An application of mathematical models in posturography

The measurement of the horizontal displacements (HD) of the centre of mass of the human body when standing still, is often performed by means of a platform. The resulting measured HD as a function of time, both in the left-right or sinister-dexter and the posterior-anterior direction, are known as stabilograms. Such stabilograms are being more widely used to obtain the so called measured statokinesigram, similar to a Lissajous-figure, by eliminating time from the sinister-dexter stabilogram and the posterior-anterior stabilogram. It is shown that in using mathematical models of the standing person to obtained the stabilograms, the resulting statokinesigram is very different from the measured statokinesigram. It is also shown that the quantity line-integral calculated from a statokinesigram is much smaller when determined from a statokinesigram corrected by means of the mathematical models.