The mixed martial arts or MMA, are a full contact combat sport, based on strikes, grips and ground combat, which incorporates martial arts sports techniques, such as karate, muay thai, Brazilian jiu jitsu, judo, and sports from general combat, such as wrestling, grappling, boxing, kickboxing.
The first documented use of the term mixed martial arts was in a review of UFC 1 by television critic Howard Rosenberg in 1993. They are sometimes improperly called free fight or no holds barred and confused with the vale tudo from which, however, they derive.
The sport reached a new peak of popularity in December 2006 in North America during the UFC 66 fight between then light heavyweight champion Chuck Liddell and former champion Tito Ortiz, rivaling the pay-per-view sales of some of the greatest mixed martial arts bouts ever and helping the 2006 UFC PPV surpass those of any other promotion's PPV in history.
As far as the safety of the athletes is concerned, statistics show that the frequency of KOs in MMA competitions is lower than in boxing competitions and, from studies carried out by the Johns Hopkins University, it has been found that in MMA competitions there is a minor risk of traumatic brain injury compared to other combat sports involving head strikes.