Overhook shoulder lock

Overhook shoulder lock is the descriptive name for the Mir lock — the shoulder submission that folds a bent arm across the attacker’s torso from an overhook and turns it up and away.

Etymology. The technique’s own name is eponymous and says nothing about its mechanism, which matters more here than usual: the Mir lock is thinly documented and sources place it in different positions, so the control is the only stable identifier. Naming the overhook names the thing every source agrees on.

Mechanics. The overhook is taken above the elbow, as near the armpit as the position allows — taken lower, the shoulder can still rotate underneath it. The opponent’s arm is folded across the attacker’s chest with the elbow at roughly a right angle and crushed in until there is no gap, making the chest the fulcrum. A gable grip or hand-on-own-hand clasp then closes arm, chest and grip into one unit, and the finish turns that unit up and away while the torso moves backward to lengthen the lever. The shoulder loads in rotation and the elbow in torsion together.

The bent arm is the requirement. A straight arm has nothing to fold and no short lever to turn, which makes this the rare arm attack that the standard keep-the-elbow-tucked reflex walks into rather than away from. Defence is denying the overhook, not shortening the arm.

Cross-reference. “Mir lock” is the canonical site label; “arm crank” is the looser colloquial term. Full mechanical coverage on Mir Lock.