Department of Pediatrics, University of Tennessee Health Science Center, 50 North Dunlap Street, Room 453R, Memphis, TN 38103, USA. Electronic address: wsmith74@uthsc.edu.Department of Physical Therapy, College of Health Professions, University of Tennessee Health Science Center, 930 Madison Avenue, Suite 636, Memphis, TN 38163, USA.Joint Graduate Program in Biomedical Engineering, Department of Orthopedic Surgery and Biomedical Engineering, Campbell Clinic, University of Tennessee Health Science Center, 956 Court Avenue, Memphis, TN 38163, USA.Department of Physical Therapy, Campbell Clinic Orthopaedics, 1400 South Germantown Road, Germantown, TN 38138, USA.Department of Exercise Science, School of Applied Sciences, George Street University House, University, MS 38677, USA.Division of Epidemiology, Biostatistics and Environmental Health, School of Public Health, University of Memphis, 228 Robison Hall, Memphis, TN 38152, USA.