Article

The study of postural control processes during locomotion may provide useful
outcome measures of stability for people with unilateral vestibular hypofunction
(UVH). Since nonlinear analysis techniques can characterize complex behaviour of
a system, this may highlight mechanisms underlying dynamic stability in
locomotion, although only few efforts have been made. In particular, there have
been no studies that use recurrence quantification analysis (RQA), which can be
applied even to short and non-stationary data. The purpose of this study was to
develop a new method for walking balance assessment measuring the complexity of
head, trunk and pelvis three-dimensional accelerations and angular velocities
during normal overground locomotion by means of RQA in normal subjects and UVH
patients. The results showed differential effect of upper body parts on pattern
regularity, with better head than pelvis stabilization in both groups of
subjects. The RQA outputs such as percent determinism and recurrence were
nevertheless significantly lower in the UVH group for all measures, suggesting
that body accelerations and angular velocities, although not significantly
different in amplitude, were more chaotic in patients. The observed lower
regularity of upper body movements in UVH is consistent with an important role of
the vestibular system in controlling dynamic stability during walking. The
findings suggest that RQA can be used as a quantitative tool to assess walking
performance and rehabilitation outcome in patients with different balance
disorders.
CI - Copyright (c) 2011 Elsevier B.V. All rights reserved.

Langue : ANGLAIS