1. Department of Rehabilitation, The Sakakibara Heart Institute of Okayama: 2-5-1 Nakaichou, Kita-ku, Okayama-shi, Okayama 700-0804, Japan
2. Department of Rehabilitation, Aichi Medical University Hospital, Japan
3. Department of Cardiovascular Surgery, The Sakakibara Heart Institute of Okayama, Japan
4. Department of Physical Therapy, School of Rehabilitation, Hyogo University of Health Sciences, Japan
5. Department of Physical Therapy, School of Health Sciences, Tokyo University of Technology, Japan