Theefficacyofintramuscularelectricalstimulationinthemanagementofpatientswithmyofascialpainsyndrome:asystematicreview

Myofascial pain syndrome (MPS) affects almost one-third of people with musculoskeletal complaints, causing chronic pain from sensitive trigger points in muscles. While treatments like dry needling, manual therapy, and exercise help, researchers have been exploring intramuscular electrical stimulation (IMES) - a technique that combines needle insertion with electrical current delivered directly into the muscle. Despite some promising early studies, the evidence has been scattered and difficult to interpret, making it hard for clinicians to know when and how to use this treatment approach.

The researchers conducted a comprehensive systematic review by searching seven major medical databases from 1990 to 2020 for randomized controlled trials that tested IMES in people with myofascial pain syndrome. They specifically looked for studies that compared IMES to sham treatment, dry needling alone, or exercise therapy. Two independent reviewers screened 397 potential studies, ultimately selecting 6 high-quality trials that met their strict criteria. They used the Cochrane risk-of-bias tool to evaluate study quality and extracted detailed information about treatment protocols, outcome measures, and results.

The 6 included studies involved 158 total patients (76 receiving IMES, 82 in control groups). Most studies focused on neck and upper shoulder trigger points, with treatment sessions ranging from 1 to 10 visits. Electrical stimulation frequencies varied from 2 to 80 Hz, with most lasting 10-20 minutes per session. The studies measured various outcomes including pain levels, range of motion, pressure pain thresholds, and functional disability.

Generally, studies with better methodological quality showed significant improvements in pain and function with IMES compared to control treatments. However, the research was limited by small sample sizes, different treatment protocols, and varying follow-up periods that prevented combining results statistically.

This review provides preliminary but encouraging evidence that IMES may be helpful for people with myofascial pain syndrome, particularly for reducing pain and improving function. The technique appears to work by delivering electrical current directly into trigger points, potentially improving blood flow and reducing muscle tension in ways that surface electrical stimulation cannot achieve. However, the current evidence comes from small studies with significant limitations. Patients and clinicians should view IMES as a potentially promising but still experimental treatment option.

The researchers emphasize that larger, better-designed trials are needed to establish optimal treatment protocols, determine which patients benefit most, and confirm long-term effectiveness before IMES can be recommended as a standard treatment approach.