• disability;
  • skeletal muscle strength;
  • contraction velocity;
  • aging;
  • exercise

Objectives: To explore the relationship between impairment (skeletal muscle strength and contraction velocity) and function in community-dwelling older adults.

Design: Cross-sectional.

Setting: University-based human physiology laboratory.

Participants: One hundred one men and women (aged 75–90).

Measurements: Muscle strength and contraction velocity during bilateral leg press (LP) were calculated during one-repetition maximum (1RM) and 40% 1RM. A short physical performance battery (SPPB) and gait speed (GS) from a 400-m self-paced walk assessed function. Sex differences in LP strength and contraction velocity (at 40% 1RM) were assessed. The relationship between these variables and function was also examined.

Results: Lower extremity strength and contraction velocity were significantly associated with GS (P=.02 and P=.005, respectively) and SPPB (P<.001 and P=.009, respectively) in men only. Contraction velocity, but not muscle strength, was significantly associated with GS (P<.001) and SPPB (P=.02) in women.

Conclusion: Sex differences exist in the relationship between impairment (muscle strength and contraction velocity) and function. Older men and women may employ different strategies to achieve success on different functional tasks. These findings may have important implications for clinicians practicing geriatric rehabilitation.