Leah Melquist (left), Health and Wellness Center health promotion manager, and Senior Airman Morgan Mesa, 69th Reconnaissance aircraft structural maintenance apprentice, perform kickbacks at the running clinic Sept. 2, 2014, on Grand Forks Air Force Base, North Dakota. Kickbacks are used to strengthen core muscles and gluteal muscles. Keeping core and leg muscles strong minimizes the risk of injury. (U.S. Air Force photo/Airman 1st Class Bonnie Grantham)