Armlock

An armlock is a single or double joint lock which hyperextends, hyperflexes or hyperrotates the elbow joint and/or shoulder joint. An armlock which hyperflexes or hyperrotates the shoulder joint is referred to as a shoulderlock, and an armlock which hyperextends elbow joint is called an arm bar. Depending on the joint flexibility of a person, armlocks which hyperrotate the elbow joint can also hyperrotate the shoulder, and sometimes vice versa. In this case they are technically referred to simply as armlocks.

Obtaining an armlock requires effective use of full-body leverage in order to initiate and secure a lock on the targeted arm, while preventing the opponent from escaping the lock. Therefore, armlocks are usually more easily performed from a dominant grappling position on the ground such as the mount, side mount, or guard. Armlocks are more difficult to perform when both combatants are standing up, though the stand-up variants are a focus in certain systems such as Chin Na. A failed armlock can sometimes result in the opponent escaping and obtaining a dominant position.

Armlocks are considered less dangerous techniques in combat sports allowing joint locks, and are the most common joint locks used as submission holds. Armlocks not hyperextending the elbow joint are in judo and some other martial arts called ude-garami. Ude-garami is a legal technique in judo competitions, even though depending on how it is applied, it may also affect the shoulder joint, or often primarily the shoulder joint.

In sparring or training, armlocks are generally done in a slow and controlled manner, so that the opponent can submit before any damage is inflicted. In self-defense application, or when applied improperly or with excessive force, armlocks can cause severe ligament damage, dislocation, or bone fractures.

Armbar

An armbar(sometimes called a straight arm bar) is a joint lock which hyperextends the elbow joint. It is typically applied by placing the opponent's extended arm at the elbow over a fulcrum such as an arm, leg or hip, and controlling the opponent's body while leveraging the arm over the fulcrum. It is used in various grappling martial arts, including jiu-jitsu, Brazilian jiu-jitsu, judo, and is one of the most common ways to win a match in mixed martial arts competition[1]. The technique has several variations, with the best known and most effective in competition being the juji-gatame (十字固, cross armlock, technically referred to as ude-hishigi-juji-gatame). The juji-gatame is so common, that "armbar" is often used synonymously with juji-gatame.

Juji-gatame

The juji-gatame can be performed on either one of the opponent's arms. In general, the attacker grabs the wrist of the targeted arm of the opponent, holding and securing it by squeezing it between the thighs of the attacker. The attacker's legs end up across the opponent's chest, with the arm held between the thighs, with the elbow pointing against the thigh or hips. By holding the opponent's wrist to the attacker's chest, the attacker can extend the opponent's arm and hyperextend the opponent's elbow, creating pressure in the elbow joint. The attacker can further increase the pressure by arching his hips against the elbow.