Speed Effect on Joint Powers in Aging Gait

Ankle plantar flexor (A2), hip extensor (H1) and hip flexor (H3) joint power generation are important factors in human gait. It is well known gait speed and ageing alters joint kinetics during walking. Ageing gait has been associated with decreased ankle joint function and increased hip muscle activity. However, it is not known whether this effect of speed upon join kinetics is the same for older and young adults. This study investigated the effect of speed on A2, H1 and H3 joint powers in a group of young (YG) and older adults (OG) walking over a range of speeds. Participants walked at seven speed conditions. Peak joint powers were calculated and regressed as a function of gait speed. All joint powers were affected by speed. The OG increased H3 more than the YG, whereas the YG increased more A2 than the OG. At speeds over 1.5 ms-1 the OG increased cadence more than the YG, whereas the YG increased step length more than the OG. This shows that the OG relied more on hip flexor muscles and increases in cadence to reach a maximum walking speed