1. Department of Occupational Therapy, Sapporo Medical University Hospital, Japan
2. Department of Occupational Therapy, Faculty of Human Science, Hokkaido Bunkyo University: 5-196-1 Kogane-chuo, Eniwa 061-1449, Japan
3. Department of Orthopaedic Surgery, Saisei-kai Otaru Hospital, Japan
4. Department of Orthopaedic Surgery, Sapporo Medical University School of Medicine, Japan
5. Department of Public Health, Sapporo Medical University School of Medicine, Japan