Article

Body sway is usually described by center of foot pressure (COP)-derived
parameters. Their sensitivity to vertical center of mass (COM) redistribution
below its natural position has not yet been examined during quiet stance tasks.
We examined the effects of both lowering and raising the COM on the following
body sway parameters: cumulative, medial-lateral and anterior-posterior COP
average velocity, amplitude and frequency. For this purpose, 13 healthy male
subjects performed a quiet stance balance task with feet positioned in parallel
stance (PS) at hip width apart and with hands holding a stick across the rear
part of the shoulders. Each subject carried out five different modifications of
the PS task in a randomized order: no additional load, an additional load of 10
kg and 30 kg suspended from the waist at mid-lower leg height, and an additional
load of 10 kg and 30 kg across the rear of the shoulders. The studied body sway
parameters proved to be sensitive to these manipulations. Specifically, lowering
and raising the COM was mirrored in a systematic decrease/increase of the
velocity, amplitude, and frequency parameters, indicating a larger effect in the
anterior-posterior direction. These results suggest that the elevation of the
body COM from a lower to a higher position systematically decreases the postural
control during quiet standing, and consequently, increases the intensity of the
balancing task. Thus, this type of physical manipulation could provide the basis
for a simple progression in functional resistance training for persons with
compromised balance.
CI - Copyright (c) 2011. Published by Elsevier B.V.

Langue : ANGLAIS