Steve LaRocque’s left knee began protesting around mile 18, first with a twinge of stiffness and then a general unwillingness to bend. It wasn’t long before a dull ache soon enveloped his scarred tendons. The pain showed how far he’s come. Thirteen months ago, the Fort Carson soldier was in a helicopter over Afghanistan being flown to a hospital after a bullet from insurgents tore through that knee. On Sunday, he was legging through the pain in the Rock ‘n’ Roll Denver Marathon. “I’ve always wanted to run one and I’ve just kind of put it off,” said LaRocque, 34, a first sergeant in the 3rd squadron, 61st cavalry of the 4th Brigade Combat Team, 4th Infantry Division. “The realization that I might not be able to run kind of pushed me to do this.” The revelation came on Sept. 10, 2009 in Afghanistan’s Kunar province, where, while patrolling with Afghan troops, insurgents attacked his platoon with what seemed like a machine gun.