Acupuncture therapy on myofascial pain syndrome: a systematic review and meta-analysis

Myofascial pain syndrome represents one of the most common conditions related to chronic musculoskeletal pain, affecting up to 85% of patients who seek specialized pain clinics. This condition is characterized by the presence of highly sensitive trigger points located in taut bands of skeletal muscle, which may be caused by direct or indirect trauma, postural changes, repetitive efforts, or various physical disorders. Conventional treatment frequently involves analgesic medications and muscle relaxants, especially nonsteroidal anti-inflammatory drugs, but there are concerns about the gastrointestinal, renal, and hemorrhagic adverse effects associated with the prolonged use of these medications. In addition, scientific evidence on the efficacy of these medications for myofascial syndrome is still limited, creating a need to explore alternative therapies that are safer and more effective.

This study represents a systematic review and meta-analysis conducted by Chinese researchers with the objective of evaluating the effectiveness of acupuncture in the treatment of myofascial pain syndrome. The researchers performed a comprehensive search in multiple scientific databases, including PubMed, Cochrane Library, Web of Science, and Chinese databases, covering publications from the inception of these databases through November 2023. The methodology followed rigorous criteria, including only randomized controlled trials that compared acupuncture with other treatments for myofascial syndrome. The evaluation criteria included standardized pain scales such as the Visual Analog Scale (VAS), the Pain Rating Index (PRI), and the Present Pain Intensity (PPI), in addition to efficacy criteria specific to traditional Chinese medicine.

The methodological quality of the studies was assessed using standardized tools, and the statistical analysis used appropriate models considering heterogeneity among studies.

The results of the analysis included 10 randomized clinical trials, totaling 852 patients divided between acupuncture groups (427 patients) and control groups (425 patients). The findings were consistently favorable to acupuncture across all measures evaluated. On the Visual Analog Scale, which measures pain intensity on a scale of 0 to 10, the acupuncture group demonstrated a significantly greater reduction in pain scores compared with the control groups, with a mean difference of -1.29 points. On the Pain Rating Index, which evaluates the quality and intensity of the painful experience through specific descriptors, acupuncture showed superiority with a mean difference of -2.04 points.

Similarly, in the evaluation of Present Pain Intensity, patients treated with acupuncture had significant improvement, with a mean difference of -1.03 points compared with controls. Additionally, when evaluated by the efficacy criteria of traditional Chinese medicine, acupuncture demonstrated rates of significant improvement and overall efficacy superior to conventional treatments. Importantly, no study reported serious adverse effects related to acupuncture, suggesting a favorable safety profile.

The clinical implications of these findings are substantial for both patients and healthcare professionals. For patients suffering from myofascial syndrome, these results offer robust scientific evidence that acupuncture may be an effective and safe therapeutic option, especially considering the potential adverse effects of conventional pharmacologic treatments. The technique proved effective both when used alone and in combination with therapeutic massage, offering flexibility in treatment approaches. For healthcare professionals, including physicians, physical therapists, and acupuncturists, this study provides a solid scientific basis for incorporating or recommending acupuncture as part of an integrated treatment plan for myofascial syndrome.

Subgroup analysis demonstrated that the efficacy of acupuncture is independent of patient age or specific location of pain, whether in the cervical, shoulder, or lumbar region, broadening its clinical applicability. In addition, the favorable safety profile makes acupuncture a particularly attractive option for patients who cannot tolerate conventional medications or who prefer less invasive approaches.

Despite the promising results, the study has important limitations that should be considered in the interpretation of the findings. The significant heterogeneity observed among studies, possibly related to variations in acupuncture protocols, point selection, duration and frequency of treatments, as well as differences in control groups, represents a relevant methodological limitation. Most of the included studies presented limitations in the blinding of participants and therapists, an inherent difficulty in acupuncture studies due to the nature of the intervention. Additionally, some studies had problems in the reporting of prespecified outcomes, which may introduce publication bias.

The authors acknowledge that future studies of higher methodological quality, with more standardized designs and larger samples, are needed to definitively confirm these findings. They also suggest the need to standardize acupuncture protocols based on grounded principles of traditional Chinese medicine to improve comparability among studies and optimize therapeutic outcomes. This work represents a significant advance in the understanding of the role of acupuncture in the management of myofascial syndrome, providing scientific evidence that can guide clinical decisions and health policies related to the treatment of this prevalent and disabling condition.