Abstract
Introduction: Myofascial pain syndrome (MPS) is a prevalent chronic pain disorder that initiates from myofascial trigger points (MTrPs) in skeletal muscle. This study aimed to systematically review the studies on the efficiency of transcutaneous electrical nerve stimulation (TENS) on MPS.
Methods: The data from PubMed, EMBASE, Web of Science, and Cochrane Central Register of Controlled Trials from the database inception to July 2021 were used. Two reviewers screened the papers independently, and took out the data based on the PRISMA protocol. Information associated with the study was gathered, including glocation, time, author, modality, details of comparisons between groups, duration of treatment, participants’ characteristics, and duration of follow-up.
Results: Among 422 articles, a total of 21 articles met the exclusion and inclusion criteria for the study (including 12 trials) and 7 for meta-analysis. The overall estimated effect showed a significant decrease in Visual analog scale (VAS) score in the TENS group compared with the exercise group (MD=-1.60, 95% CI: -2.16 to -1.05, P<0.00001). However, there was no significant decrease in pain pressure threshold (PPT) score in the TENS group compared with sham (MD=1.88, 95% CI: -0.62 to 4.38, P=0.14) or exercise (MD=0.19, 95% CI: -0.99 to 1.37, P=0.75). TENS therapy did not improve the PPT score (MD=0.96, 95% CI: -0.72 to 2.64, P=0.26).
Conclusion: The published evidence for the treatment of MPS by TENS has been reviewed. TENS can be utilized as an adjuvant treatment to help alleviate MPS but should not be regarded as a monotherapy.