Comparative efficacy of repetitive peripheral magnetic stimulation and transcutaneous electrical nerve stimulation in upper trapezius myofascial pain syndrome

Background/aim: In this prospective, randomized, single-blind study, the effects of repetitive peripheral magnetic stimulation (rPMS) and transcutaneous electrical nerve stimulation (TENS) on pain intensity, functional status, and tissue elasticity were evaluated in patients with upper trapezius myofascial pain syndrome (MPS). Materials and methods: A total of 75 female patients were randomly allocated to three groups: rPMS, TENS, and sham rPMS. All participants were provided with an exercise program consisting of cervical range-of-motion (ROM), stretching, and strengthening exercises. Outcome measures included pain intensity assessed using the visual analog scale, pressure pain threshold (PPT), the Neck Disability Index, cervical ROM, SF-36 subscale scores, and ultrasound shear-wave elastography. All data were collected and compared before treatment, immediately after treatment, and 1 month after treatment. Results: Both rPMS and TENS significantly reduced pain intensity, increased PPT, and improved functional outcomes compared with the sham rPMS group. However, rPMS was associated with a greater increase in PPT compared with TENS (p = 0.013). A significant improvement in ROM was observed across all three groups for all neck positions, except for extension in the sham rPMS group. The rPMS group showed significant improvements in four SF-36 subscales compared with the sham rPMS group, whereas the TENS group showed no significant differences. Furthermore, improvements in physical functioning (p = 0.011) and mental health (p = 0.007) scores were significantly greater in the rPMS group than in the TENS group. A significant increase in muscle elasticity was observed only in the TENS group; no significant change was observed in the rPMS or sham rPMS groups. Conclusion: The findings may suggest that rPMS may be a promising noninvasive modality for the management of MPS. It may be used to reduce pain and improve functional outcomes in patients with MPS. Elastography findings may indicate that neurophysiological mechanisms contribute substantially to pain and dysfunction; however, mechanical stiffness cannot be excluded as a contributing factor. Longer follow-up studies are needed to determine the effectiveness of rPMS treatment protocols.