Article

Partial body weight-supported treadmill training is an approach for gait
rehabilitation. Variables such as stepping frequency and the amount of body
weight support are key parameters manipulated during training. The purpose of
this study was to quantify the extent to which body weight support and stride
frequency contribute and interact to produce the coordination patterns of the leg
muscles. Principal components analysis was used to provide insight into the
interaction effects of these factors on electromyographical (EMG) activity during
treadmill locomotion. Eight healthy subjects walked on a treadmill at 15
different combinations of weight support (0%, 20%, 40%, 60%, 100%), and stride
frequency (0.40, 0.49, 0.57 Hz). Treadmill walking was performed with the Lokomat
robotic gait orthosis to constrain leg kinematics. Surface EMG data were
collected from several lower limb muscles. Results indicate that much of the
variance in EMG activity during treadmill locomotion can be attributed to the
mechanics of the locomotor task imposed by the level of body weight support and
stride frequency. We also showed that body weight support and stride frequency
interact in different ways to affect muscle coordination patterns. EMG
coordination patterns are similar between conditions of high levels of body
weight support and faster stride frequencies vs. lower levels of body weight
support and slower stride frequency. Our data suggest that the interaction of
body weight support and stride frequency should be taken into consideration for
optimizing motor output during locomotor training.
CI - Copyright 2010 Elsevier B.V. All rights reserved.

Langue : ANGLAIS