What is a kimura?

A kimura is a shoulder lock (double wristlock / gyaku ude-garami) where you control their wrist, thread your other arm under their upper arm, figure-four your own wrist, and rotate their shoulder past a safe range until they tap. It is named after judoka Masahiko Kimura, famous for finishing Helio Gracie with the lock. Basic mechanics: isolate one arm, connect a figure-four grip (your hand on their wrist, other hand grabbing your own wrist), keep their elbow tight to your body, then rotate their hand toward their hip or head depending on the entry while keeping the elbow pinned. Common entries: side control, north-south, closed guard, half guard, and turtle. From top, pin the arm and walk toward the head. From guard, break posture, isolate the arm, and hip out to create the angle. Kimura vs americana: both attack the shoulder, but the rotation direction differs. Kimura usually rotates the hand behind the back; americana paints the hand toward the hip while the elbow stays on the mat. Defense starts early: straighten the arm, grab your own belt/gi, or shrimp to relieve the angle before the figure-four locks tight. Train carefully. Shoulder tissue fails before ego does. Tap early and drill the grip and angle before cranking.