1. SC Dusing, PT, PhD, is Assistant Professor, Department of Physical Therapy, School of Allied Health Professions, Virginia Commonwealth University, 1200 E Broad St, PO Box 980224, Richmond, VA 23298-0224 (USA)
2. DE Thorpe, PT, PhD, PCS, is Associate Professor, Center for Human Movement Science, Division of Physical Therapy, University of North Carolina, Chapel Hill, NC
3. MD Poe, PhD, is Investigator, Frank Porter Graham Child Development Institute, University of North Carolina
4. AE Rosenberg, PT, DrPH, is Assistant Professor, Center for Human Movement Science, Division of Physical Therapy, University of North Carolina, and Training Director, Center for the Study of Development and Learning, University of North Carolina
5. VS Mercer, PT, PhD, is Associate Professor, Center for Human Movement Science, Division of Physical Therapy, University of North Carolina
6. ML Escolar, MD, is Director, Program for Neurodevelopmental Function in Rare Disorders, Center for the Study of Development and Learning, University of North Carolina