Arm crank

Arm crank is an informal label for the Mir lock — and, more broadly, for several rotational arm submissions that load the elbow or shoulder via twisting rather than straight hyperextension.

Etymology. “Crank” is generic colloquial vocabulary for any rotational submission — neck cranks, arm cranks, shoulder cranks — distinct from straight-axis loading mechanisms (armbars, ankle locks). The label persists because the proprioceptive sensation of being cranked is mechanically distinct from being barred or bent; the term captures that distinction without committing to a specific technique. Precise vocabulary uses the technique name (Mir lock, kimura, americana) rather than the generic “arm crank.”

Mechanics. When the term refers to the Mir lock specifically, the configuration is an overhook above the elbow with the arm folded across the attacker’s torso at roughly a right angle, closed with a gable grip and then turned up and away from the body. The shoulder is loaded in rotation and the elbow in torsion at the same time, which is the rotational vector that separates it from a straight-axis armbar.

Cross-reference. “Mir lock” is the canonical site label for this specific technique; “arm crank” can also refer to other rotational submissions in casual vocabulary. Full mechanical coverage on Mir Lock.