1. Department of Mechanical Engineering, Keio University, Yokohama, Kanagawa, Japan;
2. Sakura-ku, starDyna, Saitama, Saitama, Japan;
3. Department of Orthopaedics, Japan Community Health Care Organization, Tokyo Shinjuku Medical Center, Tokyo, Japan;
4. Department of Mechanical and Environmental Informatics, Tokyo Institute of Technology, Meguro-ku, Tokyo, Japan