1. S.C. Dusing, PT, PhD, is Assistant Professor, Department of Physical Therapy, Virginia Commonwealth University, PO Box 980224, Richmond, VA 23298 (USA).
2. A. Kyvelidou, MS, is Graduate Research Assistant, Nebraska Biomechanics Core Facility, University of Nebraska Medical Center and University of Nebraska at Omaha, Omaha, Nebraska.
3. V.S. Mercer, PT, PhD, is Associate Professor, Division of Physical Therapy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.
4. N. Stergiou, PhD, is Isaacson Professor and Director, Nebraska Biomechanics Core Facility, College of Education and College of Public Health, University of Nebraska Medical Center and University of Nebraska at Omaha.