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.

Dry needling of the flexor digitorum brevis muscle reduces postural control in standing: A pre-post stabilometric study.

There are studies that show the better balance after dry needling in lumbar pain. However, the postural control effects after foot dry needling are unknown. Our objective was to check if dry needling reduces postural control. Eighteen subjects with flexor digitorum brevis (FDB) muscle Myofascial trigger point were evaluated pre- and post-deep dry needling. We measured stabilometric variables in a pre-post study. We have found significant differences in three stabilometric variables: surface with eyes closed (29.36-53.21 mm2 ) (p = 0.000), medium speed of the laterolateral displacement with eyes closed (1.42-1.64 mm/s) (p = 0.004), and medium speed of the anteroposterior displacement with eyes closed (1.30-1.53 mm/s) (p = 0.025). Dry needling therapy application in FDB muscle reduces standing postural control with eyes closed.

Exploring the Underlying Mechanisms of Action of Dry Needling: What Is the Immediate Effect on Muscle Electrophysiology? An Experimental Randomized Controlled Trial.

OBJECTIVE: Dry needling is a commonly used treatment technique for myofascial pain syndromes, such as trapezius myalgia. Despite the shown positive clinical effects on pain, the underlying mechanisms of action, such as the effect on muscle electrophysiology, remain unclear. The aim of this study was to investigate the effect of dry needling, compared with sham needling, in the upper trapezius muscle on surface electromyography activity and the relation with pain in office workers with trapezius myalgia. DESIGN: For this experimental randomized controlled trial, 43 office workers with work-related trapezius myalgia were included. Surface electromyography activity was measured before and after a pain-provoking computer task and immediately after, 15, and 30 mins after treatment with dry or sham needling. Pain scores were evaluated at the same time points as well as 1, 2, and 7 days after treatment. RESULTS: No significant differences in surface electromyography activity between dry needling and sham needling were found. Significant positive low to moderate Spearman correlations were found between surface electromyography activity and pain levels after dry needling treatment. CONCLUSIONS: This study shows no immediate effects of dry needling on the electrophysiology of the upper trapezius muscle, compared with sham needling.

Ultra-Low Frequency Transcutaneous Electrical Nerve Stimulation on Pain Modulation in a Rat Model with Myogenous Temporomandibular Dysfunction.

Masticatory myofascial pain (MMP) is one of the most common causes of chronic orofacial pain in patients with temporomandibular disorders. To explore the antinociceptive effects of ultra-low frequency transcutaneous electrical nerve stimulation (ULF-TENS) on alterations of pain-related biochemicals, electrophysiology and jaw-opening movement in an animal model with MMP, a total of 40 rats were randomly and equally assigned to four groups; i.e., animals with MMP receiving either ULF-TENS or sham treatment, as well as those with sham-MMP receiving either ULF-TENS or sham treatment. MMP was induced by electrically stimulated repetitive tetanic contraction of masticatory muscle for 14 days. ULF-TENS was then performed at myofascial trigger points of masticatory muscles for seven days. Measurable outcomes included maximum jaw-opening distance, prevalence of endplate noise (EPN), and immunohistochemistry for substance P (SP) and µ-opiate receptors (MOR) in parabrachial nucleus and c-Fos in rostral ventromedial medulla. There were significant improvements in maximum jaw-opening distance and EPN prevalence after ULF-TENS in animals with MMP. ULF-TENS also significantly reduced SP overexpression, increased MOR expression in parabrachial nucleus, and increased c-Fos expression in rostral ventromedial medulla. ULF-TENS may represent a novel and applicable therapeutic approach for improvement of orofacial pain induced by MMP.

Inhibition of Peripheral ERK Signaling Ameliorates Persistent Muscle Pain Around Trigger Points in Rats.

The purpose of this study was to investigate whether the ERK signaling pathway was involved in ameliorating chronic myofascial hyperalgesia from contused gastrocnemius muscle in rats. We established an animal model associated with myofascial pain syndrome and described the mechanism of muscle pain in an animal model. Changes in the mechanical pain threshold were observed 0.5, 1, 2, 3, 4, 5, 8, 12, 18, and 24 h after ERK inhibitor injection around myofascial trigger points (MTrPs) of the gastrocnemius muscle in rats. Morphological changes in gastrocnemius muscle cells were observed by hematoxylin and eosin (H&E) staining. ERK signaling pathway activation was detected through immunohistochemistry and Western blotting. The main morphological characteristics of injured muscle fibers around MTrPs include gathered circular or elliptical shapes of different sizes in the cross-section and continuous inflated and tapering fibers in the longitudinal section. After intramuscular injection of U0126 (ERK inhibitor), the mechanical pain threshold significantly increased. The reduction in mechanical hyperalgesia was accompanied by reduced ERK protein phosphorylation, myosin light chain kinase (MLCK) protein, p-MLC protein expression, and the cross-sectional area of skeletal muscle cells around MTrPs. An ERK inhibitor contributed to the attenuation of mechanical hyperalgesia in the rat myofascial pain model, and the increase in pain threshold may be related to MLCK downregulation and other related contraction-associated proteins by ERK.

Treatment and management of myofascial pain syndrome.

Myofascial Pain Syndrome (MPS) is a regional pain disorder that affects every age-group and is characterized by the presence of trigger points (TrPs) within muscles or fascia. MPS is typically diagnosed via physical exam, and the general agreement for diagnostic criteria includes the presence of TrPs, pain upon palpation, a referred pain pattern, and a local twitch response. The prevalence of MPS among patients presenting to medical clinics due to pain ranges anywhere from 30 to 93%. This may be due to the lack of clear criteria and guidelines in diagnosing MPS. Despite the prevalence of MPS, its pathophysiology remains incompletely understood. There are many different ways to manage and treat MPS. Some include exercise, TrP injections, medications, and other alternative therapies. More research is needed to form uniformly-accepted diagnostic criteria and treatments.

Effects of 4-Week Diacutaneous Fibrolysis on Myalgia, Mouth Opening, and Level of Functional Severity in Women With Temporomandibular Disorders: A Randomized Controlled Trial.

OBJECTIVE: The purpose of this study was to assess the effects of 4-week protocol of diacutaneous fibrolysis (DF) compared with simulated DF (sham-DF) on myalgia and mouth opening. METHODS: In a sham randomized controlled trial, 34 women with temporomandibular disorders and myofascial pain were randomly divided as intervention group (IG) and sham-DF group (SG). The IG received 4 weeks of real DF, and the SG received sham. Pain was assessed through the visual analog scale and pressure pain thresholds (PPTs) on the temporomandibular joint (TMJ), and over the temporal and masseter muscles. The Mandibular Function Impairment Questionnaire was used to classify the participants regarding to the severity of the functional limitation related to TMD. RESULTS: Pain scores decreased for both groups, but the IG showed lower values at week 4, with between-group differences. Bilateral temporal PPT showed higher values at week 4, with between-group differences. The SG had lower PPTs but the IG had higher PPTs, both compared to baseline results. The time-by-group interaction and the frequency of participants above 40 mm of mouth opening showed a significant difference for the IG over time with higher results at the 4-week assessment compared to its own baseline. Both groups showed lower MFIQ scores from baseline to 4-week assessment. There was a lower frequency of a moderate level of severity for the IG. No differences were observed for TMJ or for the masseter muscles PPT. CONCLUSION: Improvements were observed for visual analog scale scores and PPTs on temporal muscles. There was a group-by-time interaction in the IG, suggesting a possible potential use of DF for mouth opening.

A Comprehensive Review of the Treatment and Management of Myofascial Pain Syndrome.

PURPOSE OF REVIEW: Myofascial pain syndrome (MPS) is a musculoskeletal pain condition that stems from localized, taut regions of skeletal muscle and fascia, termed trigger points. The purpose of this comprehensive review is to provide updated information on prevalence, pathophysiology, and treatment modalities with a focus on interventional modalities in managing MPS. RECENT FINDINGS: Though MPS can present acutely, it frequently presents as a chronic condition, affecting up to 85% of adults during their lifetime. MPS is an often-overlooked component of pain with overarching effects on society, including patient quality of life, physical and social functioning, emotional well-being, energy, and costs on health care. The prevalence of MPS is generally increased among patients with other chronic pain disorders and has been associated with various other conditions such as bladder pain syndrome, endometriosis, and anxiety. MPS is poorly understood and remains a challenging condition to treat. Non-pharmacologic treatment modalities such as acupuncture, massage, transcutaneous electrical stimulation, and interferential current therapy may offer relief to some patients with MPS. Additional studies are warranted to get a better understanding of managing myofascial pain.

Acute effects of myofascial induction technique in plantar fascia complex in patients with myofascial pain syndrome on postural sway and plantar pressures: A quasi-experimental study.

OBJECTIVES: The prevalence of myofascial pain syndrome varies from 21% 93%. Several studies have shown that myofascial induction is effective in treating myofascial pain syndrome. Although these techniques have shown some effectiveness in clinical practice, there have been little study into their effects, and have deep effects. The purpose of this study was to investigate if the application of a single myofascial induction technique for each foot, targeted to the plantar fascia resulted in changes in balance and footprint variables. DESIGN: A quasi-experimental study. SETTING: An outpatient clinic. SUBJECTS: 20 healthy participants (12 females and 8 males) were evaluated pre and post Myofascial induction technique for each foot in plantar fascia during 5 min. METHODS: We measured static footprint and stabilometry variables in asymptomatic subjects. The footprint surface area was divided: bilateral rear foot, bilateral midfoot, bilateral fore foot. RESULTS: We found differences in the footprint variables: maximun pressure in forefoot (p = 0.025), surface in forefoot (p = 0.03). The myofascial induction has no effects on stabilometry variables. CONCLUSIONS: The immediate effects of the longitudinal technique of myofascial induction of the plantar fascia are the increase of surface and maximum pressure in fore foot.

Relationship between muscle spindles and myofascial trigger spots according to Hoffmann reflex pathway and tissue morphology characteristics in a rat model.

OBJECTIVES: To determine how muscle spindles are involved in the pathophysiology of chronic myofascial trigger spots (MTrSs, similar to myofascial trigger points) in a rat injury model according to the characteristics of the Hoffmann reflex (H-reflex) and the anatomical relationship between muscle spindles and MTrSs. METHODS: 16 male Sprague-Dawley rats (7 weeks old) were randomly divided into experimental and control groups. A blunt strike injury and eccentric exercise were applied to the gastrocnemius muscle of rats in the experimental group once a week for 8 weeks as a MTrS modelling intervention. Subsequently, the rats were reared normally and rested for 4 weeks. At the end of the 12th week, the rats were examined for the presence of MTrSs defined by the detection of a palpable taut band exhibiting both a local twitch response and spontaneous electrical activity. After modelling, evocation of the H-reflex and morphological examination of muscle spindles and MTrSs were conducted. RESULTS: The threshold (0.35±0.04 mA) of the H-reflex and latency (1.24±0.18 ms) of the M wave recorded at MTrSs were not significantly different to those at non-MTrSs (P>0.05). Compared with non-MTrSs, a lower Mmax (4.28±1.27 mV), higher Hmax (median (IQR) 0.95 (0.80-1.08) mV) and Hmax/Mmax (median (IQR) 0.21 (0.16-0.40)), and shorter H wave latency (4.60±0.89 ms) were recorded at MTrSs (P<0.05). Morphologically, there was a close anatomical relationship between the MTrS cells and the muscle spindles. DISCUSSION: Compared with normal muscles, the H-reflex myoelectrical activity was enhanced and some muscle spindles might have been influenced by active MTrSs. Thus, muscle spindles may play an important role in the pathological mechanism underlying myofascial trigger points.

Ultrasound Imaging of the Paraspinal Muscles for Interscapular Pain After Back Massage.

Muscle injuries are very common in sports medicine, but involvement of the paraspinal muscles is relatively rare. The diagnosis is usually clinical, but diagnostic imaging modalities (ie, ultrasound and magnetic resonance) identify, in detail, the anatomical site and extension of the lesion helping the physician plan a specific rehabilitation program. Likewise, the authors present an unusual case of a amateur volleyball player who suffered injury of the paraspinal muscles after a session of manual therapy with deep massage. The authors also highlight the potential role of ultrasound imaging in detecting muscle injuries not only in the limbs but also at the level of paraspinal region for prompt management and return to play.

Myofascial pain and treatment: Editorial a critical overview of the current myofascial pain literature - August 2019.

This quarter's overview of the myofascial pain literature includes quite a few basic research papers in addition to the usual high quantity of dry needling (DN) papers. Of particular interest are a study by Fischer and colleagues studying the role of mitochondrial functions in chronic trigger points (TrPs) (Fischer et al 2018), a study by Li and associates who conducted a quantitative proteomics analysis to identify biomarkers of chronic myofascial pain and therapeutic targets of dry needling in a rat model of TrPs (Li et al 2019), and a sonography study by Mitchell et al. looking into the distances from the skin to the pleura in the context of DN (Mitchell et al 2019). A total of 33 papers are included in this overview article. We welcome Dr. Jacob Thorp to our team of authors. Dr. Thorp is a US-based physical therapist. He is Professor and Founding Director of the Physical Therapy Program at Charleston Southern University in North Charleston, SC.

Myofascial pain and treatment: Editorial.

The first article featured in this quarter's overview deserves special attention. Margalef and colleagues developed the first viable animal model of trigger points (TrPs). They also provided evidence of glycosaminoglycans (GAGs) near TrPs, which is a new finding that deserves further scientific inquiry (Margalef et al 2019). In 2011, Stecco et al. already mentioned a possible role of hyaluronan, which constitutes a subgroup of GAGs, in the etiology of myofascial pain (Stecco et al 2011). Mayoral Del Moral and colleagues published an excellent study that showed very good inter-examiner reliability for identifying subjects with MPS for identifying specific muscles (Mayoral Del Moral et al 2018). Sollmann and colleagues described a new and objective method to identify TrPs, using T2 mapping with quantitative MRI-based techniques (Sollmann et al 2016). As usual, many new dry needling (DN) studies, reviews, manual TrP papers and case reports are included. Finally, we would like to thank Dr. Michelle Finnegan for her contributions to this overview paper during the past 5 years. Dr. Finnegan will be focusing on other professional endeavors and she will not return as a contributing author.

Proximal myofascial pain in patients with distal complex regional pain syndrome of the upper limb.

BACKGROUND: Patients suffering from complex regional pain syndrome (CRPS) endure myofascial-related pain in at least 50% of cases. AIMS: To evaluate the association of upper limb CRPS with myofascial pain in muscles that might influence arm or hand pain, and to evaluate whether the paraspinal skin and subcutaneous layers' tenderness and allodynia are associated with CRPS. METHODS: A case-control study comprising 20 patients presenting with upper limb CRPS, and 20 healthy controls matched for sex and age, were evaluated in the thoracic paraspinal area and myofascial trigger points (MTrPs) (infraspinatus, rhomboids, subclavius, serratus posterior superior and pectoralis minor) via a skin rolling test. RESULTS: The prevalence of MTrPs in the affected extremity of the subjects was significantly higher than in the right limb of the controls: 45% exhibited active and latent MTrPs in the infraspinatus muscle (χ2 = 11.613, p = 0.001); 60% in active and latent MTrPs in the subclavius muscle (χ2 = 17.143, p < 0.001); and in the pectoralis minor muscle (χ2 = 13.786, p < 0.001). In addition, 55% of the cases exhibited active and latent MTrPs in the serratus posterior superior muscle (χ2 = 15.172, p < 0.001). Significant differences between the groups in skin texture and pain levels (p = 0.01, p < 0.001, respectively) demonstrated that CRPS patients felt more pain, and their skin and subcutaneous layers were much tighter than in the healthy controls. CONCLUSION: There is a high prevalence of MTrPs in the shoulder and upper thoracic area muscles in subjects who suffer from CRPS. We recommend adding an MTrPs evaluation to the standardized examination of these patients.

Myofascial pain syndrome and trigger points: evaluation and treatment in patients with musculoskeletal pain.

PURPOSE OF REVIEW: Myofascial pain syndrome is a chronic pain condition characterized by the presence of myofascial trigger point, a hyperirritable painful spot involving a limited number of muscle fibers. The literature suggest that myofascial trigger points should be considered peripheral pain generators and this critical review will summarize recent findings concerning the clinical evaluation and the treatment of myofascial trigger points. RECENT FINDINGS: The clinical features of myofascial trigger points and their contribution to the patient pain and disability have been detailed in several recent studies, which support the clinical relevance of the condition. Recent studies reported that manual palpation to identify MTrPs has good reliability, although some limitations are intrinsic to the diagnostic criteria. During the last decade, a plethora of treatments have been proposed and positive effects on pain and function demonstrated. SUMMARY: The myofascial trigger point phenomenon has good face validity and is clinically relevant. Clinicians are encouraged to consider the contribution of myofascial trigger points to the patient's pain and disability through a careful medical history and a specific manual examination. Patients with myofascial trigger points will benefit from a multimodal treatment plan including dry needling and manual therapy techniques. Internal and external validity of research within the field must be improved.

Interventions for myofascial pain syndrome in cancer pain: recent advances: why, when, where and how.

PURPOSE OF REVIEW: Pain is one of the most feared and most common symptoms of cancer, experienced by 38-85% of patients. Pain in terminally ill cancer patients is a multidimensional experience caused by a diverse array of factors - cancer itself, its treatment or other causes. Studies have shown a high incidence of myofascial pain syndrome (MPS) in patients with cancer and the knowledge of myofascial trigger points (MTrPs) is important to address and manage existing pain, and to prevent the recurrence of pain. This review aims to summarize recent advances in interventions for managing MPS in patients with cancer. RECENT FINDINGS: Database searches were conducted on MEDLINE, CINAHL, and Google Scholar to locate all studies published from inception until April 2019 using the keywords cancer pain, myofascial pain, TrPs with emphasis of any methodological quality that included interventions for MPS. MPS in advanced cancer patients are more commonly observed along with other cancer pains rather than independently with a prevalence of 11.9-48% in those patients diagnosed with cancer of head and neck and breast cancer. SUMMARY: Interventional therapies employing ultrasound guided injection of the MTrPs is gaining popularity in the management of MPS in cancer pain and may be a better alternative than the use of opioid analgesics in the multidisciplinary management.

A critical overview of the current myofascial pain literature - February 2019.

This edition of the overview of current myofascial pain literature features several interesting and important publications. From Australia, Braithwaite and colleagues completed an outstanding systematic review of blinding procedures used in dry needling (DN) studies. Other papers tackled the interrater reliability of the identification of trigger points (TrP), the presence of muscle hardness related to latent TrPs, pelvic floor examination techniques, and the links between TrPs, headaches and shoulder pain. Israeli researchers developed a theoretical model challenging the contributions of the Cinderella Hypothesis to the development of TrPs. As in almost all issues, we included many DN, injection and acupuncture studies, which continue to be the focus of researchers all over the world.

Myofascial component of cancer pain review.

BACKGROUND: Pain is a common complaint of cancer patients, experienced by 38%-85% of patients. Some studies have shown a high incidence of myofascial pain syndrome (MPS) in cancer patients. AIMS: 1) To estimate the prevalence of MPS in cancer patients; 2) to examine the efficacy of current treatment options for MPS in cancer patients. METHODS: Narrative review. PubMed, CINAHL, PEDro, and Google Scholar databases were searched from inception until November 2017, for the keywords: cancer; cancer pain; breast cancer; mastectomy; lumpectomy; myofascial pain; trigger points. Trials of any methodological quality were included. All published material with an emphasis on randomized control trials was analyzed. RESULTS: MPS is prevalent in cancer patients who suffer from pain, with a prevalence of between 11.9% and 44.8% in those diagnosed either with neck or head or breast cancer. Clinical studies showed conflicting results. Four interventional studies found that specific treatment for MPS may reduce the prevalence of active myofascial trigger points and therefore decrease pain level, sensitivity, and improve range of motion (in shoulder) in cancer patients. Two recent randomized control trials showed that pressure release of trigger points provides no additional beneficial effects to a standard physical therapy program for upper limb pain and function after breast cancer surgery. CONCLUSIONS: We recommend including the evaluation of myofascial pain in routine clinical examination of cancer patients suffering from pain. Future studies are needed to investigate the long- and short-term effect of MPS treatments in cancer patients.

Effects of dry needling in the sternocleidomastoid muscle on cervical motor control in patients with neck pain: a randomised clinical trial.

OBJECTIVE: To determine the changes produced by trigger point dry needling (TrP-DN) of sternocleidomastoid in patients with neck pain, and to observe how it might modify cervical motor control (CMC). DESIGN: Single-centre, randomised, double-blinded clinical trial. SETTING: Participants were recruited through advertising. The duration of the study was 6 months. SUBJECTS: Thirty-four subjects with non-specific neck pain, aged over 18 years with an active myofascial trigger point in sternocleidomastoid, participated in the study. They were randomly assigned to treatment or control groups. METHODS: TrP-DN inside or (1.5 cm) outside of the active myofascial trigger point of sternocleidomastoid. MAIN OUTCOME MEASURES: CMC, visual analogue scale and cervical range of motion were assessed before treatment, immediately post treatment, and 24 h, 1 week and 1 month after the intervention; the neck disability index was evaluated before treatment and 1 month later. RESULTS: With a confidence interval of 99%, TrP-DN of sternocleidomastoid was associated with a decrease in pain after 1 week and CMC improved 1 month after the intervention (p < 0.001), when compared with baseline measurements, within the experimental group; there were no statistically significant differences between experimental and control groups. CONCLUSION: The effects of TrP-DN inside and outside of active myofascial trigger points did not differ in this study. Both interventions were associated with a similar temporal effect, specifically a reduction in neck pain at 1 week and an increase CMC at 1 month. However, these findings should be interpreted with caution due to the lack of a contemporaneous untreated control group.

Kinesio taping versus dry needling in the treatment of myofascial pain of the upper trapezius muscle: A randomized, single blind (evaluator), prospective study.

BACKGROUND: Although a number of therapeutic interventions for trigger-point inactivation have been studied, it remains controversial which intervention is better. OBJECTIVE: To compare the effectiveness of the kinesio taping and dry needling methods in patients with trigger-point related myofascial pain syndrome of the upper trapezius muscle. METHODS: A total of 42 patients were randomly allocated to the kinesio taping group (n= 23) and dry needling group (n= 19). The patients were assessed for pain, pressure pain threshold (PPT), cervical range of motion (CROM), and function at baseline, at short- and medium-term stages after treatment. To investigate the effects of the interventions over time, two-way repeated measures analysis of variance (ANOVA) was used. RESULTS: There was a significant improvement in pain intensity at rest and cervical motion, in the PPT readings (p< 0.05), in CROM (p< 0.05), and in function (p< 0.05) in both groups, with no superiority either (p> 0.05). CONCLUSIONS: Kinesio taping may be a choice of trigger point inactivation in patients who do not want to be needled or who show contraindication(s) to treatments other than kinesio taping.