CAMP GRAYLING, Mich. – U.S. Marine Sgt. Kevin Eskins, a combat engineer with 4th Combat Engineers Battalion, 4th Marine Division, Marine Forces Reserve, demonstrates a horizontal hammer fist during a Marine Corps Martial Art Program course at Camp Grayling, Michigan, during exercise Northern Strike 2017, July 31, 2017. Northern Strike 2017 brought together Reserve Marine from across the country to provide realistic combined arms trainings to cover a spectrum of combat scenarios. (U.S. Marine Corps photo by Lance Cpl. Niles Lee/Released)