In the wake of Liu Xiang's withdraw from the race, how much is he affected by the public pressure? Or it's a pure physical injury?

Oh I’d think that if there was pressure to do anything, it would have been to stay in the race. He’s born and bred to be an Olympic athlete, and he was pretty much their only hope for a medal in track . I’d say it was a real injury, and he’s going to take some pretty harsh heat for withdrawing. That’s my take.

It would have been the pinnacle of his career to repeat his win at home. Great athletes want to compete more than anything. From chinaview:

He is definitely injured. “But the Shanghai native winced in pain after leaping over only a few hurdles in warm-up. A right foot injury was obviously hindering his movement as he staggered back to the starting point.”

He was definitely under tremendous pressure to compete: “In his telegram, Xi expressed his hope that Liu, after he recovered, would make harder efforts for the national glory.”