The heel hook: how it works and how to do it safely
Our AI analyses your rolls. Free to try.
Try a free analysis
By Scott Flear, founder of JitsAI.
A heel hook is a leg lock that twists the knee: you trap your opponent’s leg so the thigh can’t move, then turn their heel, which turns the shin against the thigh. The outside heel hook turns the shin inwards, with the ACL first in line; the inside heel hook turns it outwards and loads the back outer corner of the knee (Hasegawa et al. 2026). The knee gives little warning before damage, so tap as soon as your leg is trapped and you feel the twist.
What is a heel hook?
The heel hook is the leg lock with the scary reputation. You control your opponent’s leg in a leg entanglement (ashi garami), use their heel as a handle and rotate. In IBJJF competition it’s legal only for adult brown and black belts in no-gi. It’s banned in the gi at every belt, and in every other no-gi division (IBJJF Rule Book v6, 2024).
There are two main versions. In the outside heel hook the pinky-toe side of their foot is on your chest; in the inside heel hook, the big-toe side. They twist the knee in opposite directions, so they load different structures.
How does a heel hook work?
The heel is the handle. Pin the thigh, turn the heel, and the shin twists against the thigh, so the twist lands in the knee.
- Pin the thigh first. Trapping the hips and the knee holds the thigh still. Any slack, the knee sliding or the hip turning, bleeds the twist away (Hasegawa et al. 2026).
- Outside heel hook: the shin turns in. Turning the shin inwards loads the ACL when the knee is fairly straight, then the ligaments on the inner side of the knee (Hasegawa et al. 2026; Markolf et al. 1995).
- Inside heel hook: the shin turns out. Turning the shin outwards loads the posterolateral corner, the group of ligaments and tendons at the back outer corner of the knee (Hasegawa et al. 2026). That direction barely loads the ACL (Markolf et al. 1995), so “every heel hook tears the ACL” isn’t right.
Either way, the knee gives little warning before damage. That’s why heel hooks have the reputation they do.
Two episodes from our Anatomy Series. Episode 10 compares how much twist your shin muscles can resist with how much twist tore the ACL in donor knees in a lab, and says plainly that a lab test isn’t a real heel hook. Episode 12 is a thought experiment: a heel hook on a gorilla.
How do you do a heel hook?
These steps are the outside heel hook from outside ashi garami, as leg-lock coaches like Eddie Cummings teach it. Drill it only when your coach says you’re ready, and only ever finish it slowly.
- Step 1: Enter outside ashi. Your inside leg goes between their legs and your outside leg crosses over their hip. Their knee should be inside the line of your hips.
- Step 2: Control the knee line. Pinch your knees and keep their knee trapped inside the line of your hips, with your knee pointing the same way as theirs.
- Step 3: Expose the heel. Put a C-grip on their calf with your overhooking arm, without reaching across, and turn the heel out so their knee can’t come back past the line.
- Step 4: Lock the heel. Put the pinky-toe side of their foot on your chest, not the top of the foot, and pinch your elbow down. Lock your hands and keep them tight to your chin.
- Step 5: Turn slowly, as one piece. Keep backheeling so the knee can’t create slack, then turn your upper body slowly as one unit. Let go the moment they tap.
Common heel hook mistakes
- Going for the heel before the leg is controlled. If their hips and knee can still move, they turn out of it, or you end up twisting a leg that’s spinning. Control the leg first, then expose the heel.
- A loose knee line. If their knee slides past your hips, the twist goes nowhere. Keep the knee pinned.
- Holding the top of the foot. The heel is the handle. With the top of the foot on your chest, the heel slips. Trap the heel with the pinky-toe side against your chest.
- Turning fast. In training, a fast heel hook leaves no time to tap. Turn slowly, and let go on the tap.
Leg locks follow the same rule as arm locks like the armbar and the kimura: pin one part of the limb, move the other. If you’re the one caught, the earlier you move the better, the same as the escapes on our side control and mount escapes page.
What happens if you don’t tap to a heel hook?
Your knee twists until the structures holding it together give. In the outside heel hook, the ACL is first in line when the knee is fairly straight, then the ligaments on the inner side. In the inside heel hook, it’s the posterolateral corner (Hasegawa et al. 2026). Complete tears of that corner rarely heal without surgery (Chahla et al. 2016).
Heel hooks do hurt people, though in the survey data they’re behind the arm locks. In a survey of 1,140 grapplers, heel hooks were the third most common submission to injure the person caught: 27 cases, 11% of those injuries, behind the armbar and the kimura (Hinz et al. 2021).
The most direct evidence is newer, and rough. Among IBJJF brown and black belts in 2021, competitors exposed to heel hooks had 26.5 knee injuries per 1,000 matches against 2.2 for those who weren’t, while ankle injuries showed no significant difference (Piekarski et al. 2026). The relative risk was 12, but with a 95% confidence interval of 1.5 to 96.1, the study is cross-sectional, and only the abstract is public so far. Read it as a warning, not a precise multiplier.
How to train heel hooks safely
- Tap early. Tap when your leg is trapped and you feel the twist, not when it hurts. The knee gives little warning before damage.
- Finish slowly and let go on the tap. Turn slowly in training and release the moment your partner taps.
- Train under a qualified coach. Learn leg locks from a coach who teaches them, with partners you trust, and only when your coach says you’re ready.
- Know the rules. In IBJJF events, heel hooks are legal only for adult brown and black belts in no-gi. Other events have their own rules, so check before you compete.
- Get checked if something’s wrong. Seek medical care for knee pain, swelling or a knee that feels unstable after a leg lock.
Does your heel hook land on everyone, or only on beginners?
Finishing a white belt and finishing a resisting blue belt are different results. JitsAI scores each technique against a nine-level ladder by partner size and experience, so you know who your heel hook really works on.
- One Focus a week, with pinned lessons from Henrique Rezende’s 74-lesson fundamentals course.
- A nine-level ladder for every technique, from partners less experienced than you to more experienced ones, each split lighter, same weight and heavier.
- Land it once and it’s a hit; 3 wins across 2 sessions and it’s proven.
$1 for 7 days, then $39 a year.
iPhone and Android.
Pick ONE thing One position for the week: an escape, a guard, a sweep.
Test it on everyone A quick check-in after class: who each round was against, and whether it worked.
Hit, then proven Land it once and it’s a HIT. Three across two sessions and it’s PROVEN.
Know what works See what holds up, against whom, then pick your next Focus.
Video transcripts
Transcript: What happens if you don’t tap to a heel hook
What happens if you don't tap to a heel hook your knee twists till the ropes holding it together tear They trap your hips and knee thighs pinned your heels the handle turn it and the shin turns with it The me takes the twist outside heel hook pinky toe side of your foot on that chest shin turns in Leg nearly straight first in the firing line the rope stopping your shin sliding forward the ACL Then the strap on the inside of your knee the MCL inside heel hook big toe side on their chest now The shin turns out that puts the back outside corner of your knee on the rack the outside strap the little anti-twist muscle your outer Hamstring tendon tear that corner right through and it rarely heals without surgery and your knee gives little warning before damage one survey over A thousand grapplers heel hooks came third for hurting the person caught leg trapped feel the twist tap early train tomorrow
Transcript: Why do heel hooks have such a scary reputation?
Why do heel hooks have such a scary reputation? Grab the heel and the foot becomes a handle. Turn it and the shin twists against the thigh. Big muscles bend and straighten your knee. The muscles that twist your shin are much weaker. In lab tests on healthy legs, they made roughly 30 newton meters of twist. Now the ligament. In 2008, researchers twisted donor knees until the ACL tore. On average, about 33 newton meters. Roughly the same. And a heel hook isn't one small muscle. It's your hips and your whole back turning that handle. Big caveat. Seven pairs of donor knees, twisted in a lab. Not a real heel hook. But the idea holds. Past what those muscles can resist, the ligaments take the twist. So go slow, train with people you trust and tap early. Next up, could you judo throw a gorilla? Yeah.
Transcript: What if you heel-hooked a gorilla?
What if you heel-hooked a gorilla? In episode 10, the heel-hook twisted the shin and the ligaments took the load. In donor knees, the ACL failed around 33 newton meters. Your shin-twisting muscles make roughly the same. Now the gorilla. Rough maths from dissections. Its arms carry three to four times a man's muscle, its legs under twice. The heel-hook goes after its smallest advantage. And unlike a throw, you don't have to move 170 kilos. You only have to turn one foot. But a bigger knee probably has thicker ligaments and nobody has ever tested a gorilla's. So the honest answer is maybe. Of everything we've tried, it's the only one that might work. Then you're holding the foot of a very awake 170 kilo animal. Thought experiment only. Next up, grip fatigue.
Heel hook questions
Are heel hooks legal in IBJJF?
Only for adult brown and black belts in no-gi. They’re illegal in the gi at every belt, in no-gi below brown belt, for masters, and in every kids’ and juvenile division (IBJJF Rule Book v6, 2024). Other organisations have their own rules.
What’s the difference between an inside and an outside heel hook?
The direction of the twist. The outside heel hook turns the shin inwards and mainly loads the ACL and the inner-knee ligaments. The inside heel hook turns the shin outwards and mainly loads the posterolateral corner, at the back outer side of the knee (Hasegawa et al. 2026).
Is the inside heel hook more dangerous?
Lots of grapplers believe so, but it hasn’t been shown. A 2026 review describes the idea as anecdotal and based on theory, not measurement (Hasegawa et al. 2026).
Do heel hooks always tear the ACL?
No. The outside heel hook loads the ACL; the inside heel hook mainly loads the posterolateral corner, and twisting the shin outwards barely loads the ACL (Markolf et al. 1995; Hasegawa et al. 2026).
Are heel hooks the most dangerous submission?
Not by the numbers available. In a survey of 1,140 grapplers, heel hooks were the third most common submission to injure the person caught, behind the armbar and the kimura (Hinz et al. 2021). That survey doesn’t say how often each submission was attempted, so it can’t rank them by risk per attempt.
Why does the heel hook have such a bad reputation?
Because it twists the knee, the knee gives little warning before damage, and some of the injuries are serious: complete tears of the posterolateral corner rarely heal without surgery (Chahla et al. 2016).
Sources
- Hasegawa et al. (2026), Common grappling submissions, Hawaiʻi Journal of Health & Social Welfare 85(6): 132–141. Outside heel hook: internal rotation of the shin, ACL then posteromedial structures at risk; inside heel hook: external rotation, posterolateral corner at risk; the femur must be pinned; “inside is more dangerous” described as anecdotal and theoretical.
- Markolf et al. (1995), Journal of Orthopaedic Research 13(6): 930–935. In cadaver knees, internal tibial torque loaded the ACL near full extension; external torque was a relatively unimportant mechanism for ACL force.
- Chahla et al. (2016), Archives of Bone and Joint Surgery 4(2): 97–103. Complete posterolateral corner tears rarely heal without surgery.
- Hinz et al. (2021), Orthopaedic Journal of Sports Medicine 9(12). Survey of 1,140 athletes: the heel hook was the 3rd most common submission to injure the person caught (27 cases, 11%), behind the armbar (55) and kimura (31).
- Piekarski et al. (2026), Sports Health 18(4): 890–897 (abstract). IBJJF brown and black belts, 2021: knee injuries 26.5 per 1,000 matches when exposed to the heel hook vs 2.2 unexposed (RR 12.0, 95% CI 1.5–96.1); no significant difference for the ankle. Cross-sectional; abstract only.
- IBJJF Rule Book v6 (June 2024), Technical fouls: illegal moves table, p. 29. “Heel hook” and “Locks twisting the knees” are illegal in every division except adult brown and black belt no-gi.
This page explains a sport technique. It isn’t medical advice.