Be careful the next time you cheer your country on at a sporting event. One Chinese fan discovered that the hard way after shouting 'Go! Go! Go!' during the BMX competition won by Hong Kong's Steven Wong.
After cheering lustily, the fan found to his horror he was unable to close and open his lower jaw. He had dislocated his mandible.
Perhaps, he hadn't read the guide book on etiquette handed out by Games organisers many moons ago.
Now doctors are advising fans not to shout too loudly because their chops are in danger of being dislodged, as if that is going to help the poor guy now.
Wu Jinhui, a doctor at the Guangdong Armed Police Hospital, said this was a common occurrence at sporting events.
Wu said people should prop up the lower jaw when yawning and should avoid opening their mouths too wide.