1. Department of Geriatrics, Reynolds Center on Aging (S.O.R., B.L.-C.), University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205
2. Department of Orthopaedic Surgery, Center for Orthopaedic Research (L.J.S., D.G., D.C.M.), University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205
3. Department of Physiology and Biophysics (L.J.S., D.G, D.C.M.), University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205