1. Department of Physical Therapy and Rehabilitation Science University of California San Francisco California USA
2. Department of Radiology and Biomedical Imaging University of California San Francisco California USA
3. Department of Orthopaedics University of Colorado Aurora Colorado USA
4. Physical Therapy Program, Department of Physical Medicine and Rehabilitation University of Colorado Aurora Colorado USA
5. VA Eastern Colorado Geriatric Research, Education, and Clinical Center (GRECC) VA Eastern Colorado Healthcare System Aurora Colorado USA
6. Department of Medicine University of Vermont Burlington Vermont USA
7. Department of Orthopaedics and Rehabilitation University of Vermont Burlington Vermont USA
8. Department of Molecular Physiology and Biophysics University of Vermont Burlington Vermont USA