Competitors leave the starting blocks during a 100-meter sprint heat during the Invictus Games 2014 in London Sept. 11, 2014.
The Invictus Games are the United Kingdom's version of the Warrior Games, bringing together wounded veterans from 14 nations for events including track and field, archery, wheelchair basketball, road cycling, indoor rowing, wheelchair rugby, swimming, sitting volleyball and a driving challenge. (DoD photo by Mass Communication Specialist 2nd Class Joshua D. Sheppard, U.S. Navy/Released). Original public domain image from Flickr