Electrical muscle stimulation towards self-physiotherapy on myofascial pain syndrome

Myofascial trigger points (MTrPs) are the cause of pain from myofascial pain syndrome (MPS), frequently in the trapezius muscle (TM). Working adults often avoid treatment due to the need for therapist assistance and limited time.

This study aimed to investigate whether electrical muscle stimulation (EMS) and active stretching (AS) can be used as a method for the self-physiotherapy of MTrPs in the TM, and to evaluate the effectiveness of the EMS + AS technique, which resembles a therapist's resistance in passive stretching (PS). Two experimental studies were conducted: Experiment 1 (8 adults with MPS) assessed TM changes via ultrasound imaging, and Experiment 2 (65 adults with MPS) examined changes in pain intensity (PI), pressure pain threshold (PPT), and surface electromyography (sEMG) activity, along with participants' feedback. A one-minute treatment duration was delivered for each of condition in random order.

Experiment 1 suggests a possible trend that EMS + AS produces consistent reductions in TM thickness over 10 s; however, no significant differences were observed between time points or treatments (p > 0.05). Experiment 2 showed that EMS + AS significantly reduced PI compared with PS (17.50% difference, p = 0.047). Participant feedback showed a significant preference for EMS + AS over PS (51.40% difference, p = 0.002). Participants with prior stretching experience were 5.11 times more prone to correctly identify both exercise types as beneficial (OR = 5.11, p = 0.014).

EMS + AS is a practical self-physiotherapy approach that does not require therapist intervention, as objective physiological outcomes did not differ significantly between therapies and the method can be conveniently performed in office or home settings.