Article

The present study introduces a novel instrumented method to characterize postural
movement strategies to maintain balance during stance (ankle and hip strategy),
by means of inertial sensors, positioned on the legs and on the trunk. We
evaluated postural strategies in subjects with 2 types of Parkinsonism:
idiopathic Parkinson's disease (PD) and Progressive Supranuclear Palsy (PSP), and
in age-matched control subjects standing under perturbed conditions implemented
by the Sensory Organization Test (SOT). Coordination between the upper and lower
segments of the body during postural sway was measured using a covariance index
over time, by a sliding-window algorithm. Afterwards, a postural strategy index
was computed. We also measured the amount of postural sway, as adjunctive
information to characterize balance, by the root mean square of the horizontal
trunk acceleration signal (RMS). RESULTS: showed that control subjects were able
to change their postural strategy, whilst PSP and PD subjects persisted in use of
an ankle strategy in all conditions. PD subjects had RMS values similar to
control subjects even without changing postural strategy appropriately, whereas
PSP subjects showed much larger RMS values than controls, resulting in several
falls during the most challenging SOT conditions (5 and 6). Results are in
accordance with the corresponding clinical literature describing postural
behavior in the same kind of subjects. The proposed strategy index, based on the
use of inertial sensors on the upper and lower body segments, is a promising and
unobtrusive tool to characterize postural strategies performed to attain balance.
CI - Copyright (c) 2014 Elsevier B.V. All rights reserved.

Langue : ANGLAIS