U.S. Air Force 1st Lt. Spencer Carrier, 86th Operational Medical Readiness Squadron physical therapist, watches Staff Sgt. Randy Sayer, 86th OMRS physical therapy technician, balance on a BOSU ball at Ramstein Air Base, Germany, Jan. 13, 2021. This technique is used for strength and flexibility training during physical therapy. (U.S. Air Force photo by Senior Airman Jennifer Gonzales)