Real-time motion analysis using CCD camera

Abstract

This paper proposes a device that simultaneously computes and displays the biomechanical quantities, such as joint moments, joint forces and the center of gravity point, at the same time with the symmetric motion of subjects with respect to a sagittal plane. These biomechanical quantities are computed in real-time based on the inverse dynamics, using the marker positions obtained by real-time image processing of the body movement which is captured by a CCD camera. Then these biomechanical quantities are displayed in real-time on a screen by a LCD projector, and accordingly the subject can objectively recognize the quality of the motion by seeing these physical quantities during the motion. In the application of this real-time motion analyzer to the analysis of bow motion, bending and stretching and sit-to-stand motion, it is shown that this device is advantageous for the coaching and the self-education of an optimal motion based on the body mechanics.