Article

In this study, conditions that enable a prosthetic knee flexion strategy in
transfemoral amputee subjects during obstacle avoidance were investigated. This study explored the hip torque principle and the static ground principle as object
avoidance strategies. A prosthetic limb simulator device was used to study the
influence of applied hip torques and static ground friction on the prosthetic
foot trajectory. Inverse dynamics were used to calculate the energy produced by
the hip joint. A two-dimensional forward dynamics model was used to investigate
the relation between obstacle-foot distance and the necessary hip torques
utilized during obstacle avoidance. The study showed that a prosthetic knee
flexion strategy was facilitated by the use of ground friction and by larger
active hip torques. This strategy required more energy produced by the hip
compared to a knee extension strategy. We conclude that when an amputee maintains
enough distance between the distal tip of the foot and the obstacle during
stance, he or she produces sufficiently high, yet feasible, hip torques and uses
static ground friction, the amputee satisfies the conditions for enable stepping
over an obstacle using a knee flexion strategy.
CI - Copyright (c) 2011 IPEM. Published by Elsevier Ltd. All rights reserved.

Langue : ANGLAIS

Tiré à part : OUI