Article

For targeted prevention of falls, it is necessary to identify individuals with
balance impairments. To test the sensitivity of measures of variability, local
stability and orbital stability of trunk kinematics to balance impairments during
gait, we used galvanic vestibular stimulation (GVS) to impair balance in 12 young
adults while walking on a treadmill at different speeds.
Inertial sensors were
used to measure trunk accelerations, from which variability in the medio-lateral
direction and local and orbital stability were calculated.
The short-term
Lyapunov exponent and variability reflected the destabilizing effect of GVS,
while the long-term Lyapunov exponent and Floquet multipliers suggested increased
stability. Therefore, we concluded that only short-term Lyapunov exponents and
variability can be used to asses stability of gait. In addition, to investigate
the feasibility of using these measures in screening for fall risk, the presence
or absence of GVS was predicted with variability and the short-term Lyapunov exponent. Predictions were good at all walking speeds, but best at preferred
walking speed, with a correct classification in 83.3% of the cases.
CI - Copyright (c) 2011 Elsevier B.V. All rights reserved.

Langue : ANGLAIS