Wiktionary
n. (context combat sports English) Any lock designed to hyperextend one of the joints of the body, leading to pain and/or injury.
Wikipedia
A joint lock is a grappling technique involving manipulation of an opponent's joints in such a way that the joints reach their maximal degree of motion.
In judō these are referred to as, 関節技 kansetsu-waza, "joint locking technique") and in Chinese martial arts as chin na which literally means "catching and locking".
These typically involve isolating a particular joint and leveraging it in an attempt to force the joint to move past its normal range of motion. Joint locks usually involve varying degrees of pain in the joints and, if applied forcefully and/or suddenly, may cause injury, such as muscle, tendon and ligament damage and even dislocation or bone fracture.
In judo, the combining of standing locks with throws is forbidden due to the risk of physical harm to the falling opponent, while jujutsu, taijutsu, aikido and hapkido allow their use.
Joint locks can be divided into five general types according to which section of the body they affect:
- Armlocks
- Leglocks
- Small joint manipulation
- Spinal locks
- Wristlocks
These general types can be further divided into subtypes according to which specific joint(s) they affect, or the type of motion they involve.
Usage examples of "joint lock".
Using the joint lock as a lever, I turned her over on her stomach, increasing the pressure to almost breaking, but not quite.
I used my leg and one arm to keep the joint lock on but knelt over her upper body, until my weight would keep her pinned.
A joint lock on an elbow hurts enough that most people will negotiate after you prove just how much it hurts.
Well, Jason was struggling in a joint lock that Shang-Da had on his arm, but no one else had tried to help.