Comparison of gluteus maximus subdivisions, erector spinae, and biceps femoris activities and lumbopelvic motion during various prone hip exercises

BackgroundPrevious studies have reported that the gluteus maximus (GMax) consists of two distinct functional portions: the upper or superficial portion (GMU) and the lower or deep portion (GML). However, there is a lack of current literature providing recommendations for effective functional exercises that specifically target each subdivision of the GMax.ObjectiveTo investigate differences in GMax subdivisions, erector spinae (ES), and biceps femoris (BF) electromyographic (EMG) activity and lumbopelvic motion during five prone hip extension (PHE) exercises.MethodsThis cross-sectional study recruited 38 asymptomatic young adults. Participants performed five PHE exercises: PHE with knee extension (PHEKE), PHE with 90° knee flexion (PHRKF) and hip abduction 0° (PHEKFA0), 15° (PHEKFA15), 30° (PHEKFA30), and PHEKF with trunk support on the table (PHEKFTS). Surface EMG signals were recorded from GMU, GML, ES, and BF on the dominant side and the angles of pelvic were measured during the exercises, which involved an abdominal drawing-in maneuver. Differences in EMG amplitude and pelvic motion among the five conditions were analyzed using one-way repeated measures analysis of variance (ANOVA). For significant main effects, pairwise comparisons were conducted with Bonferroni correction to identify specific differences between conditions (0.05/10). The level of statistical significance was set at p <0.005.ResultsGMU and GML EMG amplitudes showed similar trends across the five PHE exercises. The highest EMG amplitudes for GMU and GML were observed in the PHEKFTS exercise. Additionally, the GMU and GML EMG amplitudes were significantly greater in PHEKFA30 compared to PHEKFA15 and PHEKFA0 (p < 0.005). Muscle activation of ES was significantly higher in PHEKFA30 compared to PHEKE exercises showed significant differences (p < 0.005). Muscle activation of BF and BF/Gmax ratio were significantly higher in PHEKE compared to all other PHE exercises (p < 0.005).ConclusionClinically, PHEKFA30 is recommended for effectively activating GMU and GML while minimizing compensation from BF, and managing lumbopelvic motions. For advanced GMax rehabilitation, PHEKFTS is suggested due to its favourable ratio of ES to GMax.