Aging Alters Joint Power Generation across a Range of Gait Speeds in Healthy Elderly

Abstract

There is no general consensus as to why gait dysfunctions (e.g. slower speed, shorter steps, increased cadence) emerge in healthy older adults (OLD). Although previous work has shown that OLD move joint power generation toward the hip and the knee joints, these investigations have not controlled or matched speed, so the changes observed may not be due to aging. The aim of this investigation was to conduct a rigorous and systematic investigation of lower limb joint power in OLD, compared to young adults (YG), when walking at matched speeds. Six older adults (67 ± 5 years) and 6 young adults (26 ± 3 years) participated in this study. The participants’ walking speed was controlled for speeds of 1.0, 1.3 and 1.6 m(s^− 1. No significant group differences were found for gait speed and cadence across speeds conditions. In addition, speed variation within each condition fell below 0.05 m s^− 1. OLD generated significantly less A2 power at all speeds than the YG (p<0.05). This difference was greater at 1.6 m s^− 1. OLD generated significantly greater H3 power at all speeds than YG (p<0.05). K3 power generation during terminal stance was significantly greater in the OLD (p<0.05). The results show that OLD, compared to YG, move power generation away from the ankle toward the hip and the knee joints. These findings show that these gait adaptations are not related to gait speed but are due to aging.