The effects of scale display of visual feedback on postural control during quiet standing in healthy elderly subjects.

摘要

OBJECTIVE: To assess the effects of scale display of visual feedback (VFB) on postural control during quiet standing in healthy elderly subjects. DESIGN: Before and after intervention trials. SETTING: Medical university bioengineering laboratory. PARTICIPANTS: 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). INTERVENTION: 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. MAIN OUTCOME MEASURE: 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.