1. M.D. Lewek, PT, PhD, Division of Physical Therapy, Department of Allied Health Sciences, and Human Movement Science Program, University of North Carolina at Chapel Hill, 3043 Bondurant Hall, CB 7135, Chapel Hill, NC 27599-7135 (USA).
2. J. Feasel, MS, Department of Computer Science, University of North Carolina at Chapel Hill.
3. E. Wentz, PT, Human Movement Science Program, University of North Carolina at Chapel Hill.
4. F.P. Brooks Jr, PhD, Department of Computer Science, University of North Carolina at Chapel Hill.
5. M.C. Whitton, MS, Department of Computer Science, University of North Carolina at Chapel Hill.