HEEL HOOK (INSIDE SANKAKU)

The inside heel hook is the most controversial and the most efficient submission in the modern grappling game. By rotating the opponent's foot away from the centerline while the knee is locked between the attacker's legs in inside sankaku position, the attack tears ligaments in the knee — the ACL, MCL, and LCL — in less than half a second once the rotation begins. Unlike most submissions which give pain before damage, the heel hook gives damage before pain, which is why it is considered the most dangerous submission in mainstream competition.

The defining position for the inside heel hook is the inside sankaku — a figure-four with the attacker's legs trapping the opponent's leg between them, the inside leg bent and pinning the knee while the outside leg pressures the hip. From this position the attacker grips the heel with both hands in a Kimura-style grip, with the thumb tucked away to avoid being caught. The finish is a rotation of the heel inward and upward, transmitting torque through the ankle into the knee. Because the knee is locked, all of the rotation is absorbed by the knee ligaments — there is no joint slack available, which is why elite competitors are taught to tap to grip, not to pressure.

The leg-lock revolution of the mid-2010s transformed the heel hook from a banned technique avoided even in nogi competition into the centerpiece of the modern submission grappling game. John Danaher's New Wave team, beginning with Eddie Cummings and continuing through Garry Tonon, Gordon Ryan, and Craig Jones, demonstrated that the inside heel hook from a properly entered position was effectively impossible to defend against, and the technique now decides more ADCC matches than any other submission. It is illegal in IBJJF gi competition for safety reasons, but legal in IBJJF nogi at brown belt and above, and legal in essentially every modern no-gi promotion.