Fourier analysis of vertical forces to integrate balance measurements

Background Balance during orthostatic standing is usually investigated through force platforms and consolidated sets of parameters and protocols [1] based on 51.2s of observation period and on analysis of centre of pressure (COP) movements in the time and in the frequency domain. Force instantaneous changes associated to centre of mass vertical oscillations had been scarcely investigated [2], maybe due to inadequate signal quality, even though they may represent an added value to gain knowledge in muscular strategies adopted to maintain balance under pathological conditions. This study aims at assessing a newly arranged force plate to obtain a reliable insight into the vertical force frequency spectrum; two small samples are used to evaluate feasibility and relevance, i. e. a normal active healthy population (controls) and trained athletes.