1. L.-J. Kang, PT, PhD, was a doctoral candidate in the Department of Physical Therapy and Rehabilitation Sciences, College of Nursing and Health Professions, Drexel University, Mail Stop 502, 245 N 15th St, Philadelphia, PA 19102-1192 (USA), when this study was completed.
2. R.J. Palisano, PT, ScD, is Professor, Department of Physical Therapy and Rehabilitation Sciences, College of Nursing and Health Professions, Drexel University, and member of the scientific staff, Shriners Hospitals for Children, Philadelphia, Pennsylvania.
3. M.N. Orlin, PT, PhD, is Associate Professor, Department of Physical Therapy and Rehabilitation Sciences, College of Nursing and Health Professions, Drexel University, and member of the scientific staff, Shriners Hospitals for Children, Philadelphia.
4. L.A. Chiarello, PT, PhD, PCS, is Associate Professor, Department of Physical Therapy and Rehabilitation Sciences, College of Nursing and Health Professions, Drexel University, and member of the scientific staff, Shriners Hospitals for Children, Philadelphia.
5. G.A. King, PhD, is Senior Scientist, Bloorview Research Institute, Toronto, Ontario, Canada.
6. M. Polansky, ScD, MSW, is Associate Professor, Department of Epidemiology and Biostatistics, School of Public Health, Drexel University.