Experimental analysis of force moment about body center of mass during level walking using force plates

In this paper we report the characteristics of force moment about the cente r of mass (COM) of a human body during level walking at a steady pace, usin g two large force plates by which the three-dimensional floor reaction forc e components can be measured. The displacements of the COM in the three dir ections are obtained from the Fourier series of the reaction force componen ts by double integration. The following results are obtained: although the three-dimensional reaction force components are large, the moment of force about the COM becomes very small, which suggests that a human walks produci ng as small a moment as possible about the COM of his/her body. In other wo rds, only a negligible rotation about the COM occurs; the magnitude of the external moment applied at the sole is remarked in the moment of force abou t the vertical axis.