1. From the Department of Aging and Geriatrics, Institute on Aging, University of Florida, Gainesville, FL (TMM); the Interdisciplinary Institute for Neuromusculoskeletal Research, Department of Biomedical Sciences, Ohio University, College of Osteopathic Medicine, Athens, OH (BCC); the Laboratory of Epidemiology, Demography and Biometry, National Institute on Aging, Bethesda, MD (MAN and TBH); the