Kimura (Brazilian Jiu-Jitsu), chicken wing/double wrist lock (catch wrestling), or reverse keylock are terms used to specify a medial keylock known in judo as gyaku ude-garami (reverse arm entanglement) or simply as ude-garami. The application is similar to the americana, except that it is reversed. It needs some space behind the opponent to be effective, and can be applied from the side control or guard. Contrary to the americana, the opponent’s wrist is grabbed with the hand on the same side, and the opposite arm is put behind the opponent’s arm, again grabbing the attacker’s wrist and forming a figure-four.
By controlling the opponent’s body and cranking the arm away from the attacker, pressure is put on the shoulder joint, and depending on the angle, also the elbow joint (in some variations the opponent’s arm is brought behind their back, resulting in a finishing position resembling that of the hammerlock outlined below). The kimura was named after the judoka Masahiko Kimura, who used it to defeat one of the founders of Brazilian jiu-jitsu, Hélio Gracie. Because Americana is a reverse Kimura, in UFC fights, Bruce Buffer still announces fights won by Americana as “by tap-out due to a kimura.
In this video, Jason Scully demonstrates 49 different Americana and Kimura style attacks from many different situations in less than 6 minutes: