Myofascial pain - A major player in musculoskeletal pain.

Myofascial pain is a soft tissue pain syndrome with local and referred musculoskeletal pain arising from trigger points. Myofascial pain and myofascial pain syndromes are among some of the most common acute and chronic pain conditions. Myofascial pain can exist independently of other pain generators or can coexist with or is secondary to other acute and chronic painful musculoskeletal conditions. Myofascial pain is most effectively treated with a multimodal treatment plan including injection therapy (known as trigger point injections, physical therapy, postural or ergonomic correction, and treatment of underlying musculoskeletal pain generators. The objectives of this review are to outline the prevalence of myofascial pain, describe the known pathophysiology of myofascial pain and trigger points, discuss the clinical presentation of myofascial pain, and present evidence-based best practices for pharmacologic, non-pharmacologic, and interventional treatments for myofascial pain.

Effect of Sympathetic Blockade on Spontaneous Discharge and the H-Reflex at Myofascial Trigger Points in Rats.

Purpose: Myofascial trigger points (MTrPs) are the main cause of myofascial pain syndrome (MPS), and patients with MPS also have symptoms of sympathetic abnormalities. Consequently, this study aimed to investigate the potential relationship between MTrPs and sympathetic nerves. Materials and Methods: Twenty-four seven-week-old male rats were randomly divided into four groups (six rats every group). Groups I and II were kept in normal condition (n=12), and groups III and IV underwent MTrPs modelling (n=12). After successful MTrPs modelling, differences in sympathetic outcomes between the MTrPs groups (III and IV) and non-MTrPs groups (I and II) were observed. Sympathetic blockade was then applied to groups III and I (n=12). Data were collected on peak inversion spontaneous potentials (PISPs) and the H-reflex-evoked electromyography during spontaneous discharge at the MTrPs before and after sympathetic blockade. Results: Systolic blood pressure, diastolic blood pressure, mean arterial pressure, and heart rate were significantly higher in the MTrPs group than in the non-MTrPs group (P<0.05). Compared with group I, group III had the PISPs potential lower wave amplitude, shorter duration and amplitude-to-duration ratio, and lower H latency and latency difference H-M (P<0.05). Compared with group IV, group III had the PISPs potential lower wave amplitude, duration, amplitude-to-duration ratio, M-wave latency, H maximum wave amplitude, and maximal wave amplitude ratio H/M (P<0.05). The changes before and after sympathetic blockade in the MTrPs group were significant, and the amplitude, duration, and amplitude-to-duration ratio of the PISPs potentials were lower after the blockade (P<0.05). Conclusion: MTrPs and sympathetic nerves interact with each other forming a specific relationship. MTrPs sensitize sympathetic nerves, and sympathetic nerve abnormalities affect local muscle myoelectric hyperactivity, leading to MTrPs. This finding is instructive for the clinical management of sympathetic disorders.

Association between smartphone addiction and myofascial trigger points.

BACKGROUND: The purpose of this study was to clarify the relationship between smartphone addiction and miyafascial trigger points in university students. METHODS: A cross-sectional study of university students was conducted for the purpose of this study. The participants were assessed based on age, gender, dominant side, the amount of time they spent on their smartphones, the purpose of their use, and their posture. The Smartphone Addiction Scale Short Form (SAS-SF) was used to determine addictes and non-addicts. The cut-off value of SAS-SF is 31 and above for male and 33 and above for female. RESULTS: There were 136 participants in the study. The posture score for addicts and non-addicts ones was not significantly different (p > 0,05), but the number of trigger points, maximal bending posture and trigger points in the right levator scapula and right cervical erector muscles were significantly higher in the smartphone addict participants (p < 0,05). CONCLUSIONS: Smartphone addiction in university students is associated with postural changes and trigger points in the bilateral levator scapula and right cervical erector muscles. Public health programs should be developed to raise awareness about smartphone addiction, encourage screen breaks, and emphasize physical activity and exercise regularly.

Effect of Mirror Therapy on Post-Needling Pain Following Deep Dry Needling of Myofascial Trigger Point in Lateral Elbow Pain: Prospective Controlled Pilot Trial.

Background: This prospective randomized, controlled pilot trial to explore the immediate effect of adding Mirror Visual Feedback Therapy on pain sensitivity and motor performance among subjects suffering from post-needling pain diagnosed as Lateral Elbow Pain. Methods: A total of 49 participants (23 female, 26 male) were enrolled and randomly allocated to either the experimental group, which received Deep Dry Needling in the m. Brachioradialis, Ischemic Compression, Cold Spray, Stretching, and Mirror Visual Feedback Therapy (n = 25), or a control group without Mirror Visual Feedback Therapy (n = 24). Pre- and post-treatment evaluations included assessments of post-needling pain intensity, pressure pain threshold, two-point discrimination threshold, and maximum hand grip strength. Results: Intergroup analysis revealed a statistically significant reduction in post-needling pain intensity favoring the experimental group (U = 188.00, p = 0.034). Additionally, intragroup analysis showed significant improvements in post-needling pain intensity (MD = 0.400, SEM = 0.271, W = 137.00, p = 0.047) and pressure pain threshold (MD = 0.148 Kg/cm2, SEM = 0.038, W = 262.00, p < 0.001) within the experimental group following the intervention. Conclusions: These findings suggest a potential benefit of integrating Mirror Visual Feedback Therapy into treatment protocols for individuals with Lateral Elbow Pain experiencing post-needling discomfort. Further research is necessary to fully elucidate the clinical implications of these findings.

Effects of transcutaneous radiofrequency diathermy versus ultrasound on latent myofascial trigger points in the upper trapezius: A randomized crossover trial.

BACKGROUND: Currently, the use of radiofrequency diathermy for the treatment of neck pain is booming. OBJECTIVE: This study aimed to evaluate the clinical efficacy of Digital Capacitive Diathermy (DCD®) on stiffness, pain, cervical range of motion, and cervical disability and to compare it with ultrasound (US) in patients with latent myofascial trigger point (MTrP) in the upper trapezius. METHODS: Nineteen participants with latent MTrPs in the upper trapezius were included in the assessor-masked, randomized, clinical crossover trial. Subjects were exposed to both interventions: US and DCD® and treatment effectiveness was measured by myotonometric variables, pressure pain threshold (PPT), visual analog scale (VAS), cervical side-bending flexion ranges, and the neck disability index scale (NDI). RESULTS: There were no significant differences between US and DCD® interventions regarding changes in outcome measures. The US group achieved a statistically significant difference of 2.16 to 1.13 points (p= 0.005; r= 0.646) for the VAS. The DCD® intervention showed a statistically significant improvement of 1.11 points for the NDI at 1-week following intervention (95% CI 0.14-2.07; p= 0.27; d= 0.217). CONCLUSION: Our findings suggest that DCD® and US can both be considered effective modalities for the treatment of latent MTrPs, having a longer duration of action with DCD® therapy.

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

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

Efficacy of trigger point injection therapy in noncardiac chest pain: A randomized controlled trial.

Objectives: This study aimed to compare the effects of trigger point injections and stretching exercises in patients with noncardiac chest pain (NCCP) associated with myofascial pain syndrome. Patients and methods: This prospective randomized controlled trial included 50 patients with noncardiac chest pain and trigger points in the pectoralis muscles between October 2019 and June 2020. The patients were randomly assigned to receive trigger point injections into the pectoralis muscles and exercise (n=25; 15 males, 10 females; mean age: 42.8±9.2 years; range, 25 to 57 years) or only perform exercise (n=25; 11 males, 14 females; mean age: 41.8±11.2 years; range, 18 to 60 years). The primary outcome was pain intensity at the first month and three months after the first treatment session, measured using the Visual Analog Scale from 0 to 100. The secondary outcome was the Nottingham Health Profile score. Results: Treatment with stretching exercises and trigger point injection resulted in significant pain reduction compared to stretching exercises alone, and the reduction was persistent at the three-month follow-up (p<0.001). A between-group comparison showed no significant difference in the Nottingham Health Profile (p=0.522). Complications related to the procedure or severe adverse events attributable to treatment were not reported. Conclusion: Trigger point injection combined with stretching exercises is an efficient treatment for noncardiac chest pain related to myofascial pain syndrome compared to exercise treatment alone.

Comparing Myofascial Pain Syndrome Treatment with Dry Needling Versus Extracorporeal Shock Wave Therapy for Plantar Fasciitis on Pain and Function of the Heel.

The aim of this study was to compare the effects of dry needling (DN) and extracorporeal shock wave therapy (ESWT) in the treatment of plantar fasciitis (PF). The study included 55 patients with PF. The patients were randomly divided into 2 groups. The DN group applied 3 sessions of DN to the myofascial trigger points in the lower limb muscles. The ESWT group applied 3 sessions of ESWT to the plantar fascia. For clinical evaluation, we used a visual analog scale (VAS) (first step, rest, activity) and Foot Function Index (FFI) (pain, disability, activity). Assessments were done baseline, post-treatment first week, and fourth week. Maximum pain-free standing time (Max PfST) and maximum pain-free walking distance (Max PfWD) were recorded at baseline and post-treatment fourth week. In this study, we found significant improvement in VAS, FFI, Max PfST, and Max PfWD in both groups (p < .01). VAS-activity baseline-forth week change was significantly superior in the DN group compared to the ESWT group (p = .023). FFI-disability baseline-fourth week change was significantly superior in the DN group compared to the ESWT group (p = .048). There was no significant difference in other treatment-related changes between the groups (p > .05). However, VAS-rest baseline-fourth week change and FFI-pain baseline-fourth week change trended towards statistical significance between groups ((p = .056), (p = .052) respectively). This study showed that DN may be a good alternative treatment for patients with PF, with effects similar to or even superior to ESWT.

Comparison of Dry Needling and Cold-Spray-Stretching Treatments by Ultrasonography and Electrophysiology: Prospective, Randomized Controlled Trial.

OBJECTIVES: To compare the efficacy of dry needling (DN) and cold-spray-stretching treatments using surface electromyography (sEMG) and ultrasound (US) in the treatment of patients with myofascial pain syndrome (MPS) with active trigger point (ATrP) in the upper trapezius muscle. METHODS: This prospective randomized single-blind study included 60 MPS patients aged 18-65 years who have ATrP in the upper trapezius muscle. Patients were randomized into two treatment groups as DN and cold spray stretching. Both treatment groups received 1 treatment per week and totally 3 sessions. Evaluation parameters were pain level assessed by Numeric Rating Scale and algometer, neck range of motion angles, neck disability index (NDI). The effects of the treatments on ATrP were evaluated by sEMG and US histogram. All parameters were evaluated at the beginning of the treatment and at the end. Algometer and sEMG were performed also before and after the first and third sessions. RESULTS: There was no significant difference between the two groups regarding demographic data. The mean age of the participants was 39.7 ± 11.6 years. Fifty-one patients were female. Significant improvement in terms of pain level, functionality, sEMG, and US histogram were achieved in both groups (P < .05). When comparing the two groups, algometer scores and the NDI score were statistically higher in the cold-spray-stretching group than in the DN group (P < .008 and P < .028, respectively). CONCLUSION: Both treatment options should be preferred. The efficacy of both treatments was observed via sEMG and US histograms.

Extracorporeal shockwave therapy of the perineum for male patients with chronic pelvic pain syndrome: a pilot study.

Background: Chronic pelvic pain syndrome (CPPS) is a complex condition that is often difficult to treat and may sometimes require a multidisciplinary team. Among the wide array of treatment options is extracorporeal shockwave therapy (ESWT). However, its role in CPPS remains controversial. The purpose of our study is to assess the efficacy and safety of ESWT of the perineum in male patients with CPPS. Methods: Fourteen patients aged between 21 and 85 years were recruited in this single-center, single-arm prospective trial from October 2018 to October 2020. ESWT was delivered to the perineum weekly for up to 8 weeks. Assessment was done via International Index for Erectile Function, International Prostate Symptom Score, King's Health Questionnaire, National Institutes of Health - Chronic Prostatitis Symptom Index, Visual Analogue Scale, Analgesic Questionnaire, and UPOINT (urinary symptoms [U], psychosocial dysfunction [P], organ-specific symptoms [O], infection-related symptoms [I], neurological/systemic conditions [N], tenderness of skeletal muscles [T]) phenotype system. The parameters are assessed before the start and end of treatment as well as at regular time points on follow-up appointments up to 20 weeks. Results: Thirteen patients completed the study. There was improvement in the Visual Analogue Scale pain score, Tenderness domain on UPOINT, King's Health Questionnaire, and National Institutes of Health - Chronic Prostatitis Symptom Index scores. In terms of erectile function, improvement in the erectile function domain of International Index for Erectile Function was observed. There was also significant improvement in lower urinary tract symptoms assessed on International Prostate Symptom Score. There were no adverse events reported post treatment and during the follow-up period. Conclusions: ESWT improved pain and quality of life of male patients with CPPS. It can be a safe and effective treatment modality in the armamentarium of CPPS.

Therapeutic effects of dry needling on lateral epicondylitis: An updated systematic review and meta-analysis.

OBJECTIVE: To investigate the therapeutic effects of dry needling on lateral epicondylitis and identify a relatively more effective needling technique. DATA SOURCES: English databases (Pubmed, Web of Science, Scopus, EBSCO, ScienceDirect, Taylor & Francis, ProQuest, Cochrane, Ovid, and Embase) and Chinese databases (China National Knowledge Infrastructure, Wanfang, and VIP) were searched. STUDY SELECTION: This study included randomized controlled trials for comparing the effectiveness of dry needling with other treatment methods for lateral epicondylitis. The primary outcome measures were pain intensity and elbow disability, while the secondary outcome measures included grip strength and upper limb function. DATA EXTRACTION: Data extraction was performed by two researchers who used the Cochrane risk of bias analysis tool and the Physiotherapy Evidence Database checklist to assess the risk of bias and methodological quality of the included studies. The Grading of Recommendations, Assessment, Development, and Evaluation approach was used to assess the quality of evidence. DATA SYNTHESIS: A total of 17 studies that involved 979 subjects were included in this research. Dry needling exhibited a significant advantage in improving pain intensity among patients with lateral epicondylitis within 1 week after treatment (mean difference [MD]=-0.95, 95% confidence interval [CI], -1.88 to -0.02). Within 1 week and in the follow-ups that exceeded 1 week, dry needling also demonstrated better improvement in elbow disability (<1 week: standardized mean difference [SMD]=-1.37, 95% CI, -1.88 to -0.86; ≥1 week: SMD=-1.32, 95% CI, -2.23 to -0.4) and grip strength (<1 week: SMD=0.27, 95% CI, 0.01 to 0.53; ≥1 week: SMD=0.45, 95% CI, 0.02 to 0.88). Trigger point dry needling with local twitch response exhibited more significant improvement in pain intensity within 1 week (MD=-1.09, 95% CI, -1.75 to -0.44). CONCLUSIONS: Dry needling demonstrates good therapeutic effects on pain intensity (within 1 week), function, and grip strength among patients with lateral epicondylitis. Local twitch response is necessary in treatment that targets trigger points.

Reliability of muscle stiffness measures in popliteus, medial and lateral gastrocnemius muscles by ultrasound shear wave elastography in participants with knee osteoarthritis accompanied by myofascial trigger points.

BACKGROUND: The objective of this investigation is to evaluate the consistency of intra-rater and inter-rater assessments utilizing ultrasound elastography to examine the muscle stiffness of the popliteus and gastrocnemius (medial and lateral heads) in patients with knee osteoarthritis accompanied by myofascial trigger points. METHODS: Thirty individuals with knee osteoarthritis accompanied by myofascial trigger points were assessed. Two examiners independently measured the muscle stiffness levels of the popliteus and gastrocnemius (medial and lateral heads) three times using ultrasound elastography in the first session. The second session was conducted one week later. RESULTS: In the initial test session, the mean shear modulus values for the popliteus and gastrocnemius (medial and lateral heads) muscles were measured as follows for tester 1 (12.75, 13.72, 14.13 kPa) and tester 2 (11.66, 12.81, 13.17 kPa). During the retest session, the previously measured variables by tester 1 and tester 2 yielded the following values: (12.61, 13.43, 14.26 kPa) and (11.62, 12.87, 13.30 kPa) respectively." Good to excellent intra-rater reliability (ICC = 0.912-0.986) and inter-rater reliability (ICC = 0.766-0.956) were reported for the shear moduli of the popliteus, medial and lateral gastrocnemius muscles. CONCLUSIONS: The assessment of muscle stiffness in the popliteus and gastrocnemius (medial and lateral heads) using ultrasound elastography is a reliable method in patients with knee osteoarthritis accompanied by myofascial trigger points.

The effect of simultaneous administration of occipital nerve block and cervical myofascial trigger point injection (MTrPI) on headache parameters in chronic migraine patients.

BACKGROUND AND AIM: Peripheral myofascial mechanisms have been identified as contributors to migraine pathophysiology. The specific comorbid relationship between migraine and cervical trigger points may exacerbate the occurrence and severity of migraine attacks. Trigger point injections (TPIs) are frequently employed to address headaches and alleviate migraine symptoms. The current study explores the impact of concurrent myofascial trigger point injection (MTrPI) and occipital nerve block (greater occipital nerve block [GONB] + lesser occipital nerve block [LONB]) on the severity of headaches and the number of migraine attacks in individuals with chronic migraine (CM) and cervical myofascial trigger points (MTrPs), with a comparison of occipital nerve block alone (GONB + LONB). During trigger point examination and injection, trapezius, levator scapulae, splenius capitis, temporalis, and sternocleidomastoid muscles were targeted. We planned the treatment based on whether they were in the muscle groups we determined, rather than the number of trigger points. MATERIALS AND METHOD: This study enrolled 62 individuals experiencing CM with bilateral headache and cervical MTrP who sought care at the Algology Unit within the Departments of Neurology and Physical Therapy and Rehabilitation at Siirt Training and Research Hospital between 2020 and 2022. The CM cohort was stratified into two groups: group 1 received trigger point injections (TrPI), while group 2 underwent concurrent bilateral occipital nerve block (GONB + LONB) and TrPI. Both groups underwent three treatment sessions with bupivacaine 0.5% (1 ml = 5 mg) in weeks 1, 2, and 4. Visual analog scale (VAS) was used to measure the patients' pain intensity. The evaluation included the assessment of the monthly migraine frequency and visual analog scale (VAS) p score for pain before treatment (BT) and after treatment (AT), conducted at baseline and during follow-up visits. Analysis of the data was conducted utilizing IBM SPSS Statistics for Windows version 28.0 software. RESULTS: Among patients diagnosed with CM and MTrPs, 32 individuals (51.6%) underwent GONB and LONB, while 30 patients (48.4%) received simultaneous GONB, LONB, and cervical MTrPI. Within the entire sample, 51 participants (82.3%) were female, and 11 (17.7%) were male, with a mean age of 32.81 ± 10.75 years. With an average age of 32.81 ± 10.75 years, there was no statistically significant variance between the two groups (p = 0.516). Of the total cohort, 45 individuals (72.6%) reported experiencing headaches persisting for 12 months or longer. Among CM patients, 80% had active trigger points, while 20% had latent trigger points. No statistically significant difference was observed between the groups concerning TrPs (p = 0.158), and the distribution of TrPs was homogenous across the two groups. In group 1, the median (min-max) monthly frequency of migraines reduced from 18.5 days (range: 15.0 to 25.0 days) before treatment to 12.0 days (range: 7.0 to 17.0 days) after treatment (p = 0.000). In group 2, the median monthly frequency of migraines reduced from 16.5 days (range: 15.0 to 22.0 days) before treatment to 4.0 days (range: 2.0 to 8.0 days) after treatment (p = 0.000). The median (min-max) VAS score in group 1 was 8.0 (range: 5.0 to 9.0) before treatment, 4.0 (range: 2.0 to 6.0) at week 1, and 5.0 (range: 4.0 to 8.0) at week 4 (p = 0.000). In group 2, the median VAS score was 7.0 (range: 5.0 to 9.0) before treatment, 0.0 (range: 0.0 to 0.3) at week 1, and 2.0 (range: 0.0 to 0.3) at week 4 (p = 0.000). There were significant distinctions between the groups in terms of both the monthly count of migraine days and the severity of headaches (p = 0.000). CONCLUSION: The combination of repeated MTrPIs and ONB proves more effective than ONB alone in managing patients with CM and cervical MTrP. In patients with CM, performing TrPs examination and adding treatments for this may contribute to the treatment. In cases where patients endure prolonged episodes of headache associated with chronic migraine, the inclusion of trigger point injections alongside peripheral nerve blocks may offer enhanced therapeutic benefits.

Assessment of the Performance of Ultrasonography for Detecting Myofascial Trigger Points.

Needle electromyogram (EMG) research has suggested that endplate noise (EPN) is a characteristic of myofascial trigger points (MTrPs). Although several studies have observed MTrPs through ultrasonography, whether they are hyperechoic or hypoechoic in ultrasound images is still controversial. Therefore, this study determined the echogenicity of MTrP ultrasonography. In stage 1, the MTrP of rat masseter muscle was identified through palpation and marked. Needle EMG was performed to detect the presence of EPN. When EPN was detected, ultrasound scans and indwelling needles were used to identify the nodule with a different grayscale relative to that of its surrounding tissue, and the echogenicity of the identified MTrP was determined. In stage 2, these steps were reversed. An ultrasound scan was performed to detect the nodule at the marked site, and an EMG needle was inserted into the nodule to detect EPN. There were 178 recordings in each stage, obtained from 45 rats. The stage 1 results indicate that the MTrPs in ultrasound images were hypoechoic with a 100% sensitivity of assessment. In stage 2, the accuracy and precision of MTrP detection through ultrasonography were 89.9% and 89.2%, respectively. The results indicate that ultrasonography produces highly accurate and precise MTrP detection results.

Autonomic Recalibration: A Promising Approach for Alleviating Myofascial Pain Explored in a Retrospective Case Series.

This retrospective case series introduces autonomic recalibration (AR) as a novel approach for alleviating chronic myofascial pain. The manuscript explores the rationale, theory, and practice of AR, which targets the autonomic nervous system (ANS) to restore homeostasis and reduce pain. The involvement of the ANS in pain modulation and the role of autonomic imbalance in chronic pain are discussed, emphasizing the potential benefits of addressing autonomic dysregulation through AR. The technique combines manual interventions and patient education, relying on neuroplastic adaptations. Three diverse case reports are presented to illustrate the effectiveness of AR in patients with different sources of pain. Each case presents a unique clinical scenario, including a nine-year-old male diagnosed with spondylolisthesis, a 68-year-old male with a history of abdominal surgeries, and a 56-year-old male with chronic low back pain following lumbar fusion surgery. In all cases, AR resulted in pain relief, improved sleep, and restoration of functional abilities. These findings support the potential of AR as an effective alternative approach for myofascial pain. Further research is warranted to validate these outcomes and investigate the underlying mechanisms of AR.

Clinical effectiveness of trigger point acupuncture on chronic neck and shoulder pain (katakori) with work productivity loss in office workers: a randomized clinical trial.

OBJECTIVES: To evaluate whether trigger point acupuncture (TrPA) is beneficial for office workers who have reduced job performance (presenteeism) due to chronic neck and shoulder pain (katakori). METHODS: A 4-week single-center randomized controlled trial was conducted on 20 eligible female office workers with chronic neck and shoulder pain of at least 3-month duration. The control group implemented only workplace-recommended presenteeism measures, whereas the intervention group received TrPA up to 4 times per month in addition to the presenteeism measures recommended by each workplace. The major outcome measure was the relative presenteeism score on the World Health Organization Health and Work Performance (WHO-HPQ). The secondary outcome measures were pain intensity (numerical rating scale), absolute presenteeism (WHO-HPQ), anxiety and depression (Hospital Anxiety and Depression Scale; HADS), catastrophic thoughts related to pain (Pain Catastrophizing Scale; PCS), and sleep (Athens Insomnia Scale; AIS). RESULTS: All 9 cases in the intervention group and 11 cases in the control group were analyzed. TrPA up to 4 times per month reduced the intensity of neck and shoulder pain by 20% (P < .01, d = 1.65) and improved labor productivity (relative presenteeism value) by 0.25 (P < .01, d = 1.33) compared with the control group over 1 month. No significant differences were observed between the 2 groups in terms of absolute presenteeism score, HADS, PCS, or AIS. CONCLUSIONS: These results suggest that regular intervention with TrPA may be effective in the relative presenteeism score before and after the intervention and the degree of neck and shoulder pain over 28 days compared with the control group.

Three Subtypes of Cutaneous Nerve Entrapment Syndrome: A Narrative Review.

Anterior, lateral, and posterior cutaneous nerve entrapment syndromes have been proposed as etiologies of trunk pain. However, while these syndromes are analogous, comprehensive reports contrasting the three subtypes are lacking. We therefore reviewed the literature on anterior, lateral, and posterior cutaneous nerve entrapment syndrome. We searched the PubMed and Cochrane Library databases twice for relevant articles published between March and September 2022. In addition to 16 letters, technical reports, and review articles, a further 62, 6, and 3 articles concerning anterior, lateral, and posterior cutaneous nerve entrapment syndromes, respectively, were included. These syndromes are usually diagnosed based solely on unique history and examination findings; however, the diagnostic process may be prolonged, and multiple re-evaluations are required. The most common first-line treatment is trigger point injection; however, the management of refractory cases remains unclear. Awareness of this disease should be expanded to medical departments other than general medicine.

In vitro culture of muscle cells derived from myofascial trigger points.

OBJECTIVE: To examine for the in vitro existence of contractile nodules on the taut band of muscle fibers where myofascial trigger points (MTrPs) are located (using cell culture). METHODS: Sixteen male Sprague-Dawley rats (7 weeks old) were randomly divided into experimental and control groups. A blunt striking injury and eccentric exercise were applied to the gastrocnemius muscle of rats in the experimental group once a week for 8 weeks to establish an MTrP model. Subsequently, the rats were reared normally and rested for 4 weeks. After modeling, the skeletal muscles at the MTrPs (and non-MTrPs at the same anatomical position) were extracted from the two groups of rats for in vitro cell culture experiments of single muscle fibers. Potential contractile nodules in the MTrP group were exposed to different concentrations of acetylcholinesterase, whereas non-MTrP cells were exposed to acetylcholine. The morphological changes of muscle cells in each group were observed. RESULTS: By culturing MTrP cells in vitro, large contractile nodules remained in single MTrP muscle fibers, whereas some contractile nodules were twisted and deformed. After the addition of different acetylcholinesterase concentrations, no obvious morphological changes were observed in the contractile nodules in the MTrP group. After the non-MTrP cells were exposed to different acetylcholine concentrations, no significant morphological changes were observed in the single muscle fibers. CONCLUSION: MTrP cells can continue to maintain contractile morphology in vitro, but whether the recovery of such contractile nodules is related to acetylcholine remains uncertain.

Dry needling, trigger point electroacupuncture and motor point electroacupuncture for the treatment of myofascial pain syndrome involving the trapezius: a randomised clinical trial.

OBJECTIVE: The objective of this study was to compare trigger point (TrP) dry needling, TrP electroacupuncture and motor point electroacupuncture of the trapezius muscle for the treatment of myofascial pain syndrome (MPS). METHODS: This randomised clinical trial included 90 patients divided into three groups. Group 1 was treated with dry needling of TrPs, group 2 with intramuscular electrical stimulation of TrPs, and group 3 with electroacupuncture of motor points and/or the spinal accessory nerve. Each group received seven treatment sessions. The outcomes were the pain score measured by visual analogue scale (VAS) and quality of life evaluated by the 12-item short form (SF-12) health questionnaire. We compared the pain outcome over serial time points using growth curve analysis methods. RESULTS: Participants in the three groups experienced significant improvements in pain scores over time. The average pain level of participants in group 3 across the repeated assessments was 0.98 units lower than in group 1 (mean difference (95% confidence interval (CI) = 1.74-0.23)), p = 0.012). There were no significant differences in pain scores between participants in groups 1 and 2, and there were no significant differences in quality of life across the three groups at the end of the treatment period. CONCLUSION: Our results provide evidence that electrical stimulation of motor points and/or of the spinal accessory nerve may be superior in terms of pain relief (but not quality of life) to dry needling and possibly electrical stimulation of trigger points for the management of MPS involving the trapezius. TRIAL REGISTRATION NUMBER: TRIAL-RBR-43R7RF (Brazilian Clinical Trials Registry).