Acute effects of handheld percussive massage therapy on various posterior shoulder soft tissue areas in healthy young males

BACKGROUND: Interventions using vibration stimulation can increase the range of motion (ROM) without compromising muscle strength. Handheld percussive massage directly stimulates the focal area. Therefore, its effectiveness may be affected depending on the areas of stimulation. Thus, this study aimed to compare the effects of handheld percussive massage to different stimulation areas on shoulder internal rotation ROM and shoulder external rotation muscle strength and torque. METHODS: This crossover study included 15 healthy male volunteers (20.6±1.5 years). A 5-min percussive massage was applied to three posterior shoulder areas: the muscle belly, proximal muscle-tendon junction, and distal muscle-tendon junction. Internal rotation ROM (vertebral level and abduction position) and external rotation muscle strength (isometric and concentric) were measured before and immediately after the intervention and compared. RESULTS: Internal rotation ROM (vertebral level and abduction position) showed a time effect (P<0.05). No interaction or between-condition effects were observed. Post hoc testing showed a change in internal rotation ROM (vertebral level and abduction position) after intervention at the three stimulation areas (P<0.05). Muscular strength did not show any interaction, time, or between-condition effects. CONCLUSIONS: Handheld percussive massage therapy to various posterior shoulder soft tissue areas increased the internal rotation ROM without decreasing the external rotation maximum voluntary contraction torque.