1. Department of Physical Medicine and Rehabilitation, Virginia Commonwealth University, Richmond, VA, USA
2. Department of Biostatistics, Virginia Commonwealth University, Richmond, VA, USA
3. Moss Rehabilitation Research Institute, Elkins Park, PA, USA
4. Department of Physical Medicine and Rehabilitation, The Ohio State University, Columbus, OH, USA
5. Mount Sinai School of Medicine, Department of Rehabilitation Medicine, New York, NY, USA