Article

Ankle-foot orthoses (AFOs) can improve gait in patients with hemiplegia. However,
it is anecdotally known that excessive plantarflexion resistance of an AFO could
induce undesired knee flexion at early stance. The aim of this study was to
systematically investigate the effect of varying the degrees of plantarflexion
resistance of an AFO on knee flexion angles at early stance in five subjects with
chronic stroke who demonstrated two clear knee flexion peaks at early stance and
swing. Each subject wore an experimental AFO constructed with an oil-damper type
ankle joint and was instructed to walk at their self-selected walking speed under
five plantarflexion resistance conditions. The sagittal plane ankle and knee
joint kinematics and gait speed were analyzed using a 3-D Motion Analysis System.
A number of significant differences (P<0.005) in maximum knee flexion angles at
early stance amongst different plantarflexion resistance conditions were
revealed. The knee flexion angle was 23.80 (3.25) degrees under the free hinge
joint condition (condition 1), while that was 26.09 (3.79) degrees under the
largest resistance condition (condition 5). It was therefore demonstrated that
increasing the plantarflexion resistance of an AFO would induce more knee flexion
at early stance phase in patients with stroke.
CI - Copyright (c) 2012 Elsevier B.V. All rights reserved.

Langue : ANGLAIS