Age-related changes in the range and velocity of postural sway.

The aim of this analysis was to compare values of centre of pressure (CoP) measures, which describe the ability to maintain static body balance (range of body sway and velocity in antero-posterior and medio-lateral directions), in two age groups on the basis of a systematic review and meta-analysis of available data published worldwide. After a systematic review of publications presenting values of selected CoP measures, a numerical database with means and standard deviations was created. Data were classified by eye condition (open or closed) and by age group (18-35 or ≥56). Allocation to each group was based on the mean value of age of each sub-group in the numerical database. The Mann-Whitney U test was used to test the statistical significance of differences between age groups and eyes-open and eyes-closed conditions. This article shows mathematical equations, which quantitatively express increases in body sway and its velocity with age. On the basis of those equations, higher values have been shown for both displacement and velocity measures for the EC vs. the EO conditions and for the elderly vs. the young. The differences between age groups are greater for the velocity measures.