Rotational components in centre of pressure signals

Static posturography provides an objective assessment of postural control performances by characterizing the body sway during quiet upright standing. The Center-of-Pressure (CoP) signal is recorded by a force platform and then analyzed according to different techniques. Traditional approaches extrapolate geometrical, statistical and spectral parameters from the sway path. In this study we hypothesized that CoP signal shows inherent rotational characteristics. To extract these components we applied the rotary spectra technique and we demonstrated the presence of clockwise and counter-clockwise rotational components in the CoP signal of healthy subjects.