FILE - The Aug. 18, 2008 file photo shows China's Liu Xiang leaving the track after being injured in a men's 110-meter hurdles first round heat during the athletics competitions in the National Stadium at the Beijing 2008 Olympics in Beijing. Former champion Liu Xiang left the London Olympics Games Tuesday, Aug. 7, 2012 in the first heat of the 110-meter hurdles for the second time in a row, clutching his right Achilles after he crashed into the first obstacle. Liu won in 2004 at Athens to become the first Chinese man to claim an Olympic track and field gold medal, but shocked the home crowd in Beijing four years later when he had to withdraw in his heat without clearing a hurdle because of a right foot problem which later required surgery. (AP Photo/Kevin Frayer)