suffered a serious injury performing in "spider-man" on broad way is expected to leave rehab this week. his father says his son is in better health. here's amateur video shot of that injury. he's up now walking and doing very well according to his father, and his father says christopher cannot wait to go back to the show. well, accidents like this are raising concerns as you can imagine about the overall safety of stunt performers. cnn's susan candiotti takes a look at the dangers involved. >> reporter: they're fleeing moves are stunningly beautiful and a bit frightening to watch. >> when you're performing a trick and it's something a little bit sudden or quick or swift, it can happen. it's really exciting. >> reporter: there are risks. when the knots hold? will the rigging bear the acrobatic's weight? >> if you forget a line or step, if you fall game over.