Extraction of traditional COP-based features from COM sway in postural stability evaluation.

Postural control during quiet standing is evaluated by analyzing CoP sway, easily measured using a force platform. However, recent proliferation of motion tracking systems made easily available an estimate of the CoM location. Traditional CoP-based measures presented in literature provide information about age-related changes in postural stability and fall risk. We investigated, on an age-matched group of subjects, the relationship between classical CoP-based measures computed on sway path and statistical mechanics parameters on diffusion plot, with those extracted from CoM time-series. Our purpose is to understand which of these parameters, computed on CoM sway, can discriminate postural abnormalities, in order to use a video tracking system to evaluate balance in addition to motor capabilities.