President Gerald Ford had a particularly amusing knee injury; apparently, it made him fall down. Or at least, that's what he claimed. While visiting Austria in 1975, the President's bum knee gave way and he tumbled down the Air Force One stairs. A few more falls (one was even up the stairs) combined with Chevy Chase's Saturday Night Live pratfall routine, earned the former University of Michigan football star a reputation as a bumbling klutz. Well, at least it's better than no reputation at all.