times, may potentially result in inadequate/inappropriate identification of the pain source. In this case report, we present the usefulness of a simple and inexpensive vacuum cup. We found that this accurately identified the primary pain source, distant from and unrelated to the site of pain presentation in a 30-year-old man with back pain. Routine use of this simple technique in conjunction with the regular musculoskeletal examination may better identify primary restrictions in the body tissues. Based on our experience, we propose that this approach has the potential to offer better outcomes in the treatment of musculoskeletal pain in the future.

Evaluation of Soft Tissue Mobilization in Patients with Temporomandibular Disorder-Myofascial Pain with Referral

The aim of the study was functional evaluation of soft tissue mobilization in patients with temporomandibular disorder-myofascial pain with referral. The study group consisted of 50 individuals-37 females and 13 males. The average age was 23.36 ± 2.14 years. All subjects were diagnosed with myofascial pain with referral (diagnostic criteria for temporomandibular disorders). Soft tissue mobilization was applied three times. Electromyography of selected masticatory muscles was performed six times-before and after the treatment. After each mobilization, a decreasing tendency of muscular activity was observed in the entire study group. The Friedman test indicated that mobilization altered the activity of the right temporal muscle (p = 0.00010), both masseters (p = 0.0000), right sternocleidomastoid (p = 0.00251), left sternocleidomastoid (p = 0.00033), and right and left digastric muscles (p = 0.00045 and p = 0.00000, respectively). With respect to symmetry a statistically significant difference was noted in the case of the sternocleidomastoid muscles (p = 0.00729). In conclusion, soft tissue mobilization seems to be effective in the relaxation of masticatory muscles in patients with temporomandibular disorders. Our findings proved that soft tissue mobilization does not improve the symmetry and synergy of the masticatory muscles limited by dental occlusion.

Assessment of the effects of ischaemia/ hypoxia on angiogenesis in rat myofascial trigger points using colour Doppler flow imaging

Background & Aims

Myofascial pain syndrome (MPS) is a common non-articular disorder of the musculoskeletal system that is characterized by the presence of myofascial trigger points (MTrPs). Despite the high prevalence of MPS, its pathogenesis, which induces the onset and maintenance of MTrPs, is still not completely understood. To date, no studies have investigated the changes in the biochemical milieu caused by ischaemia/hypoxia in the MTrP regions of muscle that are proposed in the integrated hypothesis. Therefore, this study investigated whether ischaemic/hypoxic conditions participate in the formation of active MTrPs and affect angiogenesis using colour Doppler flow imaging (CDFI).

Methods

Twenty-five Sprague-Dawley rats were randomly divided into a model group and a normal control group. A model of active MTrPs was established by a blunt strike combined with eccentric exercise. Enzyme-linked immunosorbent assays (ELISAs) were employed to detect the levels of HIF-1α and VEGF. Microvessel density (MVD) was evaluated using immunohistochemistry. CDFI was applied to observe the blood flow signals in the MTrPs, which were classified into four grades based on their strengths.

Results

Compared with the control group, the active MTrP group exhibited significantly higher HIF-1α and VEGF levels and MVD values. These differences were accompanied by increased blood flow signals. In the active MTrP group, the blood flow signal grade was positively correlated with the MVD (P < 0.05) and independently correlated with the VEGF level (P < 0.05) but was not correlated with the expression of HIF-1α (P > 0.05).

Conclusion

Ischaemic/hypoxic conditions may be involved in the formation of MTrPs. CDFI is useful for detection of the features of angiogenesis in or surrounding MTrPs via assessment of blood flow signals.

Effect of Pressures and Durations of Cupping Therapy on Skin Blood Flow Responses

Cupping therapy has been widely used in treating musculoskeletal impairments. However, there is no specific guideline on selecting the intensity of cupping therapy, including the pressure and duration. The objective of this study was to investigate the effect of different pressures and durations of cupping therapy on skin blood flow responses. A 2 × 2 factorial design, including two negative pressures at -225 and -300 mmHg and two durations at 5 and 10 min, was tested in 12 healthy participants. The four protocols of cupping therapy were tested in four different days. Skin blood flow was measured using laser Doppler flowmetry on the left triceps (the SJ12 acupoint). Skin blood flow after cupping therapy was expressed as a ratio of skin blood flow before cupping therapy. The results showed that -300 mmHg caused a significant increase in peak skin blood flow (16.7 ± 2.6 times) compared to -225 mmHg (11.1 ± 2.2 times, p < 0.05) under 5-min duration. The largest difference in skin blood flow is between -300 mmHg for 5 min (16.7 ± 2.6 times) and -225 mmHg for 10 min (8.1 ± 2.3 times, p < 0.01). Our findings demonstrated that a higher value (300 mmHg) of negative pressure is more effective on increasing skin blood flow compared to a lower value (225 mmHg). Also, a shorter duration (5 min) causes a larger peak and total skin blood flow compared to a longer duration (10 min). This study provides the first evidence showing the effect of pressures and durations of cupping therapy on skin blood flow responses.

Influence of quantified dry cupping on soft tissue compliance in athletes with myofascial pain syndrome

PURPOSE

This study aimed to develop a quantitative dry cupping system that can monitor negative pressure attenuation and soft tissue pull-up during cupping to quantify soft tissue compliance.

METHODS

Baseball players with myofascial pain syndrome were recruited to validate the benefits of cupping therapy. Nine of 40 baseball players on the same team were diagnosed with trapezius myofascial pain syndrome; another nine players from the same team were recruited as controls. All participants received cupping with a negative pressure of 400 mmHg for 15 minutes each time, twice a week, for 4 weeks. Subjective perception was investigated using upper extremity function questionnaires, and soft tissue compliance was quantified objectively by the system.

RESULTS

During the 15-minute cupping procedure, pressure attenuation in the normal group was significantly greater than that in the myofascial group (p = 0.017). The soft tissue compliance in the normal group was significantly higher than that in the myofascial group (p = 0.050). Moreover, a 4-week cupping intervention resulted in an obvious increase in soft tissue lift in the myofascial pain group (p = 0.027), although there was no statistical difference in the improvement of soft tissue compliance. Shoulder (p = 0.023) and upper extremity function (p = 0.008) were significantly improved in both groups, but there was no significant difference between the two groups.

CONCLUSION

This quantitative cupping monitoring system could immediately assess tissue compliance and facilitate the improvement of soft tissues after cupping therapy. Hence, it can be used in athletes to improve their functional recovery and maintain soft tissues health during the off-season period.

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.

Acute Effect of the Compression Technique on the Electromyographic Activity of the Masticatory Muscles and Mouth Opening in Subjects with Active Myofascial Trigger Points

Active myofascial trigger points (MTrPs) in masticatory muscles are associated with a reduced range of motion and muscle weakness within the stomatognathic system. However, it is hard to identify the most effective treatment technique for disorders associated with MTrPs. The objective of this study was to analyze the acute effect of the compression technique (CT) on active maximal mouth opening (MMO) and electromyographic activity of the masseter (MM) and temporalis anterior (TA) muscles in subjects with active myofascial trigger points in the MM muscles. The study group comprised 26 women (mean age 22 ± 2) with bilateral active myofascial trigger points (MTrPs) in the MM. The control group comprised 26 healthy women (mean age 22 ± 1) without the presence of MTrPs in the MM. Masticatory muscle activity was recorded in two conditions (during resting mandibular position and maximum voluntary clenching) before and after the application of the CT to the MTrPs in MM. After the CT application, a significant decrease in resting activity (3.09 μV vs. 2.37 μV, p = 0.006) and a significant increase in clenching activity (110.20 μV vs. 139.06 μV, p = 0.014) within the MM muscles were observed in the study group, which was not observed within TA muscles. Controls showed significantly higher active MMO values compared to the study group before CT (50.42 mm vs. 46.31 mm, p = 0.024). The differences between the study group after CT and controls, as well as among the study group before and after CT did not reach the assumed level of significance in terms of active MMO. The compression technique appears to be effective in the improvement of the active maximal mouth opening and gives significant acute effects on bioelectric masticatory muscle activity. Therefore, CT seems to be effective in MTrPs rehabilitation within the stomatognathic system.

The pathophysiological nature of sarcomeres in trigger points in patients with myofascial pain syndrome: A preliminary study

Background

Myofascial pain syndrome (MPS) has a high global prevalence and is associated with myofascial trigger points (MTrPs) in taut bands or nodules. Little is known about the aetiology. The current study assessed the pathophysiological characteristics of MTrPs in MPS patients.

Methods

Biopsies of the trapezius muscle were collected from the MTrPs of MPS patients (MTrP group; n = 29) and from healthy controls (control group; n = 24), and their morphologies were analysed via haematoxylin‐eosin (H&E) and Masson staining. A protein microarray was used to detect the receptor tyrosine kinase (RTK) family proteins. mRNA and long non‐coding RNA (lncRNA) sequencing and analysis were conducted, and immunohistochemistry and Western blotting were used to examine the expression of EphB and Rho family proteins.

Results

Abnormally contracted sarcomeres showed enlarged, round fibres without inflammation or fibrosis. An lncRNA‐mRNA network analysis revealed activation of muscle contraction signalling pathways in MTrP regions. Among RTK family proteins, 15 exhibited increased phosphorylation, and two exhibited decreased phosphorylation in the MTrP regions relative to control levels. In particular, EphB1/EphB2 phosphorylation was increased on the muscle cell membranes of abnormal sarcomeres. RhoA and Rac1, but not cell division control protein 42 (Cdc42), were activated in the abnormal sarcomeres.

Conclusions

EphB1/EphB2 and RhoA/Rac1 might play roles in the aetiology of abnormally contracted sarcomeres in MTrPs without inflammatory cell infiltration and fibrotic adhesion.

Significance

Contracted sarcomeres were found in MTrP regions, which is consistent with the MTrP formation hypothesis. EphB1/EphB2 and RhoA/Rac1 might play roles in the sarcomere contractile sites of MTrPs, which may be promising therapeutic targets.

Effects of Stellate Ganglion Blockade on Muscle Blood Flow During Hypercapnia

This study investigated the effects of a unilateral stellate ganglion block (SGB) on ipsilateral and contralateral masseter muscle blood flow during permissive hypercapnia. Eight male Japanese white rabbits were anesthetized with isoflurane. Observed variables included heart rate (HR), blood pressure (BP), left common carotid artery blood flow (LCBF), left and right masseter muscle tissue blood flow (LMBF and RMBF), and left femoral quadriceps muscle tissue blood flow (LQBF). Variable measurements were taken at a baseline end-tidal carbon dioxide tension (EtCO2) of 40 mm Hg and repeated at an elevated EtCO2 of 60 mm Hg prior to and after administration of a left SGB. HR decreased, while systolic BP was elevated during hypercapnia and after the SGB. LCBF increased during hypercapnia and after the SGB. LMBF and RMBF decreased to 75% and LQBF decreased to 60% of their respective baseline values during hypercapnia. After the SGB, LMBF was restored, reapproximating its baseline, but RMBF and LQBF further decreased to 55 and 45% of their respective baseline values. In conclusion, unilateral SGB restored the ipsilateral masseter muscle blood flow that had been reduced during hypercapnia. In contrast, the SGB exacerbated the hypercapnia-induced reduction in blood flows in the contralateral masseter muscle and the femoral quadriceps muscle.

Depression of Mitochondrial Function in the Rat Skeletal Muscle Model of Myofascial Pain Syndrome Is Through Down-Regulation of the AMPK-PGC-1α-SIRT3 Axis

Purpose

The causative mechanisms triggering myofascial pain syndrome (MPS) are still in debate. It is becoming evident that mitochondrial dysfunction may regulate pathways controlling MPS. The aim of this study was to investigate whether AMPK-PGC-1α-SIRT3 axis is associated with depression of mitochondrial function in the rat MPS model.

Methods

A total of 32 Sprague-Dawley rats were randomly divided into control group and experimental group. The expression level of mRNA and protein of gastrocnemius medialis (GM) was analyzed by Western blot and RT-PCR. The histopathological findings were investigated through electron microscopes in GM of all groups.

Results

Our results showed that MPS induces continuous depression of mitochondrial biogenesis and function via down-regulation of PGC-1α-SIRT3 axis accompanying with ATP fuel crisis as compared to control group. However, the expression level of SIRT3 mRNA did not change. Additionally, a correlated reduction of the mRNA and protein expression level of NRF-1 and TFAM, known as the downstream target of PGC-1α, suggesting further transcription of nuclear genes encoding mitochondria functional proteins for promoting mitochondria proliferation, oxidative phosphorylation and energy production is continuously depressed. Furthermore, phosphorylation extent of AMPK is also declined following MPS, and it is negatively correlated with reduction of ATP generation, suggesting that the complex network involves different inhibition in transcription, post-translational modification and a plethora of other effectors that mediate the inhibition roles.

Conclusion

We here suggested that the down-regulation in AMPK-PGC-1α-SIRT3 axis network may be the basis for the association between mitochondrial dysfunction and MPS, where a vicious circle further aggravates the disease symptoms with ongoing ATP energy crisis.

Does the type of foam roller influence the recovery rate, thermal response and DOMS prevention?

PURPOSE

Supporting post-exercise recovery requires choosing not only the right treatment but also the equipment, in which the impact is not always clear. The study aimed to determine the effect of foam rolling on the rate of lactate removal and DOMS prevention and whether the type of foam roller is effective in the context of post-exercise recovery.

METHODS

This randomized trial enrolled 33 active healthy males divided into three groups of eleven individuals: foam rolling with a smooth (STH) or grid roller (GRID) or passive recovery (PAS). All the participants performed full squat jumps for one minute. Examination took place at rest (thermal imaging of skin temperature-[Tsk] and blood lactate-[LA]), immediately following exercise (Tsk & LA), immediately after recovery treatment (Tsk) and after 30 minutes of rest (Tsk & LA). Their pain levels were assessed using the Visual Analog Scale (VAS) 24, 48, 72, and 96 hours after exercise.

RESULTS

The magnitude of lactate decrease depended on the type of recovery used. In the PAS group, the decrease in lactate concentration by 2.65 mmol/L following a half-hour rest was significantly lower than that in the other groups (STH vs. PAS p = 0.042 / GRID vs. PAS p = 0.025). For thermal responses, significant differences between both experimental groups were noted only 30 minutes after exercise. A significant decrease in pain in the STH group occurred between 48 and 96 hours, while the GRID group showed a systematic significant decrease in VAS values in subsequent measurements. Changes in VAS values in subsequent measurements in the PAS group were not statistically significant (p>0.05).

CONCLUSIONS

Foam rolling seems to be effective for enhancing lactate clearance and counteracting DOMS, but the type of foam roller does not seem to influence the recovery rate.

Percutaneous Application of Galvanic Current in Rodents Reverses Signs of Myofascial Trigger Points

An increase in the spontaneous release of acetylcholine (ACh) at the motor endplate is directly related to the generation of myofascial trigger points (MTrPs). In this study, percutaneous electric fields were applied to an animal model of MTrPs with high levels of spontaneous ACh release. All experiments were performed on Swiss mice and Sprague Dawley rats. For evaluating the spontaneous neurotransmission, intracellular recordings were performed, and the frequency of miniature endplate potentials was evaluated. Electromyographic recordings were also conducted to evaluate the endplate noise. Finally, the number and strength of local twitch responses (LTR) were evaluated using ultrasound recordings. The protocols used for the electric currents were 0.4 mA for five seconds and four repetitions (protocol 1), 1.5 mA for five seconds and three repetitions (protocol 2), and 3 mA for three seconds and three repetitions (protocol 3). After a subcutaneous injection of neostigmine (NTG), a great increase was observed in the frequency of mEPPs, together with an elevated endplate noise. Protocols 2 and 3 were the most effective. Protocol 3 could completely reverse the action of NTG at both three hours and 24 hours, respectively. The application of percutaneous currents produced both an increase in the number (144%) and in the speed (230% faster) of LTR compared with dry needling. In conclusion, higher doses of electrical current are more effective for decreasing MTrPs findings in an animal model.

Myofascial Trigger Points Therapy Modifies Thermal Map of Gluteal Region

Background

Thermal imaging may be effectively used in musculoskeletal system diagnostics and therapy evaluation; thus, it may be successfully applied in myofascial trigger points assessment.

Objective

Investigation of thermal pattern changes after myofascial trigger points progressive compression therapy in healthy males and females.

Methods

The study included 30 healthy people (15 females and 15 males) with age range 19–34 years (mean age: 23.1 ± 4.21). Thermograms of myofascial trigger points were taken pre- and posttherapy and consecutively in the 15^th and 30^th minutes. Pain reproducible by palpation intensity was assessed with numeric rating scale.

Results

Progressive compression therapy leads to myofascial trigger points temperature (p=0.02) and surface (p=0.02) and surface (p=0.02) and surface (p=0.02) and surface (

Conclusions

The study indicates that myofascial trigger points reaction to applied therapy spreads in time and space and depends on participants' sex.

The effect of the twin block compared with trigger point injections in patients with masticatory myofascial pain: a pilot study

OBJECTIVE

The twin block, a novel nerve block that blocks the deep temporal and masseteric branches of the trigeminal nerve, has been shown to be effective in the short-term management of masticatory myofascial pain. However, little is known about its effectiveness in long-term management. The objective of this study was to assess the efficacy of the twin block in comparison with trigger point injections for the treatment of masticatory myofascial pain.

STUDY DESIGN

Forty-eight patients age 18 to 89 years were randomly assigned to the twin block group (n = 23) or the trigger point injection group (n = 25). The final analysis was based on a total number of 40 patients.

RESULTS

Mean numerical pain intensity at baseline was 6.54 ± 1.90 for the trigger point injection group and 6.47 ± 2.23 for the twin block group. At the 6th month visit, it was 1.85 ± 1.85 for the trigger point injection group and 1.85 ± 1.94 for the twin block group. There were no statistically significant differences in pain intensity between the 2 groups at baseline (P = .64) and at the 6th month follow-up (P = .45).

CONCLUSIONS

The twin block is effective in the long-term management of masticatory myofascial pain compared with trigger point injections.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03870191.

Effect of transcutaneous electrical acupuncture point stimulation on expression of p-JNK in the dorsal root ganglion in a rat model of myofascial pain syndrome

BACKGROUND

Acupuncture has been used to treat myofascial pain syndrome (MPS) for 2000 years in China, but its mechanisms are still not entirely clear. In the present study, we explored the effects of transcutaneous electrical acupuncture point stimulation (TEAS) at an Ashi acupuncture point on expression of phosphorylated c-Jun N-terminal kinase (p-JNK) in the dorsal root ganglion (DRG) using a rat model of MPS.

METHODS

32 rats were divided into four groups: normal, MPS, MPS+TEAS and MPS+sham- TEAS. MPS was produced by a blunt strike to the left vastus medialis combined with eccentric exercise for 8 weeks. Rats in the MPS+TEAS group received TEAS (6-9 mA, 2 Hz, 30 min) treatment at the Ashi acupuncture point for 2 weeks; rats in the MPS+sham -TEAS group had the same electrodes applied but received no stimulation. Paw withdrawal thermal latency (PWTL) was studied at baseline and on days 3, 7, 11 and 15 after treatment. Haematoxylin and eosin staining was used to examine for morphological changes in the left vastus medialis muscles; expression of p-JNK in the L3-L5 DRG was determined by immunofluorescence staining and western blotting after treatment.

RESULTS

Compared with the normal group, PWTL decreased significantly (P<0.01) and the expression of p-JNK in the DRG increased in the MPS and MPS-sham-TEAS groups (P<0.01); compared with the MPS group, PWTL was increased significantly (P<0.01) and expression of p-JNK in the DRG was decreased in the MPS+TEAS group. However, when compared with the normal group, PWTL did not recover to baseline and expression of p-JNK was still higher.

CONCLUSION

TEAS treatment may produce an analgesic effect, probably by inhibiting the expression of p-JNK in the DRG of rats with MPS.

Changes in salivary oxidative status, salivary cortisol, and clinical symptoms in female patients with temporomandibular disorders during occlusal splint therapy: a 3-month follow up

Background

Differences in the expression of oxidative stress (OS) markers between female patients with temporomandibular disorders (TMD) and healthy individuals indicate that OS plays a role in the pathogenesis of TMD. Because chronic exposure to stress generates oxidative damage during continuous stimulation of the hypothalamic-pituitary-adrenal axis, we expected that higher levels of cortisol might be associated with higher oxidative damage. Our aim was to test the association between OS markers, stress perception, and salivary cortisol (SC) in chronic, female TMD patients. We tracked changes in OS markers and SC during occlusal splint therapy in order to evaluate the influence of treatment on oxidative status. We hypothesized that the effects of TMD therapy would differ among individuals depending on the source and intensity of pain.

Methods

Sixteen female patients were recruited, and 12 finished the study. Clinical assessment and saliva sampling were performed at the baseline and follow-up appointments. Repeated measures analysis of variance and Pearson’s correlation were used for analyzing the data.

Results

After 3 months, a significant reduction in afternoon total antioxidant capacity (TAC) was observed (p < 0.05). A significant reduction in afternoon malondialdehyde (MDA) (p = 0.021) and a decrease in afternoon MDA to superoxide dismutase ratios (p = 0.017) were present in high-intensity pain patients. At baseline, higher levels of perceived stress were significantly associated with higher morning cortisol (ρ = 0.67). At the end of the therapy,  reduced  perceived stress was positively correlated with morning SC changes when considering all TMD patients, but the association between perceived stress with OS markers was present only in myofascial pain (MP) group. The effect of treatment on the self-perceived quality of life was more pronounced in female MP patients while the reduction of spontaneous pain was significantly greater in high-intensity pain patients.

Conclusion

Our data indicate that occlusal splint therapy in female TMD patients contributes to increasing their capacity to remove free radicals. The question remains whether or not TAC decreases in this process as a result of avoiding unnecessary processes, once the increase in antioxidants effectively compensates for OS. The intensity and the source of pain should be considered important factors in future investigations evaluating salivary OS markers and their association with perceived stress and SC in TMD patients.

Trial registration

ClinicalTrials.gov NCT03029494. Registered on 2017-01-19.

Assessment of predisposing factors in myofascial pain syndrome and the analgesic effect of trigger point injections - A primary therapeutic interventional clinical trial

Background and Aims

Myofascial pain syndrome (MPS) is a common cause of chronic musculoskeletal pain, characterised by myofascial trigger points (TPs). TP injection is an established technique for management of MPS. In this study, we analysed the efficacy of myofascial TP injection of lignocaine and the influencing biomechanical factors on MPS.

Methods

After obtaining ethical committee approval, we included the first 100 adult patients of MPS with failed physical therapy aged above 18 years, and with TPs in the trapezius, infraspinatus, and/or the levator scapulae muscles and Visual analog scale (VAS) >4. TP injection of 2% (2 ml) lignocaine was performed. Visual analogue scale (VAS) scores were recorded immediately and after 1 month. Number of repeat TP injections and use of oral analgesic in one month was noted. Results were analysed with the analysis of variance test.

Results

The mean VAS reduced significantly both immediately and 1 month after therapeutic injections (8.57 ± 0.77, 2.67 ± 1.43 and 2.82 ± 1.4, respectively, P < 0.01). Keeping the palm below the head during sleep was the major contributing factor for myofascial TP, followed by slanting the neck to use mobile phones. Repeat TP injection was used in 4% of cases.

Conclusion

TP injection of 2 ml of 2% lignocaine along with correction of predisposing biomechanical factors provided significant pain relief for MPS in patients with failed physical therapy without any side effects.

Evaluation of mitochondrial function in chronic myofascial trigger points - a prospective cohort pilot study using high-resolution respirometry

Background

Myofascial trigger points (MTrPs) are hyperirritable areas in the fascia of the affected muscle, possibly related to mitochondrial impairment. They can result in pain and hypoxic areas within the muscle. This pilot study established a minimally invasive biopsy technique to obtain high-quality MTrP tissue samples to evaluate mitochondrial function via high-resolution respirometry. Secondary objectives included the feasibility and safety of the biopsy procedure.

Methods

Twenty healthy males participated in this study, 10 with a diagnosis of myofascial pain in the musculus (m.) trapezius MTrP (TTP group) and 10 with a diagnosis of myofascial pain in the m. gluteus medius (GTP group). Each participant had 2 muscle biopsies taken in one session. The affected muscle was biopsied followed by a biopsy from the m. vastus lateralis to be used as a control. Measurements of oxygen consumption were carried out using high-resolution respirometry.

Results

Mitochondrial respiration was highest in the GTP group compared to the TTP group and the control muscle whereas no differences were observed between the GTP and the control muscle. When normalizing respiration to an internal reference state, there were no differences between muscle groups. None of the participants had hematomas or reported surgical complications. Patient-reported pain was minimal for all 3 groups. All participants reported a low procedural burden.

Conclusions

This pilot study used a safe and minimally invasive technique for obtaining biopsies from MTrPs suitable for high-resolution respirometry analysis of mitochondrial function. The results suggest that there are no qualitative differences in mitochondrial function of MTrPs of the trapezius and gluteus medius muscles compared to the vastus lateralis control muscle, implying that alterations of mitochondrial function do not appear to have a role in the development of MTrPs.

Trial registration

Registered as No. 20131128–850 at the Coordinating Center for Clinical Studies of the Medical University of Innsbruck, trial registration date: 28th November 2013 and retrospectively registered on 11th of October 2018 at ClinicalTrials.gov with the ID NCT03704311.

The interrater reliability of a pain mechanisms-based classification for patients with nonspecific neck pain

OBJECTIVE

To examine the interrater reliability and agreement of a pain mechanisms-based classification for patients with nonspecific neck pain (NSNP).

METHODS

Design - Observational, cross-sectional reliability study with a simultaneous examiner design.

SETTING

University hospital-based outpatient physical therapy clinic.

PARTICIPANTS

A random sample of 48 patients, aged between 18 and 75 years old, with a primary complaint of neck pain was included.

INTERVENTIONS

Subjects underwent a standardized subjective and clinical examination, performed by 1 experienced physical therapist. Two assessors independently classified the participants' NSNP on 3 main outcome measures.

MAIN OUTCOME MEASURES

The Cohen kappa, percent agreement, and 95% confidence intervals (CIs) were calculated to determine the interrater reliability for (1) the predominant pain mechanism; (2) the predominant pain pattern; and (3) the predominant dysfunction pattern (DP).

RESULTS

There was almost perfect agreement between the 2 physical therapists' judgements on the predominant pain mechanism, kappa=.84 (95% CI, .65-1.00), p<.001. There was substantial agreement between the raters' judgements on the predominant pain pattern and predominant DP with respectively kappa=.61 (95% CI, .42-.80); and kappa=.62 (95% CI, .44-.79), p<.001.

CONCLUSION(S)

The proposed classification exhibits substantial to almost perfect interrater reliability. Further validity testing in larger neck pain populations is required before the information is used in clinical settings.

CLINICAL TRIAL REGISTRATION NUMBER

NCT03147508 (https://clinicaltrials.gov/ct2/show/NCT03147508).

Dry needling versus trigger point compression of the upper trapezius: a randomized clinical trial with two-week and three-month follow-up

Objectives: The purpose of this randomized controlled trial was to investigate the long-term clinical effect of dry needling with two-week and three-month follow up, on individuals with myofascial trigger points in the upper trapezius muscle. Methods: A sample of convenience (33 individuals) with a trigger point in the upper trapezius muscle, participated in this study. The individuals were randomly assigned to two groups: trigger point compression (N = 17) or dry needling (N = 16). Pain intensity, neck disability, and disability of the arm, hand, and shoulder (DASH) were assessed before treatment, after treatment sessions, and at two-week and three-month follow ups. Results: The result of repeated measures ANOVA showed significant group-measurement interaction effect for VAS (p = .02). No significant interaction was found for NPQ and DASH (p > .05). The main effect of measurements for VAS, NPQ, and DASH were statistically significant (p < .0001). The results showed a significant change in pain intensity, neck disability, and DASH after treatment sessions, after two weeks and three months when compared with before treatment scores in both groups.  There was no significant difference in the tested variables after two-week or three-month as compared to after treatment sessions between the two groups. However, pain intensity after treatment sessions was significantly different between the two groups (p = .02). Discussion: Dry needling and trigger point compression in individuals with myofascial trigger point in the upper trapezius muscle can lead to three-month improvement in pain intensity and disability.

Experimental myofascial trigger point creation in rodents

Myofascial pain syndrome is one of the most common forms of muscle pain. In this syndrome, pain is originated by the so-called trigger points, which consists of a set of palpable contraction knots in the muscle. It has been proposed that a high, spontaneous neurotransmission may be involved in the generation of these contraction knots. To confirm this hypothesis, we exposed mouse muscles to an anticholinesterasic agent to increase the neurotransmision in the synaptic cleft in two different conditions, in vivo and ex vivo experiments. Using intracellular recordings, a sharp increase in the spontaneous neurotransmission in the levator auris longus muscle and a lower increase in the diaphragm muscle could be seen. Likewise, electromyography recordings reveal an elevated endplate noise in gastrocnemius muscle of treated animals. These changes are associated with structural changes such as abundant neuromuscular contracted zones observed by rhodaminated α-bungarotoxin and the presence of abundant glycosaminoglycans around the contraction knots, as shown by Alcian PAS staining. In a second set of experiments, we aimed at demonstrating that the increases in the neurotransmission reproduced most of the clinical signs associated to a trigger point. We exposed rats to the anticholinesterase agent neostigmine, and 30 min afterward we observed the presence of palpable taut bands, the echocardiographic presence of contraction knots, and local twitch responses upon needle stimulation. In summary, we demonstrated that increased neurotransmission induced trigger points in both rats and mice, as evidenced by glycosaminoglycans around the contraction zones as a novel hallmark of this pathology. NEW & NOTEWORTHY In rodents, when neostigmine was injected subcutaneously, the neuromuscular neurotransmission increased, and several changes can be observed: an elevated endplate noise compared with normal endplate noise, as evidenced by electromyographyc recording; many muscular fibers with contraction knots (narrower sarcomeres and locally thickened muscle fiber) surrounded by infiltration of connective tissue like glycosaminoglycans molecules; and palpable taut bands and local twitch responses upon needle stimulation. Several of these signs are also observed in humans with muscle pain.

Early Intervention and Nonpharmacological Therapy of Myopia in Young Adults

Myopia is a condition of the eye where parallel rays focus in front of, instead of on, the retina, which results in excessive refractive power of the cornea or the lens or eyeball elongation. Studies carried out in recent years show that the etiology of myopia is complex with genetic and environmental factors playing a role. Refraction defects decrease the quality of vision, while progressing myopia can lead to partial loss of vision, which can be particularly dramatic in young adults. Therefore, it is so crucial to take appropriate actions aimed at preventing myopia progression. This is a review of nonpharmacological therapeutic possibilities of refraction defect prevention in young adults, with special regard to myofascial therapy, osteopathy, and massage of acupuncture points surrounding the eye.