Summary

Once again it has been shown, by Collins and Deluca, that the stabilometric signal contains two kinds of information that could be distinguished by an artifice of calculation: information about the movements of the center of pressure and information about the movements of the center of gravity.

The analysis used by Collins and Deluca (analysis of diffusion of the stabilogram) puts forwards new stabilometric parameters to characterize these two types of informations: the diffusion coefficients. But an experimental study of these parameters shows that they are either too poorly sensitive, or too strongly correlated to conventional stabilometric parameters to be useful.

This study underlines that the parameter of length of the statokinesigram remains the best measure of the «dance» of the center of pressure.

Bibliographie

A.F.P. (1985) Normes 85. Éditées par l'Association Française de Posturologie, 4, avenue de Corbéra, 75012 Paris.

Collins J.J., De Luca C.J. (1993) Open-loop and closed-loop control of posture: a random-walk analysis of center-of-pressure trajectories. Exp. Brain Res., 95, 308-18.

Gagey P.M., Bizzo G., Debruille O., Lacroix D. (1985) The one hertz phenomenon. In: Igarashi M., Black F.O. (Eds) Vestibular and visual control on posture and locomotor equilibrium. Karger, Basel, 89-92.

Gagey P.M., Weber B. (1995) Posturologie; Régulation et dérèglements de la station debout. Masson, Paris.

Gurfinkel V.S. (1973) Physical foundations of stabilography. Agressologie, 14, C : 9-14.

(Remerciements à la société Rhône-Poulenc qui a financé en partie ce travail.)