1. Amputation Prevention Center, Broadlawns Medical Center, Des Moines, IA.
2. Cardiovascular Research Group, Division of Cardiovascular and Endocrine Sciences, Department of Medicine, Manchester Royal Infirmary and Manchester University, Manchester, England.
3. Center for Lower Extremity Ambulatory Research (CLEAR), Dr. William M. Scholl College of Podiatric Medicine, North Chicago, IL.