Article

The stride before landing may be important during stepping down. The aim of this
study was to analyze variability of the kinematics and muscle activity in the
final stride before stepping down a curb, with and without ankle and knee muscle
fatigue. Ten young participants walked at self-selected speed and stepped down a
height difference (10-cm) in ongoing gait. Five trials were performed before and
after a muscle fatigue protocol (one day: ankle muscle fatigue, another day: knee
muscle fatigue). The analysis focused on the trailing leg during the last but one
and the last step on the higher level. Kinematics and muscle activity were
recorded. Fatigue increased variability of foot-step horizontal distance in the
last step on the higher level of the trailing limb, as well as in the first steps
on the lower level for both limbs. This appeared due to an increase in the range
of motion of the knee joint after both fatigue protocols. Participants
additionally showed an increased ankle and hip ROM and decreased knee ROM. Our
results suggest a loss of control under fatigue reflected in a higher variability
of trailing and leading limb-step horizontal distances, with compensatory changes
to limit fatigue effects, such as a redistribution of movement over joints.
CI - Copyright (c) 2012 Elsevier B.V. All rights reserved.

Langue : ANGLAIS