A form of martial art which combines boxing with elements of karate, in particular kicking with bare feet. Although the true roots of kick boxing date back to Asia 2,000 years ago, modern competitive kick boxing actually started in the 1970s, when American karate experts arranged competitions that allowed full-contact kicks and punches that had been banned in karate. Because of health and safety concerns, padding and protective clothing and safety rules were introduced into the sport over the years, which led to the various forms of competitive kick boxing practiced in the United States today. The forms differ in the techniques used and the amount of physical contact that is allowed between the competitors.