John Faulkner’s research focuses on the mechanical properties of whole skeletal muscles and single skeletal muscle fibers from young and old mice. He and his colleagues study the changes that occur in the mechanical properties of skeletal muscle fibers from muscles of wild type, knockout, and transgenic mice during and following injury, fatigue and regeneration. Skeletal muscle fibers are injured by diseases; reactive oxygen species, direct injury; extremes of temperature; ischemia; and high forces developed during contractions. The goal is to devise techniques to reduce the deficits. He is particularly interested and involved in studies of the aging of skeletal muscle and skeletal muscle fibers of humans.