Hadaka-jime (naked choke) is the judo rear naked choke, done with the arms alone and no grip on the judogi. Tori is behind uke with a forearm across the front of the neck and squeezes while bringing uke's head forward. It is the same movement as the BJJ rear naked choke or mata leão and one of the most effective chokes there is. That is exactly why it has to be trained under close supervision.
The two forms of hadaka-jime
There are two ways to tighten it, and they do not feel the same to uke.
The classic Kodokan form puts the blade of the forearm against the front of the throat. Both hands clasp above uke's shoulder and tori drives the head forward with a shoulder or cheek. The pressure is on the windpipe. It hurts and uke taps fast, but it is easy to injure a partner by squeezing too hard.
In the form everyone now calls the mata leão, you put uke's neck in the crook of the elbow. The choking hand grabs the biceps of the other arm, and that second hand goes behind uke's head. You squeeze the elbows toward each other. The pressure is on the sides of the neck: a blood choke, faster and less painful.
Our view: teach adults the second form. It is safer for the windpipe and more effective. The first is still worth knowing because it appears in the katame-no-kata.
Placing the forearm
One detail decides everything. Your elbow must be centered under uke's chin. Elbow off to the side, you squeeze the jaw and nothing happens. Forearm too low, you crush the collarbone.
Press your chest into his back and your cheek against his head, on the side opposite the choking arm. The tighter you are, the less room he has to tuck his chin. Breathe and tighten gradually. Never jerk it.
Where it comes from
In judo, hadaka-jime mostly shows up in two situations:
- Uke is turtled and you are behind him. You slide the arm under his chin while he guards his lapels. It is often chained with a turnover to put him on his back, hooks in.
- You sit behind uke with your legs around his waist. That is the position BJJ calls back control, covered in the article on BJJ back control.
Uke often guards his collar with his hands, and that is why hadaka-jime works so well. He is protecting the jacket, not the neck. When he guards both, switch to okuri-eri-jime, which uses the lapel and goes around the hand.
Safety comes first
Blood chokes can put someone out within seconds. Any well-run dojo enforces these rules:
- uke taps twice or says "maitta" (I give up), and tori lets go at once, with no last squeeze;
- chokes are never trained without a coach on the mat;
- nobody resists "to see what happens": if it is tight, tap;
- beginners practice the setup without squeezing for several sessions.
If a partner passes out, release, lay them on their side and alert the coach. Get medical advice afterwards.
What the rules allow
Hadaka-jime belongs to the shime-waza, the chokes of judo. Chokes are banned in the youngest age groups and become legal from an age set by each national federation, which also decides any intermediate restrictions. Some ways of choking stay illegal at every age, and the page on illegal techniques in judo lists them. A tap or loss of consciousness scores ippon.
Training it without hurting anyone
Drill the entry, not the finish. Uke turtles and protects the neck with both hands. Tori has thirty seconds to slide the forearm under the chin without squeezing. Once the forearm is in, stop and reset. This builds the skill that is missing in randori, which is getting past the defending hand. Squeezing is the easy part.
Against the turtle, the other weapon is sankaku-jime. The gokyo page shows how the Kodokan organizes the standing half of judo next to this ground work.