The present study investigated the adaptations of specific power bursts during the combined contexts of the proximity (lead vs. trail limb) and height of an obstruction in relation to limb elevation versus progression. Ten young, adult, male subjects walked at their natural speed during unobstructed walking and the bilateral avoidance of moderate and high obstacles. Hip flexor generation power was unaffected by obstacle height for the leading limb and always delayed for the trailing limb. The knee extensor absorption power burst at toe-off was also eliminated for the trailing limb and was found to reappear in mid-swing. Few differences were seen for ankle push-off power. The results suggest that the hip joint is dedicated to limb advancement only, while the knee joint is directly involved in limb elevation and the control of multiarticular effects.
The authors are with the Centre for Interdisciplinary Research in Rehabilitation and Social Integration, 525 Hamel, Quebec, Quebec, Canada, G1M 1S8A. In addition, A.E.S. Niang is with the Sherbrooke University Geriatric Institute, Sherbrooke, and B.J. McFadyen is with the Rehabilitation Department at Laval University, Québec, Canada.