Age-related changes in gait velocity and leg extension power in middle-aged and elderly people.

To prevent a decline in gait with age, it is necessary to investigate age-related changes in gait performance and detect related factors. The purpose of this study was to assess the association between gait ability and leg extension power among middle-aged and elderly people. Height, weight, maximum gait velocity (MGV) and leg extension power (LEP) were measured in 752 males and females who participated in the National Institute for Longevity Sciences, Longitudinal Study of Aging (NILS-LSA). Age-related changes in MGV and LEP and the association between MGV and LEP were assessed. There were significant decline trends in height, weight, MGV and LEP with advancing age (p < 0.001). MGV showed a significantly positive correlation with LEP (in males: r = 0.48 p < 0.001, in females: r = 0.47; p < 0.001). Subjects aged 60 yrs and over showed a significantly higher correlation than those under 60 yrs in males, but not in females, after adjustment for height and weight. Although the relationships between MGV and LEP were different by age and gender, LEP may be one of the important factors in maintaining gait ability.