As a tribute to Masahiko Kimura's victory over Helio Gracie in 1955, the reverse ude-garami technique has since been commonly referred to as the Kimura lock, or simply the "Kimura", in
Brazilian Jiu-Jitsu and, more recently, mixed martial arts circles.
A keylock (also known as a Kimura,
bent armlock, figure-four armlock or ude-garami) involves holding the forearm and using it to
twist the upper arm laterally or medially, similarly to turning a key in a keyhole. It is usually considered to be a shoulder lock since the primary pressure is often on the shoulder, but depending on how it is performed, significant pressure can also be applied to the
elbow. It passes for a lock on the
elbow in judo competitions, where only
elbow locks are allowed. It can be applied from a multitude of positions, and it is the most
common shoulder lock used as a submission hold in mixed martial arts competition. The keylock has several variations with their own names, for instance depending on in which direction the arm is rotated. The word "reverse" is sometimes added to signify medial rotation as in reverse keylock or reverse ude-garami, in which
case the usage of just "keylock" indicates lateral rotation.
References:
en.wikipedia.org/wiki/Masahiko_Kimura
en.wikipedia.org/wiki/Armlock#Kimura_.28Gyaku_ude-garami.
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www.grapplearts.com/Kimura-Article.htm
en.wikipedia.org/wiki/Kimura
"Wherever you
see grapplers competing, whether in Pride, the
UFC, Abu Dhabi or the Jiu-jitsu Mundial, you
see the Kimura lock used to submit opponents and win matches!"