Understand juji-gatame: rules, tapping and learning path in judo. Deliberately without a how-to, because this armlock belongs under a coach's supervision.
The honest answer: juji-gatame is the best-known armlock in judo, and exactly for that reason you deliberately get no how-to here. An armlock attacks the elbow joint. Whoever applies it wrongly or jerkily injures people. This guide explains where the armlock stands in judo, which rules apply, what the learning path looks like in a club and why tapping is the most important skill. You learn the technical execution exclusively from a coach, on a partner who knows the rules.
The German Judo Federation lists juji-gatame in the basic programme and requires it at 4th kyu, together with ude-garami and a third armlock of free choice [3]. That is a level for the more advanced with mat experience, not for the first month. How long you need to get there is individual. That is a practical rule of thumb, not a study.
Before you learn any armlock, you practise tapping: both partners tap at any pressure immediately, take the tension out and release. The DJB calls it the universal STOP signal that ends all actions immediately [3]. Milestone: you release reflexively as soon as your partner taps.
You master holds and escapes. The DJB intends children to learn a comprehensive repertoire of holds and escapes in their first years before armlocks or chokes play a role in randori [3]. Milestone: you hold partners under control and release when needed.
From 5th kyu the DJB requires you to learn defensive behaviour against armlocks [3]. That means: you learn when to tap early, how to protect the arm and how to free yourself. Milestone: you recognise the danger position and react early.
The coach shows you the technique slowly, you see the principle: the elbow joint is extended. In judo the elbow is the only joint on which an armlock is allowed [2]. Milestone: you can explain in your own words which joint is affected and why.
Only when your coach gives the go-ahead do you practise with a partner and supervision in small steps. You never build pressure jerkily but so slowly that your partner can tap at any time. The judo culture in the rules names it as the core: at the elbow, the opponent must be left the possibility to give up [1]. Milestone: your partner taps before pain arises and you let go immediately.
The elbow is no harmless joint in judo. At the 2012 Olympic Games in London, judo and weightlifting together contributed nearly half of the elbow injuries examined by imaging [6]. In 21 years of French competition surveillance, women had higher rates of elbow dislocations than men [4]. After conservatively treated simple elbow dislocations, 69% of the affected judoka in a European survey returned in under three months [5]. These are numbers that show how seriously the joint must be taken, not expected values for you. So: armlocks only with a coach, only with a partner who knows tapping, on tatami and under supervision, never in play, never jerkily, never against partners without knowledge of the rules. The DJB notes that children often need five to six years before they may apply armlocks or chokes in randori or competition [3]. This guide explains and motivates, it does not replace supervised training.
The strongest training for juji-gatame is training against it: learn as uke to tap early and protect your arm. Whoever understands the defence controls the armlock better later. The DJB prescribes that all skills are learned in both roles [3]. Whoever can tap safely can apply safely.
In the programme of the German Judo Federation it is mandatory at 4th kyu, next to ude-garami and one further armlock [3]. Before that come breakfalls, throws and holds.
Yes, but only on the elbow and from groundwork. Standing without a throwing technique it is shido, locks on the shoulder lead to hansoku-make [1][2].
It can injure the elbow if applied jerkily or against resistance without tapping. The safe rule is: slowly, controlled, release immediately when tapped.
This guide deliberately gives you no how-to. Videos replace neither a coach nor a partner who knows the tap rule. Learn the armlock only in a club.
Kami-shiho-gatame: How to Hold the Upper Four-Quarter Pin in Judo