1. Department of Aerospace and Mechanical Engineering, University of Notre Dame, Notre Dame, Indiana.
2. Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania, Philadelphia, Pennsylvania.
3. Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.
4. Department of Orthopaedic Surgery, Indiana University School of Medicine, Indianapolis, Indiana.
5. Richard L. Roudebush VA Medical Center, Indianapolis, Indiana.