The 3 Joint Rule is the key to effective arm drags, leg drags, and joint locks.
Arms and legs contain three major joints.
The human body is extremely adaptable, thanks to our three-jointed limbs. If an opponent has ever escaped your single leg by hopping all over the mat, you’ve experienced this firsthand.
This adaptability makes it pretty hard to control someone by grabbing their limb. Even if you can immobilize one joint, the pressure can “bleed” into the adjacent joints, allowing your opponent to bend and escape. That’s where the 3 Joint Rule comes in.
If you want to control a limb, you need to control at least 2 of the 3 joints. For example, if you want to arm drag someone, you need to control their wrist and their elbow. You won’t succeed with wrist control alone. This is why Aikido throws don’t work against a resisting opponent.
A submission requires control of all 3 joints in the limb. If your opponent is wiggling or rotating out of your submissions, this usually means you’re not controlling all 3 joints.
Summary of the 3 Joint Rule:
UPGRADE YOUR ARMBAR WITH THE 3 JOINT RULE
Let’s give a very specific example of the 3 Joint Rule in action: the armbar.
Finishing the armbar is a lot more nuanced than grabbing the hand and leaning back. Like any submission, the hard part is keeping your opponent immobilized so they can’t escape.
With the armbar, the main escapes you’ll likely see are:
In both of these scenarios, your opponent was able to escape because you failed to immobilize the shoulder.
This is an example of the 3 Joint Rule in action: you had control of the wrist and elbow, but because the shoulder was not immobilized, your opponent was able to either turn toward you (the bridge escape) or turn away from you (the hitchhiker escape). To prevent your opponent from escaping the armbar, you need to immobilize all three joints.