1. RR&D Center of Excellence for Limb Loss Prevention and Prosthetic Engineering, VA Puget Sound Health Care System, Seattle, WA, USA
2. Department of Mechanical Engineering, University of Washington, Seattle, WA, USA
3. Department of Orthopaedics & Sports Medicine, University of Washington, Seattle, WA, USA
4. Department of Radiology, University of Washington, Seattle, WA, USA