This technique is used when the opponent tries to grab the defender's wrist.
Start off in the Aikido stance. Allow the opponent to grab your wrist.
The opponent, in this picture, grabs your right wrist with his right hand.
Use your left hand to hold the opponent's right hand in place. Make sure you cover enough
of his/her hand so that the opponent cannot get away.
With your right hand make a circular motion around the opponent's right wrist.
This might start to sound a little confusing, but if you take it one step at a time
there should not be a lot of trouble.
While you make the circular motion, remember that you are trying to get the right side
of your palm to pass the right side of the opponent's palm.
Move your hand around the opponent's wrist. Using your fingers grab the opponent's forearm.
If the above video does not appear properly click the following link...
Watching a video might help you better understand the motion.
After you manage to get your hand around the opponent's forearm close to the base of the palm,
hook your hand on, and grip the forearm so that you have a good, strong hold.
Let examine what happens to the human bone structure while applying this technique.