Article

Falls and fall-related injuries cause extremely costly and potentially fatal
health problems in people post-stroke. However, there is no global indicator of
walking instability for detecting which individuals will have increased risk of
falls. The purposes of this study were to directly quantify walking stability in
stroke survivors and neurologically intact controls and to determine which
stability measures would reveal the changes in walking stability following
stroke. This study thus provided an initial step to establish objective measures
for identifying potential fallers. Nine post-stroke individuals and nine controls
walked on a treadmill at four different speeds. We computed short-term local
divergence exponent (LDE) and maximum Floquet multiplier (maxFM) of the trunk
motion, average and variability of dynamic margins of stability (MOS) and step
spatiotemporal measures. Post-stroke individuals demonstrated larger short-term
LDE (p = 0.002) and maxFM (p = 0.041) in the mediolateral (ML) direction compared
to the controls but remained orbitally stable (maxFM < 1). In addition,
post-stroke individuals walked with greater average step width (p = 0.003) but
similar average ML MOS (p = 0.154) compared to the controls. Post-stroke
individuals also exhibited greater variability in all MOS and step measures (all
p < 0.005). Our findings indicate that post-stroke individuals walked with
greater local and orbital instability and gait variability than neurologically
intact controls. The results suggest that short-term LDE of ML trunk motion and
the variability of MOS and step spatiotemporal measures detect the changes in
walking stability associated with stroke. These stability measures may have the
potential for identifying those post-stroke individuals at increased risk of
falls.
CI - Copyright (c) 2014 Elsevier B.V. All rights reserved.

Langue : ANGLAIS