Effects of real-time visual biofeedback of pelvic movement on electromyographic activity of hip muscles and lateral pelvic tilt during unilateral weight-bearing and side-lying hip abduction exercises

Abstract

Although neutral pelvic alignment is important for hip abduction exercises, studies exploring objectively monitored pelvic alignment on the gluteus medius (Gmed) muscle activity during hip abduction exercises, especially under weight-bearing (WB) conditions, are limited. Therefore, we examined the effects of real-time visual biofeedback (RVBF) of pelvic movement on electromyographic (EMG) activity of hip muscles and lateral pelvic tilt during unilateral WB and side-lying hip abductions. Fifteen male participants performed unilateral WB and side-lying hip abduction exercises with and without RVBF. Under the RVBF condition, participants monitored pelvic movements in real time during hip abduction exercises. EMG activity of Gmed and quadratus lumborum (QL) as well as lateral pelvic tilt angle were recorded during each hip abduction exercise. Gmed EMG activity increased, while lateral pelvic tilt decreased during both hip abduction exercises with RVBF (p < 0.05). Additionally, the changes in Gmed activity, the Gmed/QL activity ratio, and the lateral pelvic tilt angle under RVBF were greater during unilateral WB hip abduction than during side-lying hip abduction (p < 0.05). These results suggest that RVBF of pelvic movement could be useful to strengthen Gmed and prevent compensatory lateral pelvic movement during hip abduction exercises, especially in the unilateral WB position.