The effects of scale display of visual feedback on postural control during quiet standing in healthy elderly subjects.
OBJECTIVE
To assess the effects of scale display of visual feedback (VFB) on postural control during quiet standing in healthy elderly subjects.


METHODS
Before and after intervention trials.


METHODS
Medical university bioengineering laboratory.


METHODS
Twelve healthy elderly subjects (mean age, 70.2+/-2.8 y; mean body weight, 65.5+/-4.1 kg; mean height, 163.4+/-6.5 cm).


METHODS
Participants were asked to stand upright as immobile as possible in an eyes-open condition and 3 VFB conditions involving increasing scale displays: 2 to 1 (VFB(2)), 5 to 1 (VFB(5)), and 10 to 1 (VFB(10)). These latter conditions correspond to the ratio between the real displacements of the center of pressure (COP), as measured by the force platform, and their visualization on the monitor screen.


METHODS
COP displacements were recorded using a force platform.


RESULTS
VFB had different effects on the COP displacements depending on the scale display; no significant difference was observed between the VFB(2) and the eyes-open conditions, whereas the VFB(5) and VFB(10) conditions yielded decreased COP displacements relative to the eyes-open condition.


CONCLUSIONS
The effectiveness of the VFB system in improving postural control during quiet standing in elderly subjects depends on the scale display. These findings could have implications in clinical and rehabilitative areas.
Pinsault
Nicolas
N
Laboratoire TIMC-IMAG, Grenoble, France.
Vuillerme
Nicolas
N