1. School of Health Professions Research Collaborative and National Center on Health, Physical Activity and Disability (NCHPAD), University of Alabama at Birmingham, Birmingham, AL 35233, USA
2. Department of Physical Therapy, School of Health Professions, University of Alabama at Birmingham, Birmingham, AL 35233, USA
3. Department of Pediatrics, School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35233, USA