A leglock is a joint lock that is directed at joints of the leg such as the ankle, knee or hip joint. A leglock which are directed at joints in the foot is sometimes referred to as a foot lock and a lock at the hip as a hip lock. Leglocks are featured combat sports and martial arts such as Brazilian jiu-jitsu, Catch wrestling, Mixed martial arts, Sambo, Shootwrestling and Submission wrestling, but are banned in some sports featuring joint locks such as JudoInternational Judo Federation. IJF Referee Rules. www.ijf.org. URL last accessed January 7 2006..
Leglocks are considered more difficult techniques to apply effectively than armlocks, since the legs are generally stronger limbs than the arms. Leglocks requre full body leverage to be effective since they attack large joints, such as the knee. Compared to armlocks, leglocks usually require more intricate positions than the mount, sidemount or guard, and are often considered to be risky because of the possibility of losing position.
In training or sparring, leglocks are applied in a slow and controlled manner, and are often not hyperextended such as in the case of the comparatively dangerous heel hook. Instead, submission is signalled before the lock is fully applied. In self-defense application, or when applied improperly or with excessive force, leglocks can cause muscle, tendon and ligament damage, even dislocation or bone fractures.
An ankle lock (occasionally referred to as a shin lock) is a leglock that it applied to any of the joints in the ankle, typically by hyperextending the talocrural joint through plantar hyperflexion. Ankle locks are often applied in a manner which simultaneously causes a compression lock to the achilles tendon, or sometimes also to the calf muscle.
There are several variations of heel hooks, with the most typical being performed by placing the legs around a leg of an opponent, and holding the opponent's foot in the armpit on the same side. The legs are used to control the movement of the opponents body while the opponent's foot is twisted by holding the heel with the forearm, and using the whole body to generate a twisting motion, hence creating severe medial torque on the ankle. A similar heel hook can be performed by holding the opponen's foot in the opposite armpit, and twisting it laterally; a move which is referred to as an inverted, reverse or inside heel hook.