1. Department of Physical Medicine and Rehabilitation, Shuang Ho Hospital, Taipei Medical University, Taipei, Taiwan;
2. Department of Physical Medicine and Rehabilitation, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan;
3. Graduate Institute of Injury Prevention and Control, Taipei Medical University, Taipei, Taiwan;
4. Department of Physical Medicine and Rehabilitation, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan;
5. Department of Rehabilitation and Movement Science, College of Nursing and Health Sciences, University of Vermont, Burlington, VT, USA;
6. Swiss Paraplegic Research, Nottwil, Switzerland