Johnny Knoxville who regularly completes dangerous stunts on the MTV show was rushed to hospital after his attempt to back flip on a motorcycle went wrong. He wrote on his official blog: “I’ve just got back from Oklahoma where I was shooting ‘Mat Hoffman’s tribute to Evel Knievel.’ I had a ball, too, even though I almost lost my own balls in the process! “I don’t want to give too much away because it doesn’t air until February 23, but let’s just say before I did a back-flip on a motorcycle I should have learned how to ride one first,” he continues “I have to go now. I have to…