Article

This study presents an analysis of power exertion for lifting the body's centre
of mass (CoM) during rising from a chair. Five healthy young
(21-44 years) and 12
healthy older (70-79 years) subjects performed sit-to-stand (STS) movements while
data were measured with force-plates underneath chair and feet and motion sensors
attached to different locations on the upper and lower trunk. Force-plate-data
were used to determine the timing of STS movements and the vertical power for
lifting the CoM from a sitting to a standing position.
Data of three-dimensional
hybrid motion sensors, consisting of accelerometers, gyroscopes and
earth-magnetic-field sensors, were used to determine vertical accelerations and
power. The comparison of sensor-based estimations of peak power with peak power
calculated from force-plate-data demonstrated fair to excellent linear
relationships for all sensor locations on the trunk. The best approximation of
peak power was obtained by a weighted combination of data measured at different
trunk locations. Results of the older subjects were consistent with those of the
young subjects performing slow, normal and fast STS movements. The presented
approach is relevant for monitoring fall risk and assessment of mobility in older
people. Similar approaches for assessing power may be developed for other
mobility related activities, such as stair walking, or sports related activities such as jumping.
CI - Copyright 2009 Elsevier B.V. All rights reserved.

Langue : ANGLAIS