1. Department of Orthopaedic Surgery, Sapporo Medical University School of Medicine, South-1, West-16, Chuo-ku, Sapporo 060–8543, Japan.
2. Department of Physical Therapy, Sapporo Medical University School of Health Sciences, South-3, West-17, Chuo-ku, Sapporo 060–8556, Japan.
3. Department of Human and Mechanical Systems Engineering, Faculty of Engineering, Kanazawa University.