A U.S. Marine Corps candidate assigned to Lima Company, Officer Candidates School, back crawls through an obstacle while navigating through the combat course at Marine Corps Base Quantico, Va., June 4, 2014.
The Combat Course consisted of a series of obstacles to include the "Quigley," through which a four-person fire team had to maneuver. (DoD photo by Staff Sgt. Ezekiel R. Kitandwe, U.S. Marine Corps/Released). Original public domain image from Flickr