1. Department of Orthopedic Surgery, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi 755‑8505, Japan
2. Department of Mechanical Engineering, Yamaguchi University, Ube, Yamaguchi 755‑8611, Japan
3. Non‑Profit Organization Corporation Japan Orthopedic Biomechanics Institute, Hofu, Yamaguchi 747‑0814, Japan
4. Department of Mechanical and Electrical Engineering, National Institute of Technology Tokuyama College, Shunan, Yamaguchi 745‑8585, Japan