Wristlock

Wristlocks are very common in martial arts such as chin-na, aikido, hapkido and jujutsu where they are featured as self-defense techniques.

They are also used as submission holds in martial arts such as Brazilian jiu-jitsu (where the most common name is mão de vaca, "the cow's hand") and catch wrestling.

The wristlock is a technique that can be applied from a stand-up position, simply by grabbing the opponent's hand and twisting and/or bending it in a non-natural direction.

It is considered to be a relatively safe technique to practice with a willing opponent,[4] but if applied suddenly and/or forcefully, a wristlock can cause ligament tears or possibly even dislocation or bone fractures.

Once the radius and ulna have been brought to their extreme positions, further twisting motion will put severe torque on the wrist.

In martial arts, standing rotational wristlocks are often accompanied by the opponent instinctively throwing him or herself to escape or alleviate the lock.

The goal of almost all throws executed via joint/bone manipulation, at least from the perspective of some classical (koryu) martial arts, is to break or dislocate a limb(s).

An adductive wristlock (in budō referred to as kote hono gaeshi, "partial forearm return", part of aikido's nikyō, or second teaching, in its ura form) involves forced ulnar deviation of the hand.

Rotational wristlock by an Aikido instructor
A supinating wristlock demonstrated.
Pronating wristlock in a professional wrestling match. Here, William Regal is applying the hold to Cody Rhodes .
A hyperflexing wristlock used as a pain compliance technique .
By pressing the opponent's wrist downwards, the hand is forced into extreme ulnar deviation .