1. Division of Rehabilitation Medicine, Hokkaido Medical Center for Child Health and Rehabilitation: 1240-6 Kanayama 1, Teine-ku, Sapporo, Hokkaido 006-0041, Japan
2. Department of Physical Therapy, Graduate School of Health Science, Sapporo Medical University, Japan
3. Department of Rehabilitation for the Movement Functions, Research Institute of National Rehabilitation Center for the Disabled, Japan
4. Department of Physical Therapy, Faculty of Human Science, Hokkaido Bunkyo University, Japan