Article

It has frequently been proposed that lowering walking speed is a strategy to
enhance gait stability and to decrease the probability of falling. However,
previous studies have not been able to establish a clear relation between walking
speed and gait stability. We investigated whether people do indeed lower walking
speed when gait stability is challenged, and whether this reduces the probability
of falling. Nine healthy subjects walked on the Computer Assisted Rehabilitation
ENvironment (CAREN) system, while quasi-random medio-lateral translations of the
walking surface were imposed at four different intensities. A self-paced
treadmill setting allowed subjects to regulate their walking speed throughout the
trials. Walking speed, step length, step frequency, step width, local dynamic
stability (LDS), and margins of stability (MoS) were measured. Subjects did not
change walking speed in response to the balance perturbations (p=0.118), but made
shorter, faster, and wider steps (p<0.01) with increasing perturbation intensity.
Subjects became locally less stable in response to the perturbations (p<0.01),
but increased their MoS in medio-lateral (p<0.01) and backward (p<0.01)
direction. In conclusion, not a lower walking speed, but a combination of
decreased step length and increased step frequency and step width seems to be the
strategy of choice to cope with medio-lateral balance perturbations, which
increases MoS and thus decreases the risk of falling.
CI - Copyright (c) 2012 Elsevier B.V. All rights reserved.

Langue : ANGLAIS