The Kimura is one of the most famous techniques in the history of Mixed Martial Arts in that it is a technique named after Masahiko Kimura, the famous Japanese judoka who used the reverse ude-garami arm lock to defeat Hélio Gracie, one of the founders of Brazilian Ju Jitsu and father of UFC 1 winner Royce and UFC co founder Rorion. In effect, the bout was one of the most high profile fights between different styles of its era and is a spiritual precursor to the MMA we know today.
The Kimura is a simple, yet effective lock that involved interlocking your arms against your opponents arm and using the leverage and pressure from the joint of their elbow to achieve a submission. It can be achieve from a variety of positions, but is often most effective at turning a defensive guard position into a dominant submission. In the below video we are shown how to achieve the hold from multiple angles. Bonus points for spotting the young guy getting his arm twisted as current undefeated UFC standout Brian Ortega!