Yonkyo
四教
Literally: fourth teaching
Also known as: yonkajo osae, kote osae
Aikido control in which tori grips uke's forearm with both hands and presses the radial nerve rather than levering the joint.
Quick Facts
⚠️ Common Mistakes
Common mistakes: gripping the forearm with the fingers instead of pressing with the bone, hunting for the "right spot" by squeezing, and relying on the technique working on everyone — it does not.
💡 Key Tip
Do not hunt for the point with the fingers. The pressure comes from the bone at the base of the index finger and from body movement.
About
Yonkyo (四教), literally "fourth teaching," is an arm control in aikido, also called kote osae ("forearm pin") or yonkajo osae. Tori grips uke's forearm with both hands and presses the knuckles from the palm side onto the radial nerve against the ulna's periosteum. Aikido Journal describes how the pressure on the nerve point on the underside of the forearm brings the attacker into an immobilizing position. In how the shoulder is led, yonkyo resembles ikkyo. The difference is that ikkyo levers the elbow and wrist and presses on the ulnar nerve, while yonkyo works both hands on the forearm and targets the radial nerve. Under the Aiki-LA club's grading syllabus, which follows Hombu Dojo, it is tested from 5th kyu.