Gender specificity in the age-related decline of strength: concentric versus eccentric

Objective: To assess gender specific differences in the decline of quadriceps strength under concentric and eccentric conditions. Design: Sixty volunteer subjects clear of musculoskeletal pathology were gender matched to three age groups (20-29, 40-49, and 60-69) with ten subjects in each gender-age group. Subjects performed concentric and eccentric knee extension at 60° s -1 and 120° s -1 on a Cybex 6000 isokinetic dynamometer. Strength was measured as peak torque (PT) as a percentage of gross body weight. The rate of strength decline between genders at each contraction type and angular velocity was expressed by plotting regression lines and comparing slopes for significant differences. Results: Eleven of twelve inter- and intragender comparisons of strength decline failed to reveal significance with either angular velocity or contraction type (p = 0.09 - 0.97). However, unlike the males, females revealed a more significant rate of decline in eccentric strength than with concentric at 120° s -1 (p < 0.05). Intergender comparison of concentric strength at 120°s -1 was insignificant (p = 0.09). Conclusions: Although there were no significant difference between genders, females displayed a more precipitous rate of decline in eccentric strength than concentric. Furthermore, but statistically insignificant at p = 0.09, males appear to lose concentric strength at a greater rate than do females at the faster angular velocity.