Continuing Education Activity

Myofascial pain syndrome is a musculoskeletal condition characterized by regional pain within the muscle, fascia, or surrounding soft tissue. This condition often presents with localized or referred pain, typically associated with hyperirritable trigger points within taut bands of skeletal muscle. Myofascial pain syndrome can be classified into acute and chronic forms, with the latter persisting for 6 months or longer and having a worse prognosis. The exact cause remains unclear, although muscle overload due to overuse or disuse is a key factor.

Diagnosis is primarily clinical, based on the presence of trigger points, specific pain referral patterns, and local twitch responses. Imaging and electrophysiological tests can help rule out other musculoskeletal conditions. Treatment aims to relieve pain and address underlying causes through both pharmacological and nonpharmacological approaches. Effective management often requires a multimodal approach to prevent symptom recurrence, including ergonomic, psychological, and nutritional interventions. This activity for healthcare professionals is designed to enhance the learner's competence in recognizing the clinical features of myofascial pain syndrome, performing the recommended evaluation, and implementing an appropriate interprofessional management approach to improve patient outcomes.

Objectives:

• Identify characteristic clinical features of myofascial pain syndrome.

• Apply recommended diagnostic studies to evaluate myofascial pain syndrome.

• Implement evidence-based pharmacologic and nonpharmacologic treatment strategies for myofascial pain syndrome.

• Collaborate with an interprofessional team, including physical therapists, pain specialists, and psychologists, to optimize patient care.

Introduction

Myofascial pain syndrome is a condition characterized by regional pain within the muscle, fascia, or surrounding soft tissue. Although the disorder lacks a unified diagnostic criterion, patients typically present with localized pain in a restricted area or referred pain of various patterns. Physical examination reveals hyperirritable areas within taut bands of skeletal muscle, known as trigger points. Risk factors include trauma, poor posture, structural abnormalities, and systemic conditions, such as vitamin D deficiency or hypothyroidism.

Myofascial pain syndrome can be divided into acute and chronic forms. Acute myofascial pain syndrome frequently resolves spontaneously or after simple treatments. In contrast, chronic myofascial pain syndrome typically lasts for 6 months or longer and has a worse prognosis. Treatment aims to relieve pain and address underlying causes through pharmacological options, such as nonsteroidal anti-inflammatory drugs (NSAIDs), muscle relaxants, and antidepressants, and nonpharmacological interventions, such as physical therapy, dry needling, and acupuncture. Psychological interventions may also be beneficial, particularly for patients with concurrent depression or anxiety. Effective management often requires a multimodal approach to prevent symptom recurrence, including ergonomic modifications and addressing nutritional deficiencies.

Etiology

The etiology of myofascial pain syndrome is not yet fully understood, although muscle overload is thought to be a cause as a consequence of overuse or disuse.[1] Common risk factors include:

• Traumatic factors, such as muscle injury
• Ergonomic factors, such as overuse activities and poor posture
• Structural factors, such as spondylosis, scoliosis, and osteoarthritis
• Systemic factors, such as hypothyroidism, vitamin D deficiency, and iron deficiency

Epidemiology

The exact prevalence of myofascial pain syndrome in the general population is rarely mentioned in the existing literature, likely due to the lack of standardized diagnostic criteria. Sources claim that myofascial pain syndrome affects from 30% to 93% of patients seeking care for musculoskeletal pain.[2][3] Although typically found in the population aged from 27 to 50, the disorder can also affect older and high-risk populations, such as those with sedentary lifestyles, athletes, or workers who have physically demanding jobs.[2][3] The most frequently affected areas include the neck, shoulders, and back.[2] The gender difference in the incidence of myofascial pain syndrome remains unclear.

Pathophysiology

Despite extensive research and formulation of various hypotheses, the exact pathophysiology of myofascial pain syndrome is still unknown. One of the most accepted theories is the energy crisis of muscle fibers.[4] Repetitive or prolonged activity can overload muscle fibers, leading to muscle hypoxia and ischemia. Energy depletion causes calcium pumps to become dysfunctional, leading to increased intracellular calcium and sustained muscle contraction responsible for taut band development. This persistent contraction further exacerbates the oxygen demand and hypoxic injury to the muscles. Nociceptors and chemoreceptors release prostaglandins and cytokines in response to ischemia and hypoxia. These substances activate nearby nerve endings, initiating pain signals and pathways.

Consequently, neurotransmitters such as serotonin and norepinephrine are released, modulating pain transmission and contributing to a cycle of sustained muscle contraction and pain. This process reinforces the release of these neurotransmitters, further influencing pain transmission and perpetuating the cycle of muscle contraction and discomfort.[4] The subsequent inflammatory mediators released by injured myocytes contribute to pain and tenderness in the affected regions. In addition to this hypothesis, several other theories, including neurogenic inflammation, sensitization, and limbic dysfunction, have been proposed as contributing factors to myofascial pain syndrome.

Histopathology

Previous studies have reported the histopathology of trigger points of muscles in animal and human models. Light microscopic examination of trigger points revealed contraction knots (local contraction of muscle fibers) and narrowing endomysium (spaces between muscle fibers).[5][6][7] In addition, electron microscopy demonstrated a decreasing number of mitochondria and a shortening of sarcomeres.[8]

History and Physical

Clinical Features

Myofascial pain syndrome is primarily a clinical diagnosis. Therefore, the recognition of its characteristic clinical features is essential. Most patients with myofascial pain syndrome suffer from local muscle pain and referred pain in specific patterns. For example, myofascial pain in the infraspinatus muscle typically refers to the anterior deltoid area, lateral aspect of the arm, and radial half of the hand. The onset of pain may be acute or insidious. In some patients, symptoms occur after muscle injuries or overuse activities. On the other hand, certain patients can develop symptoms without identifiable precipitating factors. Associated symptoms may include muscle stiffness, reduced range of motion, dysautonomia, proprioceptive disorder (common in head and neck myofascial pain syndrome), insomnia, and depression.

During the physical examination, palpation reveals taut bands of contracted muscle in the affected region. Compression or acupuncture of markedly tender spots, known as trigger points, within the taut bands may elicit local pain, local twitch response (a rapid local muscle contraction after palpation or needling), or referred pain.[2] Trigger points can be active or latent found in symptomatic and asymptomatic patients, respectively.[9]

Although no uniform criterion exists, many clinical diagnostic criteria for myofascial pain syndrome have been utilized. Most myofascial pain syndrome criteria consist of the presence of trigger points, recognition of pain when palpating the trigger points, specific pain referral patterns, and a local twitch response.[10]

Evaluation

Diagnosis is typically based on history and physical, but additional testing can aid myofascial pain syndrome evaluation. For instance, trigger points can be identified by detecting end-plate noise through electromyography.[9] Diagnostic ultrasound enables direct visualization of trigger points as areas of hypoechogenicity compared to the surrounding muscles.[11][12][13]

Perhaps the most valuable aspect of medical imaging and electrophysiological examinations is their ability to assess for other musculoskeletal disorders. Diagnostic ultrasound can exclude bursitis and tendinopathy. Plain radiographs can evaluate structural bony defects, including spondylosis, scoliosis, and foraminal stenosis. Electromyography can be used to detect neuromuscular diseases. Finally, laboratory tests can reveal potential hormone and nutritional deficiencies relevant to myofascial pain syndrome.

Treatment / Management

The goals of myofascial pain syndrome treatment are pain relief and, more importantly, the correction of precipitating factors to avoid relapse in symptoms. A wide range of pharmacological and nonpharmacological therapies exist for myofascial pain syndrome.[2][1]

Pharmacological Therapies

The following considerations are recommended for pharmacological treatments:

• Nonsteroidal anti-inflammatory drugs: Despite being the most commonly prescribed analgesic for myofascial pain syndrome, there is currently a lack of randomized controlled trials (RCTs) to evaluate the use of NSAIDs for treating myofascial pain syndrome. Although NSAIDs are effective at treating acute musculoskeletal pain, which has a degree of overlap with myofascial pain syndrome, their long-term use necessitates caution due to the gastrointestinal, renal, and hematologic adverse effects associated with chronic consumption.

• Muscle relaxants: These agents are recommended as adjuncts to NSAID monotherapy for myofascial pain syndrome with muscle spasms or when NSAID monotherapy shows limited effectiveness.

• Lidocaine patch: Several RCTs and case reports demonstrate transdermal lidocaine as a promising therapy for myofascial pain syndrome.

• Anticonvulsants: Gabapentin and Pregabalin decrease the release of neurochemicals, such as substance P, noradrenaline, and glutamate. Although they may be considered for treatment, no RCTs have evaluated their efficacy in myofascial pain syndrome to date.

• Antidepressants: Tricyclics and serotonin-norepinephrine reuptake inhibitors alleviate psychological symptoms, which are often a component or contributor to myofascial pain. Adverse effects include dry mouth, vision changes, and constipation. Initiating these antidepressants at a low dosage and titrating up gradually to the most effective dosage is recommended.

• Opioids: Myofascial pain syndrome is generally not an indication for opioids. Most studies do not support its use for myofascial pain, and some suggest that it may be counterproductive.

Nonpharmacological Therapies

Physical modalities have a significant role in myofascial pain syndrome management. All patients should be educated about stretching exercises and ergonomic modification. Many studies found that extracorporeal shockwave and low-power lasers significantly reduce pain in patients with myofascial pain syndrome.[14] Laser therapy, manual therapy, and extracorporeal shockwave therapy can help reduce pain intensity and disability related to myofascial pain.[15] 

Transcutaneous electrical nerve stimulation provides short-term pain relief but lacks long-term efficacy. Although therapeutic ultrasound is commonly used for myofascial pain syndrome, its benefits remain inconclusive.[16] Patients with myofascial pain showed greater tolerance to pain when ischemic compression therapy was applied.[17]

In some patients, clinicians can use more invasive methods to treat myofascial pain syndrome. Dry needling is a valuable technique in which clinicians use a small needle to release trigger points. Clinicians can also inject a local anesthetic into trigger points to achieve better pain reduction. Systematic reviews confirmed that dry needling and local anesthetic injection have therapeutic effects on myofascial pain syndrome.[18] Both dry needling and trigger point manual therapy are effective at reducing pain and restoring function in the short-to-medium term. Neither has been proven to be superior to the other.[19]

Acupuncture can also treat myofascial pain syndrome.[20][21] In addition, because mental health factors may impact myofascial pain syndrome symptoms, such as depression, which may lower the pain threshold or augment the pain level, psychological interventions such as biofeedback and cognitive behavioral therapy are options to consider.[2]

Successful treatment of chronic myofascial pain syndrome ultimately depends on addressing perpetuating factors. For example, patients with vitamin D deficiency may have poor or short-lasting responses to conventional therapies and thus require vitamin D supplementation to achieve a curative effect. 

Differential Diagnosis

Many diseases present with regional pain similar to myofascial pain syndrome. Common disorders that should be ruled out through clinical examination and investigation include tendinopathy, arthritis, bursitis, and nerve entrapment. Differential diagnosis depends on the patterns and location of pain. For example, patients who have suffered from medial elbow pain should be evaluated for possible medial epicondylitis or cubital tunnel syndrome. 

For patients who have chronic multiple trigger points, fibromyalgia should be considered.[22] Fibromyalgia is a condition of widespread chronic pain. Fibromyalgia differs from chronic myofascial pain syndrome in two primary ways. First, patients with fibromyalgia have diffuse muscle tender points without taut bands and referred pain. Careful palpation in the affected area can distinguish between myofascial pain syndrome and fibromyalgia. Second, patients with fibromyalgia typically have comorbid conditions, such as depressive mood, insomnia, dizziness, dysmenorrhea, and numbness. These symptoms are rarely observed in myofascial pain syndrome. 

Staging

Myofascial pain syndrome is commonly classified as acute or chronic. Patients with acute myofascial pain syndrome have pain in one or two local regions. Symptoms typically begin after traumatic events or overuse activities. Most symptoms resolve after a few weeks. However, some patients may progress to chronic myofascial pain syndrome, which persists for 6 months or longer. Patients with chronic myofascial pain syndrome have more widespread pain compared to those with the acute form. Pain intensity may fluctuate.[17] Nearly all patients with chronic myofascial pain syndrome have some form of exacerbating factors.[22]

Prognosis

The prognosis of myofascial pain syndrome depends on the duration of symptoms. In acute myofascial pain syndrome, symptoms typically resolve spontaneously or after simple treatments, such as heat physical modalities, stretching exercises, trigger point needling, or local anesthetic injection. In contrast, chronic myofascial pain syndrome lasts much longer compared to the acute form. In a previous study, the average duration of symptoms was 63 months, and the range was between 6 and 180 months. Chronic myofascial pain syndrome may become recalcitrant if the underlying medical condition is not corrected.[22]

Complications

Myofascial pain syndrome can lead to several complications if left untreated or improperly managed. Chronic myofascial pain syndrome may result in persistent pain, significantly reducing a patient's quality of life and leading to functional impairment, decreased range of motion, and muscle weakness. The condition can also contribute to psychological distress, including anxiety, depression, and sleep disturbances, as ongoing pain disrupts daily activities and rest. In addition, prolonged muscle tension and dysfunction may cause postural imbalances, increasing the risk of secondary musculoskeletal issues such as joint dysfunction and referred pain syndromes. Effective management is crucial to prevent these complications and improve patient outcomes.

Deterrence and Patient Education

Deterrence and patient education play a crucial role in managing myofascial pain syndrome and preventing symptom recurrence. Patients should be educated on the importance of maintaining proper posture, engaging in regular stretching and strengthening exercises, and avoiding repetitive strain or muscle overuse. Ergonomic modifications at work and home can help reduce unnecessary muscle stress, whereas stress management techniques such as relaxation exercises and mindfulness may prevent muscle tension from worsening symptoms. Encouraging patients to adopt a healthy lifestyle, including proper nutrition and adequate sleep, can also enhance recovery and reduce the risk of chronic pain.

Patients should be informed about treatment options, including physical therapy, dry needling, and nonpharmacological pain relief strategies, empowering them to take an active role in their care. Understanding the role of trigger points and early symptom recognition can help individuals seek timely interventions before the condition progresses. Addressing potential contributing factors, such as vitamin D deficiency or underlying systemic conditions, can improve treatment effectiveness. By fostering patient engagement and adherence to a comprehensive management plan, clinicians can enhance long-term outcomes and reduce the burden of chronic myofascial pain syndrome.

Enhancing Healthcare Team Outcomes

Effective management of myofascial pain syndrome requires a coordinated interprofessional approach to enhance patient-centered care, improve outcomes, and ensure patient safety. Clinicians and advanced practitioners play a central role in diagnosing myofascial pain syndrome, formulating individualized treatment plans, and coordinating care among specialists. Pain specialists should be involved early to establish an accurate diagnosis and initiate appropriate interventions. Nurses play a vital role in educating patients, managing medications, and monitoring the effectiveness of treatments. Physical therapists provide rehabilitation strategies to correct posture, optimize muscle function, and prevent recurrence. Pharmacists ensure the safe and effective use of medications, educating patients on potential adverse effects and interactions. Mental health professionals can support patients dealing with depression, anxiety, or other psychological factors that may contribute to or exacerbate myofascial pain syndrome symptoms.

Given the complexity and variability of myofascial pain syndrome, interprofessional communication is vital to ensure cohesive and effective care. Regular team discussions and shared decision-making help tailor treatment plans to individual patient needs. Clinicians and advanced practitioners should remain flexible in treatment approaches, recognizing that no single intervention is universally effective. Patients may explore alternative therapies, necessitating open dialogue and guidance to ensure the safe and complementary use of such methods. Care coordination should also emphasize long-term management strategies, including ergonomic modifications, stress reduction, and lifestyle changes, to prevent symptom recurrence. By fostering collaboration among healthcare professionals, improving patient education, and implementing comprehensive treatment strategies, the interprofessional team can enhance both patient outcomes and overall team performance in managing myofascial pain syndrome.