The Influence of Aging on Hip Abductor Muscle Torque, Power, Velocity and the Association With Lower Limb Physical Function

Background and purpose: Muscle strength, power, and mass decline with aging, leading to functional loss highly correlated with balance and falls in older adults. Lower limb muscle function is critical for fall prevention in older adults, and hip abductor force and rapid force development have been shown to be important during stepping tasks. However, it remains unclear whether hip abductor muscle function changes with aging. Therefore, the primary aim of this study was to compare maximum torque, submaximal power, and submaximal velocity of hip abductor muscles, as well as hip abductor strength and power clinical assessments, between young and older adults. The secondary aim was to investigate whether there is a relationship between the clinical assessments and hip abduction maximum torque, submaximal power, and submaximal velocity in young and older adults.

Methods: The volunteers young (n = 20, 26.5 ± 3.9) and older (n = 20, 71.9 ± 5.3) adults performed a hip abduction estimated 1-repetition maximum (e1RM) and submaximal tests (40%, 60%, and 70% of e1RM) and clinical assessments (stair climb power test and the 30-second chair stand test).

Results: Older adults exhibited a statistically significant decline in hip abduction torque, power, and velocity, accompanied by lower scores in clinical assessments in comparison to young adults. However, young adults did not exhibit any significant associations between clinical assessments and hip abduction maximum torque, power, and velocity, whereas older adults demonstrated strong correlations (r ≥ 0.52, P ≤ .02).

Discussion: Older adults have a significant reduction in their ability to produce hip abduction torque, power, and velocity, as well as poor performance in clinical assessments compared to young adults. The declines in hip abductor maximum torque, power, and velocity with aging may be related to functional performance, as shown by the significant correlations between these variables and clinical assessments in older adults.

Conclusion: Health care professionals should consider declines in the ability to generate muscle force rapidly, given its significance to lower limb function and overall physical capabilities.