1. Harvard-MIT Division of Health Sciences and Technology77 Massachusetts Avenue, Cambridge, MA 02139, USA
2. Department of Biomedical Engineering, Tufts University4 Colby Street, Medford, MA 02155, USA
3. Orthopedic Biomechanics Laboratory, Beth Israel Deaconess Medical Center, Harvard Medical School330 Brookline Avenue, Boston, MA 02215, USA