Joint Locks: Arms, Legs, and Safe Practice

Joint locks fall into a few mechanical families: straight arm locks that extend the elbow, bent arm locks that rotate the shoulder, and leg locks that load the knee or ankle. Each needs the same two ingredients, isolation of the limb and a fixed point to lever against. Because the margin between control and injury is narrow, particularly at the knee and shoulder, these are trained slowly, with partners who tap early and a coach supervising.

Key points

• Isolate the limb before applying anything, since a lock on an arm your partner can still retract is only a warning.
• Every lock needs a fulcrum and a lever, so check what your hips or forearm are genuinely bracing against.
• Straight arm locks load the elbow with the thumb turned upward, and rotating the wrist changes which joint receives the force.
• Leg locks reach their limit with far less warning than arm locks, so apply them more slowly and stop sooner in practice.
• Never twist, wrench or add speed to a lock, because the extra force adds nothing except a higher chance of injury.

Common mistakes

• Cranking a submission to force a tap, which turns a training repetition into an injury and dismantles your partner's trust.
• Applying knee-loading or twisting leg attacks without instruction and supervision, where damage often arrives before any pain registers.
• Holding on an extra moment after the tap to prove the lock was tight, a habit that ends partnerships and shortens careers.

Put it into practice