Heather Carter, an above-knee amputee, throws a ball to Bob Bahr, a physical therapist, during a therapy session inside the Military Advanced Training Center at Walter Reed National Military Medical Center in Bethesda, Md., April 13, 2016. Carter, a medically retired senior airman, and other amputees receive physical and occupational therapy at the center as they work toward their goals. One of Carter’s goals is to return to competitive softball. (U.S. Air Force photo/Sean Kimmons)