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.