1. Department of Orthopaedic Surgery, Faculty of Medicine, University of Tsukuba, Japan
2. Center for Sports Medicine and Health Science, University of Tsukuba Hospital, Japan
3. Department of Orthopaedic Surgery, Ibaraki Prefectural University of Health Sciences Hospital, Japan
4. Faculty of Medicine, University of Tsukuba, Japan
5. Graduate School of Comprehensive Human Sciences, University of Tsukuba, Japan