Before the 1970's karate movies were only really popular in Asia, where they had been made for years, but that all changed when the world met Bruce Lee. Enter The Dragon, which was released in 1973, made a superstar out of Lee posthumously, but the true star - http://www.caringbridge.org/search?q=true%20star that was introduced was martial arts. The genre took the world by storm, and introduced to the world a new form of actor. These actors did not have thespian training as much as martial arts, and so instead of delivering a line, they would do a fly kick through the air.