E.R. star John Stamos came to the aid of an extra on the show after he fell and dislocated his knee. The actor - who plays paramedic Tony Gates in the hit show - leaped into action and packed ice around the fallen actor's joint before popping it back into place.

He said, "You dislocated it. I did the same thing to my own knee. Keep the ice on it for a while. It should be fine."

Stamos stayed with the extra until a studio nurse - who confirmed his diagnosis - could attend to him.