Kneebar

Last updated: April 20, 2026

What is a kneebar?

A kneebar, sometimes written as “knee bar” or called a leg bar, is a joint-lock submission used across many grappling sports, including mixed martial arts, Brazilian jiu-jitsu, sambo, catch wrestling, and modern submission grappling events. The move starts with the attacker isolating the opponent’s leg between their own. From there, they pinch the knees together above the trapped knee joint and extend their hips to straighten the leg, keeping the heel close to the body. That extension drives the knee past full extension and tears at the ligaments behind the joint.

The kneebar exists because the knee, like the elbow, is a hinge joint with a narrow range of safe motion. Once it’s locked straight and pressure keeps coming, there’s nowhere for the joint to go. In MMA, the kneebar sits in a small family of leg locks alongside heel hooks and ankle locks, all of which give ground fighters a path to victory when they can’t get to the neck or the arm.

How the kneebar works

The mechanics come down to three points of control. The attacker needs to pin the opponent’s hip, clamp above the knee line, and hold the foot tight against their own torso. If any of those points break, the trapped leg slips free and the pressure bleeds off.

Once those three points are set, the finish is close in feel to an armbar. The attacker uses their hips as a fulcrum and bridges upward, driving the heel of the trapped leg toward the ceiling while the knee stays clamped low. The knee is forced past its normal lockout, and the opponent either taps or suffers damage to the ligaments and connective tissue around the joint. The Wikipedia leglock entry describes the basic pattern as trapping the opponent’s leg between the attacker’s legs, securing it with the arms so the kneecap points toward the body, and then applying hip pressure to force the leg straight.

Kneebar vs. heel hook

Most fans confuse the kneebar with the heel hook because both attack the leg and both can damage the knee. They are different submissions with different mechanics, different leg positions, and different injury profiles.

Feature	Kneebar	Heel hook
Attack vector	Hyperextension of the knee (straight-line)	Rotational torque through the heel into the knee
Target tissue	Ligaments and tendons across the back of the knee	Lateral ligaments of the knee (MCL, LCL, ACL)
Leg position at finish	Straight, locked out	Bent, with the heel twisted
Primary sensation	Pressure and stretch across the joint	Twisting pain radiating up from the ankle
Warning signs for the defender	Clear and gradual	Often late; damage can happen before pain
Typical injury if not tapped	Sprain or tear of knee ligaments	Major ligament rupture, often ACL or MCL

BJJ coach John Danaher, along with former UFC fighter Dean Lister, helped popularize the modern leg-lock game. Lister’s famous question to Danaher, “Why would you ignore 50 percent of the human body?”, is quoted on Evolve MMA’s breakdown of the submission and marked a shift in how grapplers approached leg attacks.

The kneebar in MMA competition

Kneebars are legal under the Unified Rules of Mixed Martial Arts, the ruleset used by the UFC and most American promotions. They are rare. A November 2025 Sportbible report put the number of kneebar finishes in UFC history at just 16, which makes the submission one of the least common finishes on the books.

Two kneebars stand out. The first is Frank Mir’s submission of Brock Lesnar at UFC 81 on February 2, 2008, in Las Vegas. Lesnar, making his UFC debut, was dominating with ground and pound before a referee stoppage for strikes to the back of the head reset the position. Mir locked up a kneebar from the guard and forced the tap inside the first round. The finish remains one of the most referenced submissions in UFC heavyweight history and was Lesnar’s first professional loss.

The second is UFC 228 on September 8, 2018, the only card in UFC history to feature two kneebar victories on the same night. Zabit Magomedsharipov submitted Brandon Davis at 3:46 of the second round by rolling into the finish from back control, as recorded on Davis’s official UFC.com athlete page. Earlier on the same card, Aljamain Sterling locked in a similar back-take kneebar on Cody Stamann.

Other notable kneebar finishes include Ken Shamrock’s submission of Bas Rutten in a 1995 King of Pancrase title fight, which BJJ Fanatics described as a foundational moment for submission grappling in professional fighting, and Ariane Lipski’s 2020 finish of Luana Carolina on Fight Island. According to Sportbible, Carolina heard three pops in her leg during the submission and missed ten months of action with ligament damage, footage that prompted calls from some fans to have the technique restricted.

Origin and history

The kneebar is old. The Wikipedia entry on leglocks traces leg attacks back roughly 2,500 years to pankration in the original Olympic Games. Its closest modern ancestor sits in judo, classified there as hiza-juji-gatame. Judo eventually banned leg locks from competition because of the injury risk, but the technique survived in other grappling systems.

Sambo, developed by the Soviet military in the 1920s, became the art most associated with aggressive leg attacks. While early Brazilian jiu-jitsu largely avoided leg locks, sambo practitioners drilled them as a primary submission category, and catch wrestlers carried their own lineage of the hold.

The modern rise of leg attacks in BJJ and MMA came through coaches like Renzo Gracie black belt John Danaher and his competitive team, who built entire systems around kneebars, heel hooks, and other attacks from the ashi garami family. That shift changed the kneebar from a rarely-trained curiosity into a core part of the grappling game.

Variations

Several recognizable forms of the kneebar appear in competition.

The standard kneebar is the armbar-style finish, with the attacker belly-up or belly-down and the opponent’s leg extended between their own legs.

The rolling kneebar is entered from standing, often off a caught kick or a scramble, by rolling forward and trapping the leg mid-motion.

The Suloev Stretch, named after Russian fighter Amar Suloev and described in Wikipedia’s leglock entry, is a variation of back control where the opponent’s ankle is pulled toward their own shoulder, stressing the hamstring and hyperextending the knee at the same time.

Kneebars finished from the 50/50 guard and from back mount, like the Magomedsharipov and Sterling finishes at UFC 228, have become more common as the leg-lock game has evolved.

Frequently Asked Questions

Is a kneebar legal in the UFC?

Yes. The Unified Rules of Mixed Martial Arts allow kneebars at every level of American MMA, including the UFC and Bellator. ONE Championship also permits them under the Global MMA Ruleset.

Is a kneebar legal in BJJ?

That depends on the ruleset. Under IBJJF rules, kneebars are legal only for brown belts and above, while submission-only promotions like ADCC and Polaris permit them at every belt level.

How dangerous is a kneebar?

Applied slowly in training, a kneebar is no more dangerous than an armbar and gives the defender time to tap. Applied fast or cranked, it can tear the ligaments and tendons around the knee, which can mean months of rehab or surgery.

What’s the difference between a kneebar and a heel hook?

A kneebar hyperextends a straight leg. A heel hook twists a bent leg and tears the ligaments on the side of the knee through rotation.

Why are kneebars rare in MMA?

Setting up a kneebar usually requires the attacker to give up a dominant position. Most fighters would rather stay on top and strike than dive for a leg, so the submission mostly shows up in scrambles or when a grappling specialist makes it a focus of their game.

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Sources

1. Wikipedia. “Leglock.” Accessed April 2026.
2. Wikipedia. “UFC 100.” Accessed April 2026.
3. Wikipedia. “Frank Mir.” Accessed April 2026.
4. Wikipedia. “Ude hishigi hiza gatame.” Accessed April 2026.
5. UFC.com. “Brandon Davis, Athlete Record.” Accessed April 2026.
6. Heavy.com. “Explaining the New MMA Rules That Debuted at UFC Edmonton.” November 2, 2024.
7. Sportbible. “UFC Submission Used Just 16 Times Is So Brutal People Want It Banned.” November 13, 2025.
8. Evolve Daily. “Kneebar Explained: How To Do A Kneebar In BJJ.” Accessed April 2026.
9. BJJ Fanatics. “Knee Bar BJJ.” Accessed April 2026.
10. Bloody Elbow. “UFC 228 Results: Zabit Magomedsharipov Submits Brandon Davis With Kneebar.” September 8, 2018.

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