Degradation of postural control with aging

Aging negatively impacts the ability to maintain postural stability due to degraded control systems. The entropic half-life, a non-linear variable that quantifies the transition of sample entropy with increasing time scales, quantifies the time that elapses before old positional information no longer influences, or is no longer related to, the control mechanisms that regulate the movement at the current center of pressure location. The entropic half-life provides a more representative and comprehendible way of detecting changes in complexity using measurement units of time. The purpose of this study was to determine the effects of aging on the magnitude and temporal structure of the center of pressure movement during quiet single-limb stance. Center of pressure data of 24 older and 24 younger subjects were analyzed. The complexity of the temporal structure of the center of pressure signal was quantified by calculating the entropic half-life of the center of pressure in the medio-lateral and anterior–posterior directions. The magnitude of movement was quantified using excursion of the center of pressure in the medio-lateral and anterior–posterior directions, the path length, and the 95% ellipse area of the center of pressure. The older subjects demonstrated a significantly shorter entropic half-life for the center of pressure in the anterior–posterior direction (p < 0.001), longer excursions of the center of pressure in the medio-lateral (p < 0.001) and...
Source: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine - Category: Biomedical Engineering Authors: Tags: Original Articles Source Type: research