1. Department of Physical Therapy, Faculty of Health Sciences, Hokkaido University of Science, Sapporo 006-8585, Japan
2. Shin-Sapporo Orthopaedic Hospital, Sapporo 004-0051, Japan
3. Division of Rehabilitation Sciences, Graduate School of Health Sciences, Hokkaido University of Science, Sapporo 006-8585, Japan
4. Sapporo Keijinkai Rehabilitation Hospital, Sapporo 060-0010, Japan
5. The Research Center for Advanced Science and Technology, Institute of Gerontology, The University of Tokyo, Tokyo 113-8656, Japan