1. From the Department of Rehabilitation Medicine (S.L.W., S.R.B.), Departments of Medicine and Cell Biology (S.L.W.), Emory University School of Medicine, Atlanta, Ga; Methodology and Data Analysis Center (P.A.T.), Sanford Research/University of South Dakota, Vermillion, SD; Division of Biostatistics (J.P.M.), Washington University School of Medicine, St. Louis, Mo; Division of Biokinesiology and Physical Therapy at the School of Dentistry (C.J.W.), University of Southern California, Los Angeles,...