Muscle activation and fatigue patterns of the gluteus medius and tensor fasciae latae during unilateral hip abduction and lunge exercises

Abstract

Problem Statement: This study aimed to evaluate the myoelectric activation of the gluteus medius (Gmed) and tensor fasciae latae (TFL), and to investigate the occurrence of cross-fatigue during lunge and standing hip abduction (ABD) exercises performed with cable resistance using a crossover machine. Materials and Methods: Ten physically active young men participated in three experimental sessions, each separated by 48 h. The first session involved anthropometric assessment and familiarization with the exercise protocols. During the second session, 10-repetition maximum (10RM) tests were performed for both exercises. In the third session, electromyographic (EMG) recordings of the Gmed and TFL were obtained bilaterally during maximum voluntary isometric contraction (MVIC) tests and during the performance of both exercises at 80% of the 10RM. Data normality was assessed using the Shapiro–Wilk test, and non-parametric comparisons were performed using the Friedman test. Post-hoc analyses for statistically significant differences (p < 0.05) were performed using Dunn's test for multiple comparisons. Effect sizes (Cohen's d) with 95% confidence intervals (95% CI) were calculated using the Estimation Stats platform. All statistical analyses were performed with GraphPad Prism software (version 8.4.3). Results: The findings showed no evidence of cross-fatigue in either the Gmed or TFL following both exercises. Bilateral Gmed activation during the ABD exercise was statistically similar and comparable to the dominant (DOM) limb during the lunge; however, both were significantly greater than the non-DOM (N-DOM) limb activation during the lunge. The TFL exhibited significantly higher activation during ABD compared with the lunge, although no interlimb differences were observed in either exercise. Additionally, the lunge elicited a significantly higher Gmed:TFL activation ratio than the ABD exercise. These results may guide exercise selection in training and rehabilitation programs aiming to preferentially recruit the Gmed during unilateral lower-limb exercises.