Background: Trigger points in the posterior neck muscles are the outcomes of most common types of musculoskeletal disorders. This study aimed to compare the effects of action potential (AP) simulation and vibration in reducing neck and shoulder pain and disability in subjects with trigger points in the trapezius and levator scapulae muscles.

Materials and Methods: In this single-blinded randomized controlled trial, 30 patients with trigger points in upper trapezius and levator scapula muscles were randomly assigned into two equal groups. In the vibration group, moderate pressure-low frequency vibration was used for 25 minutes and in the AP group, the simulated AP with an intensity of 1mA was applied for 16 minutes. Before and after the treatment, neck disability was assessed using neck disability index neck pain using visual analogue scale shoulder pain and disability using pain and disability index and the ROM using a goniometer. A 16-session therapeutic plan was performed for both groups.

Results: Visual analogue scale was decreased from 7±2.07 to 2±1.13 in the vibration group and from 7.13±1.95 to 2.12±1.06 in the APS group neck disability index was decreased from 26.66±2.56 to 15.33±1.88 in the vibration group and from 26.06±1.83 to 15.06±1.94 in the APS group (P<0.0001). There was no significant difference between the two groups regarding the total variables of the study.

Conclusion: In participants of the study, both vibration and simulated AP not only can decrease the pain and disability in neck and shoulder, but also increase the ROM in the neck.