An Analysis of Characteristics of Normal Walking Using a Large Forceplate : 1st Report, The Characteristics of the Antero-posterior Step Forces

Abstract

Periodic step forces which were obtained from a large force plate were expanded in Fourier series. The relative velocities and the relative displacements of the center of gravity of a human body were obtained by integrating those Fourier series. It was emphasized that the walking state diagrams, that is, Lissajous' figures of those step forces, relative velocities and relative displacements were available to analyze the characheristics of waling. The even terms of the Fourier coefficients of antero-posterior step forces were large and implied symmetry of right and left step forces. The odd terms of those were small and implied nonsymmetry of right and left step forces. The ratio of the even-numbered Fourier coefficients to the total amplitudes of the relative velocities of the center of gravity in antero-posterior direction was linear to the walking speed.