U.S. Air Force Senior Airman Michael Hall, 20th Aerospace Medicine Squadron flight and operation medical technician, center, runs alongside two other participants in a 5K at Shaw Air Force Base, S.C., Feb. 25, 2017. The Muscular Dystrophy Association chose Hall to represent them in the 2017 Boston Marathon on “Team Momentum,” a group that encourages its members to dedicate their miles to individuals with muscular dystrophy, amyotrophic lateral sclerosis (also known as Lou Gehrig’s disease) and other life-threatening diseases. Hall runs for his sister, Danielle, who has lived with muscular dystrophy for 27 years, and his brother DJ, who passed away from the disease when he was 19 months old. (U.S. Air Force photo by Airman 1st Class Kelsey Tucker)