BEIJING, Aug. 18 (Xinhua) -- The following is a brief chronology of injuries suffered by Liu Xiang, the Olympic champion for men's 110m hurdles at the Athens Olympics, who pulled out of the event's heat at the Beijing Olympics on Monday morning.

    -- On Feb. 17, 2006, the National Indoor Athletics Championship organizing committee announced that Liu Xiang would not attend the championship, to be held in Shanghai, because of an ankle injury caused after a training session on Feb. 15.

    -- On May 31, 2008, Liu pulled out of the Reebok Grand Prix in New York allegedly for hamstring injury, the Achilles' heel of a sprinter.

    -- On July 25, 2008, at a ceremony marking the formation of the Chinese Olympic delegation, Liu told Xinhua that he didn't suffer any injury and was training normally.

    -- On Aug. 18, 2008, Liu quit the last heat of the first round at the Beijing Olympics, after a false start. He limped off the track.

    -- At a press conference shortly after the competition, Liu's coach Sun Haiping said that Liu had pulled out for a "heel problem."

    -- Feng Shuyong, head coach of the Chinese Athletics Team, said at the same press conference that Liu's "old injuries," which had been healed to a satisfactory level, had "suddenly worsened" since last Saturday.