MIR LOCK

The Mir lock is the rotational shoulder lock named after MMA heavyweight Frank Mir, who used the technique to win his UFC Heavyweight Championship via submission of Tim Sylvia at UFC 48 in 2004. The technique resembles a kimura but applies rotational force on the shoulder by twisting the captured arm in a specific axial direction that differs from the conventional kimura's medial rotation. The lock is one of the few modern submissions named after the practitioner who popularized it.

The mechanics begin from side control or mount with the bottom player's arm captured in a kimura-like figure-four grip. Rather than applying conventional kimura rotation (rotating the wrist toward the opponent's head), the attacker applies a rotational twist on the shoulder by levering the captured arm in the opposite direction, with the attacker's body weight providing the torque. The lock targets the rotator cuff and the shoulder capsule with a specific angle that produces injury at lower force than the conventional kimura.

The Mir lock has been used primarily in MMA contexts where the willingness to commit to injurious finishing pressure differs from the BJJ competitive culture. In BJJ the technique is permitted at brown belt and above but rarely seen, in part because the conventional kimura is generally preferred and in part because the Mir lock's specific angle is technically demanding. Defensively the technique is escaped by hand-fighting the figure-four grip aggressively, by rolling toward the attacker to disrupt the angle, or by tap-to-grip when the rotation engages — as with the heel hook, damage can precede pain.