MyofascialPain

Myofascial pain syndrome (MPS) is one of the most common yet frequently overlooked causes of musculoskeletal disability worldwide. It arises from acute and chronic pain within the musculoskeletal system, often with a referred neuropathic component. The condition affects more than three-quarters of the global population at some point in their lives, with prevalence estimates ranging from 21% in general orthopedic clinics to 93% in specialty pain centers. Despite its enormous impact, MPS remains underrecognized in clinical practice.

The syndrome can be primary (unrelated to other medical conditions) or secondary (associated with comorbid conditions), and is characterized by the presence of myofascial trigger points—palpably tense bands of muscle fibers that produce characteristic local twitch responses and referred pain patterns. Understanding the epidemiology, pathophysiology, and treatment options for MPS is essential for clinicians across multiple specialties.

This narrative review synthesizes current evidence on myofascial pain syndrome, drawing from published literature to provide a comprehensive overview of the condition. The authors examine the epidemiological data, explore contemporary theories of pathophysiology, and evaluate diagnostic and therapeutic approaches. For epidemiology, they compiled prevalence data from various clinical settings. For pathophysiology, they reviewed mechanisms ranging from motor end plate dysfunction to fascial involvement.

For diagnosis, they assessed clinical examination criteria and ancillary testing options. For treatment, they evaluated the spectrum of interventions from conservative physical therapy through invasive procedures including trigger point injections, dry needling, and botulinum toxin administration. The review incorporates findings from randomized controlled trials, systematic reviews, and meta-analyses where available.

The review establishes that up to 85% of people will experience myofascial pain at least once during their lifetime. The pathophysiology involves increased acetylcholine release at the motor end plate, leading to sustained sarcomere shortening, contraction knots, vasoconstriction, and relative ischemia. This triggers release of vasoactive and proinflammatory substances including prostaglandin, bradykinin, serotonin, and histamine. Autonomic involvement manifests as allodynia, blood flow changes, sweating abnormalities, and altered pilomotor response.

Chronic trigger points may develop convergent connections in the dorsal horn, activating central sensitization through substance P, NMDA, glutamate, and nitric oxide.

For diagnosis, the most frequently used criteria include palpation of at least one tender spot in a taut band (65%), limited range of motion (22%), patient pain recognition upon palpation (53%), local twitch response (44%), and predicted pain referral pattern (44%). However, no gold standard diagnostic study exists outside of physical examination.

Regarding treatment, regular exercise with slow sustained stretching is the foundation of management. Deep massage improves blood flow and lymphatic drainage while activating endorphin release. Transcutaneous electrical nerve stimulation at 100 Hz with 250 ms pulses reduces myofascial pain. Among pharmacological options, tizanidine has the best evidence of efficacy for MPS.

For invasive treatments, dry needling was found superior to sham or no treatment both immediately and for 4 weeks postintervention in a recent systematic review and meta-analysis, though it did not show significant difference compared with alternative interventions. Botulinum toxin A demonstrated improvement in pain descriptors, muscle tension, and pressure pain thresholds compared with placebo (saline) or steroid injection at 30 and 60 days posttreatment in multiple small randomized controlled trials.

This review provides clinicians with a practical framework for evaluating and treating myofascial pain syndrome. The high prevalence and significant disability associated with MPS underscore the importance of maintaining clinical suspicion, particularly in patients with persistent musculoskeletal complaints. The emphasis on physical examination as the diagnostic cornerstone means that clinicians can effectively identify MPS without expensive ancillary testing, though imaging may be useful to exclude other conditions.

For treatment, the review supports a graduated approach beginning with conservative measures. Patients should be encouraged to remain active with gentle, controlled movements and slow sustained stretching, while strength training should be deferred until pain reduction and range of motion restoration are achieved. The evidence for botulinum toxin A offers a promising option for refractory cases, though cost considerations may limit accessibility. The finding that dry needling provides equivalent pain relief to medication injection but with more postinjection soreness helps inform shared decision-making with patients.

The review also highlights important safety considerations, including contraindications to trigger point injection such as coagulopathies, anticoagulant use, local infection, acute muscle trauma, or recent antiplatelet use.

The recognition that regular vigorous activity appears protective, with middle-aged sedentary women at highest risk, has important public health implications for prevention strategies.