Ura gyaku, inner wrist lock - Ninjutsu
Ura gyaku (裏逆), (אורה גיאקו) is one of the most important joint locks in Gyoku ryu. Ura gyaku is an arm lock that tears the extensor tendons of the hand, middle and index fingers. These tears might involve an actual fracture due to the weak structure of the small bones of the palm.
Video of Ura gyaku arm lock in Ninjutsu
Video tutorial how to do an Ura gyaku arm lock, basic
Video tutorial of Ura gyaku applied in sparring
Description of Ura Gyaku
The defender wraps the opponent's hand from above with the same hand (right hand to opponent's right hand or left grabs left). The defender's fingers grab the hypothenar eminence and peels it while rotating the hand. If done on the opponent's right hand it should rotate clockwise from the defender's perspective. If Ura gyaku is done on the opponent's left hand it should rotate counter clockwise. As this lock is relatively weak it should be accompanied with a strong pull or an elbow lock.
Image of Ura gyaku
This technique incorporates these attributes of Meta Perspectives: