Article

The goal of this study was to investigate adaptation to walking with bilateral
ankle-foot exoskeletons with kinematic control that assisted ankle extension
during push-off. We hypothesized that subjects would show a neuromotor and
metabolic adaptation during a 24min walking trial with a powered exoskeleton.
Nine female subjects walked on a treadmill at 1.36+/-0.04ms(-1) during 24min with
a powered exoskeleton and 4min with an unpowered exoskeleton. Subjects showed a
metabolic adaptation after 18.5+/-5.0min, followed by an adapted period.
Metabolic cost, electromyography and kinematics were compared between the
unpowered condition, the beginning of the adaptation and the adapted period. In
the beginning of the adaptation (4min), a reduction in metabolic cost of 9% was
found compared to the unpowered condition. This reduction was accompanied by
reduced muscular activity in the plantarflexor muscles, as the powered
exoskeleton delivered part of the necessary ankle extension moment. During the
adaptation this metabolic reduction further increased to 16%, notwithstanding a
constant exoskeleton assistance. This increased reduction is the result of a
neuromotor adaptation in which subjects adapt to walking with the exoskeleton,
thereby reducing muscular activity in all leg muscles. Because of the fast
adaptation and the significant reductions in metabolic cost we want to highlight
the potential of an ankle-foot exoskeleton with kinematic control that assists
ankle extension during push-off.
CI - Copyright (c) 2013 Elsevier B.V. All rights reserved.

Langue : ANGLAIS