Inside Heel Hook

Last updated: June 18, 2026

What is an inside heel hook?

An inside heel hook belongs to the family of leg locks, submissions that go after the lower body rather than the neck or arms. The grip lands on the heel, but the real target sits higher up, at the knee. By trapping the foot and turning the heel toward the opponent’s other leg, the attacker forces the lower leg to rotate against the joint, and the knee has little room to absorb that twist.

Grapplers also call this version the inverted heel hook or the reverse heel hook. All three names point to the same thing: a heel hook applied with inward, or medial, rotation. The outside heel hook works in the opposite direction.

The submission earns its reputation because it can end a match in seconds and hurt a knee before the person caught in it feels much pain at all. That mix of speed and quiet damage is why coaches treat it with caution and why most rule sets restrict who is allowed to use it.

How the inside heel hook works

Recognising an inside heel hook starts with the position around it. Before any rotation happens, the attacker has to trap the leg in a controlling entanglement so the knee cannot simply spin away from the pressure. Grapplers know these positions by names such as ashi garami, the inside sankaku (often called the saddle or the 411), and the 50/50.

From inside that control, the attacker catches the heel and turns the foot inward while bridging the hips into the side of the knee. The twist travels from the heel through the ankle and into the knee. Because the inward angle stops the ankle from soaking up much of the force, most of that torque arrives at the knee joint, which is what makes the position so threatening.

Inside heel hook vs outside heel hook

Most people searching for the inside heel hook are trying to tell it apart from its sibling, the outside heel hook. The two can look similar from across the mat, yet they rotate in opposite directions and put the danger in different places.

Feature	Inside heel hook	Outside heel hook
Rotation direction	Heel turns inward (medial)	Heel turns outward (lateral)
Attacker’s position	Body aligned inside the opponent’s leg	Body sits outside the leg line
Where the force lands	Mostly the knee, with little ankle relief	Shared between the knee and the ankle
Relative danger	Higher; treated as the more damaging version	Lower; the ankle absorbs part of the twist
Common entanglements	Inside sankaku (saddle), 50/50	Standard ashi garami, outside ashi

The direction matters more than it sounds. On the outside version, some of the rotation escapes into the ankle and spares the knee a little. The inside heel hook does the opposite. Its inward angle drives the twist straight into the joint, which is why most high-level finishes in modern no-gi grappling are inside heel hooks.

Why the inside heel hook is considered so dangerous

Three things stack together to make this submission so risky.

First, the knee has little natural defense against rotation. Mike Piekarski, a doctor of physical therapy and former MMA fighter, explains that the anterior cruciate ligament (ACL) is the main structure resisting internal rotation of the shin, and the mechanics of the inside heel hook let the attacker isolate that rotation at the knee rather than letting it leak into the ankle. The outside version, by comparison, often loads the ankle first.

Second, ligaments carry few pain receptors. A knee can be moments from a tear while the person feels only mild discomfort, so the usual warning that tells a grappler to tap arrives late, or never.

Third, the injuries are serious. Natural Movement Physio, a clinic that has broken down the mechanics of the technique, notes that the inside variation drives most of its force into the knee, where damage to the cruciate ligaments and meniscus often needs surgery and months away from training.

The inside heel hook in MMA

Heel hooks are legal in the UFC and the other major MMA promotions, which sets the sport apart from traditional jiu-jitsu competition. The IBJJF only began allowing them in no-gi for brown and black belts in 2021, and still bans them in the gi, while submission-grappling events such as ADCC have permitted them at every level for years.

Inside the cage, the heel hook is the leg lock a fan is most likely to see, and the inside version is the finish grapplers chase once they trap the knee line. Fighters often enter through a rolling attack such as the Imanari roll, named after Masakazu Imanari. Many still use the position carefully, since diving for a leg from the bottom can hand an opponent top position if the attempt fails.

Frequently Asked Questions

Is the inside heel hook more dangerous than the outside heel hook?

Generally, yes. Both attack the knee, but the inside version channels more of the rotation into the joint while the outside version lets the ankle take some of the load, so most coaches treat the inside heel hook as the more damaging of the two.

What is the difference between an inside heel hook and a reverse heel hook?

There is none. Inside heel hook, inverted heel hook, and reverse heel hook are three names for the same submission, applied with inward rotation of the heel.

What does an inside heel hook injure?

The knee, above all. Sources describe the exact structures differently, but the inward twist commonly threatens the cruciate ligaments (such as the ACL), the medial collateral ligament, and the meniscus, since these tissues resist the rotation the submission forces.

Is the inside heel hook legal in MMA?

Yes. It is legal in the UFC and other major MMA organisations, though fighters reach for it less often than chokes or armbars.

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Sources

1. BJJ Heroes, “Heel Hook,” accessed June 2026.
   https://www.bjjheroes.com/techniques/heel-hook
2. Evolve Daily, “Inside vs Outside Heel Hook: Differences, Effectiveness, and When to Use Each,” accessed June 2026.
   https://evolve-mma.com/blog/inside-vs-outside-heel-hook-differences-effectiveness-and-when-to-use-each/
3. BJJ Eastern Europe, with physical-therapy analysis from Mike Piekarski, “What’s More Dangerous: Reverse or Outside Heelhook?”, accessed June 2026.
   https://www.bjjee.com/articles/whats-more-dangerous-reverse-or-outside-heelhook/
4. BJJ More, “Heel Hook: The Complete Guide to BJJ’s Most Dangerous Submission,” accessed June 2026.
   https://bjjmore.com/heel-hook/
5. Natural Movement Physio, “Knee Injuries from a Heel Hook,” accessed June 2026.
   https://www.naturalmovementphysio.com/blog/kneeinjuriesheelhook
6. Digitsu, “Heel Hook Breakdown,” accessed June 2026.
   https://digitsu.com/t/heel-hook
7. BJJ World, “What Happens to Your Knees from a Heel Hook Injury?”, accessed June 2026.
   https://bjj-world.com/heel-hook-injury-knee-damage/

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