1. Private practice, Flagstaff, AZ.
2. Southern Arizona Veterans Affairs Medical Center, Tucson.
3. Department of Medicine, Manchester Royal Infirmary, University of Manchester, Manchester, England.
4. School of Public Health, University of Arizona, Tucson.
5. Scholl’s Center for Lower Extremity Ambulatory Research, Rosalind Franklin University of Medicine and Science, North Chicago, IL.