China's Liu Xiang (C) is helped off the track by Britain's Andrew Turner (L) and Spain's Jackson Quinonez after crashing into the first hurdle and failing to finish his men's 110m hurdles round 1 heat at the London 2012 Olympic Games at the Olympic Stadium August 7, 2012. Liu crashed out of the heats in the 110 metres hurdles in an echo of his injury-induced withdrawal from the same stage of the Beijing Games four years ago. REUTERS/David Gray (BRITAIN - Tags: OLYMPICS SPORT ATHLETICS)