1. Center for Spinal Cord Injury Research and Center for Outcomes and Assessment Research, Kessler Foundation, West Orange, New Jersey, USA
2. Department of Physical Medicine and Rehabilitation, Rutgers New Jersey Medical School, Newark, NJ, USA
3. Department of Rehabilitation and Human Performance, Icahn School of Medicine at Mount Sinai, New York, New York, USA
4. Craig Hospital, Englewood, Colorado, USA
5. Rancho Los Amigos National Rehabilitation Center, Downey, California, USA
6. Case Western Reserve University, Cleveland, Ohio, USA
7. MetroHealth System, Cleveland, OH, USA
8. Human Engineering Research Laboratories, Veterans Affairs Pittsburgh Healthcare System, Pittsburgh, Pennsylvania, USA
9. Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, PA, USA