1. Department of Physical Medicine and Rehabilitation, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania
2. Department of Physical Medicine and Rehabilitation, Michigan State University, East Lansing, Michigan
3. Department of Physical Medicine & Rehabilitation, Vanderbilt University Medical Center, Nashville, Tennessee
4. Department of Physical Medicine & Rehabilitation, University of Utah School of Medicine, Salt Lake City, Utah
5. Department of Rehabilitation and Regenerative Medicine, Columbia University Vagelos College of Physicians and Surgeons, New York, New York, USA