Decline in hip abductor torque, power, and velocity emerges in middle age: age and sex differences across adulthood

BACKGROUND: The hip abductor muscles are critical for maintaining mediolateral balance and preventing falls, yet age- and sex-related differences across adulthood remain unclear. Objectives: This cross-sectional study examined age- and sex-related differences in hip abductor maximal torque, submaximal power and velocity, and clinical functional outcomes. METHODS: Forty-two adults were included: 14 young (27±4y), 14 middle-aged (51±9y), and 14 older adults (74±6y); 20 male and 22 female. Participants completed hip abductor tests at 10-70% of estimated one-repetition maximum (1RM) and two clinical assessments: the 30-s Chair-Stand and the Stair-Climb Power Tests. MANCOVA was used to evaluate the effects of age and sex on eight power/velocity outcomes, while adjusting for height and weight. Mixed-effects models incorporated the repeated-measures structure across loads. Separate ANCOVAs were conducted to compare age groups for the clinical outcomes. RESULTS: Hip abductor power and velocity were lower with advancing age (p<.001). Sex showed an independent multivariate effect (p=.002), with load-specific male-female differences in power (p=.014). Age effects were significant across all clinical outcomes (p<.001). Younger individuals outperformed middle-aged and older adults in torque and chair stand tests. However, young and middle-aged adults performed similarly and better than older adults on the stair climb test. CONCLUSIONS: Hip abductor torque, power, and velocity differ across age groups, with lower values observed in middle-aged individuals. Sex differences occur mainly in high-load power but not in functional performance. Early evaluation and targeted training of the hip abductors may help preserve physical function across the lifespan.