Novel non-contact and non-attached technique for detecting sports motion

In this study, we propose an effective non-contact and non-attached technique for detecting sports motion by measuring the current, which is approximately of the order of sub-picoamperes, generated because of a change in the capacitance between a given electrode and the human body. An occurrence model is proposed for the electrostatic induction current generated because of a change in the electric potential of the subject's body due to foot motions. We apply the proposed technique to determine the time for which an athlete's foot remains in contact with the ground and off the ground during pitching and batting motions while playing baseball. Thus, we can quantitatively estimate the time for which an athlete's foot is in contact with the ground and off the ground on the basis of the time at which peaks were observed in the waveforms of the electrostatic induction current. (C) 2011 Elsevier Ltd. All rights reserved.