Master Sgt. Nathan Carlson, 219th Security Forces Squadron health technician, touches his toes to locate pain in his back on Minot Air Force Base, N.D., May 22, 2014. Locating and testing pain levels are the first steps in battlefield acupuncture before inserting the studs into the ear. (U.S. Air Force photo/Airman 1st Class Sahara L. Fales)