Formulation of human movements by Riemannian distance interpreted in a dynamical sense

A measure called inertia-induced measure was developed by analyzing dynamical and mathematical characteristics of multi-joint movements from the viewpoint of Riemannian distance. The measure provides evaluation of the amount of inertia-induced movement (free motion by inertia, Coriolis, and centrifugal forces) of a multi-joint system. By applying the measure to actual human movements, it was shown that the smooth movements tend to be closer to the inertia-induced movements than the clumsy movements. From this observation, it was suggested that humans coordinate various regions of their body so as to use their own inertia-induced properties efficiently in smooth movements. Based on the results, a motion control method for a multi-joint robot using the inertia-induced effect was designed.