Rodrigues Rodrigo, Sonda Francesca Chaida, Frigotto Michele Fernandes, Gaviraghi Pablo, Molinari Talita, Pereira Nicolas da Silva, Marques Matheus Iglesias, Guimarães Rodrigo Freire, Cabral Eduarda Bastos, Rabello Rodrigo
Graduate Program in Health Science, Federal University of Rio Grande, Rio Grande, Brazil.
Sports and Exercise Neuromechanics Group, Federal University of Rio Grande, Rio Grande, Brazil.
PLoS One. 2025 Sep 8;20(9):e0331553. doi: 10.1371/journal.pone.0331553. eCollection 2025.
Single-leg stance requires pelvic stability, largely supported by the hip abductors. Differences in hip abductor activation between sexes and individuals with or without musculoskeletal conditions may relate to abductor weakness. However, the relationship between hip abduction strength and muscle activation during stance, and whether this is moderated by sex, remains unclear.
To investigate whether maximal hip abduction strength is associated with hip abductor EMG amplitude during single-leg stance, considering sex as a moderator.
Thirty-six adults (18 males, 18 females) performed an estimated 1RM side-lying hip abduction test and two 10-second single-leg stance trials. EMG amplitude of the gluteus medius (GMed) and tensor fasciae latae (TFL) was analyzed. A moderation analysis (PROCESS Model 1) was used to test the interaction between strength and sex.
Hip abduction strength, sex, and their interaction explained 51% of the variance in GMed EMG amplitude (R2 = 0.51; p < 0.001). A significant strength × sex interaction were observed (p = 0.002). Females with lower strength showed greater GMed activation (p < 0.001); this was not seen in males (p = 0.24). No significant effects were found for TFL activation (R2 = 0.02; p = 0.89).
Females with lower hip abduction strength demonstrate greater GMed activation during single-leg stance, suggesting a sex-specific compensatory strategy. No similar effect was observed for TFL. These findings highlight the importance of considering sex in neuromuscular assessments of pelvic stability.
单腿站立需要骨盆稳定，这在很大程度上由髋外展肌支撑。性别以及有无肌肉骨骼疾病的个体之间髋外展肌激活的差异可能与外展肌无力有关。然而，站立期间髋外展力量与肌肉激活之间的关系，以及这种关系是否受性别影响，仍不清楚。
以性别作为调节变量，研究最大髋外展力量与单腿站立期间髋外展肌肌电图（EMG）幅度是否相关。
36名成年人（18名男性，18名女性）进行了估计的1次重复最大量（1RM）侧卧位髋外展测试以及两次10秒的单腿站立试验。分析了臀中肌（GMed）和阔筋膜张肌（TFL）的EMG幅度。采用调节分析（PROCESS模型1）来检验力量与性别的交互作用。
髋外展力量、性别及其交互作用解释了GMed EMG幅度51%的变异（R2 = 0.51；p < 0.001）。观察到显著的力量×性别交互作用（p = 0.002）。力量较低的女性表现出更大的GMed激活（p < 0.001）；男性中未观察到这种情况（p = 0.24）。未发现TFL激活有显著影响（R2 = 0.02；p = 0.89）。
髋外展力量较低的女性在单腿站立期间表现出更大的GMed激活，提示存在性别特异性的代偿策略。TFL未观察到类似效应。这些发现凸显了在骨盆稳定性的神经肌肉评估中考虑性别的重要性。
