Effectiveness of Repetitive Peripheral Magnetic Stimulation (rPMS) in Relieving Post-Needling Soreness in Patient with Upper Trapezius Myofascial Pain Syndrome: A Double-Blind, Randomized Clinical Trial.

Objective: To study the effectiveness of relieving post-needling soreness with repetitive peripheral magnetic stimulation (rPMS) compared with sham.

Methods: This double-blind, randomized clinical trial evaluated the effects of repetitive peripheral magnetic stimulation (rPMS) on post-needling soreness following dry-needling treatment. Participants who had active myofascial pain trigger points (MTrPs), in the upper trapezius muscle and received dry needling at the upper trapezius muscle were randomly assigned to either an rPMS group, which received targeted magnetic stimulation at the site of post-needling soreness, or a sham group, which receiving a placebo intervention simulating the rPMS procedure. The rPMS parameters were set to standard mode with normal current direction and a biphasic waveform. Specific settings included an inter-pulse interval of 10, burst pulse of 2, pulse B/A ratio of 1.0, a repetitive rate of 20 pulses per second, and a total of 20 pulse trains over a 10-minute session. Results were assessed using a standardized pain scale to quantify soreness levels at various intervals post-treatment, ultimately aiming to determine if rPMS significantly enhances recovery compared to sham stimulation of magnetic stimulation sessions at the sore area or a sham group undergoing a placebo intervention mimicking the rPMS procedure. The primary outcome was the pressure pain threshold (PPT) change, measured immediately after dry needling and post-intervention. Secondary outcomes included changes in pain intensity, assessed using the Numeric Rating Scale (NRS) immediately post-dry needling, post-intervention, and at 24- and 48-hours post-intervention, as well as neck range of motion, measured at the same intervals. This methodology provided a robust framework to compare the therapeutic effects of rPMS with a placebo intervention in managing post-needling soreness.

Results: The rPMS group demonstrated a significant increase in PPT compared to the sham group (P=0.002). The Numeric Rating Scale (NRS) also significantly improved in the rPMS group compared to the sham group (P < 0.05). No serious adverse events were reported.

Conclusion: Repetitive peripheral magnetic stimulation (rPMS) is an effective method for relieving post-needling soreness compared to sham treatment. This non-invasive modality may benefit clinical practice by enhancing patient comfort and recovery after needling interventions.