1. Muscle Morphology, Mechanics, and Performance Laboratory, Human Performance Research Unit, Clinical Research Center Washington DC USA
2. Research Service Washington DC USA
3. Geriatrics ServiceVeterans Affairs Medical Center Washington DC USA
4. Department of Exercise and Nutritional SciencesMilken Institute School of Public Health
5. Department of Bioengineering, Volgenau School of EngineeringGeorge Mason University Fairfax Virginia USA
6. Departments of Medicine Washington DC USA
7. Biochemistry and Molecular Medicine, School of Medicine and Health SciencesGeorge Washington University Washington DC USA
8. Departments of Medicine and Rehabilitation MedicineGeorgetown University School of Medicine Washington DC USA