1. Department of Physical Medicine and Rehabilitation, Physical Therapy Program, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
2. Department of Geriatrics, Geriatric Research, Education, and Clinical Center, VA Eastern Colorado Healthcare System, Aurora, CO, USA
3. Department of Mechanical Engineering, University of Colorado Denver, Denver, CO, USA
4. Center for Bioengineering, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
5. University of Colorado, Hospital, Aurora, CO, USA
6. Department of Orthopedics, University of Colorado Anschutz Medical Campus, Aurora, CO, USA