Effects of Age and Gender on the Power Generation Capabilities of Lower Limb Muscles in the Elderly

This study aimed to investigate the effects of age and gender on the power generation capabilities of lower limb muscles in the elderly aged from 65 to 79 yrs. In addition to isometric knee extension torque (KT) and leg extension power (LP), mechanical power during movements specific to maximal walking (WP) and running (RP) without arm movements were determined using a non-motorized treadmill in 140 men (71.3±4.0 yrs, mean±SD) and 172 women (70.2±3.7 yrs). The measured variables were expressed as relative to body mass and then their percentages to mean values for the subjects aged 65 to 69 yrs of men and women, respectively, were calculated. The percentages of all measured variables except for KT in the women were negatively correlated to age in both men (r=-0.207 to -0.375, p<0.05) and women (r=-0.228 to -0.263, p<0.05). In the slope of regression line for the relationship between age and the percentage for each of LP, WP, and RP, no significant differences were found between the men and women and between the variables. In the sub-sample of the subjects, adjusted by their body height and mass, the men (n=31) showed significantly higher values than the women (n=34) in all variables except for WP, with a greater relative difference in LP and RP than in KT. The findings obtained here indicate that, at least in the elderly aged from 65 to 79 yrs, 1) the rate of age-related loss in the power generation capability of lower limb muscles is independent of gender and movement patterns, and 2) power development in the movement form of maximal walking is less influenced by gender as compared to that of maximal running as well as knee extension torque and leg extension power.