I'm having a bit of trouble trying to find the pressure point on the forearm with which to do yonkyo. Does anyone have any tips on how to find the right spot? I understand yonkyo doesn't necessarily affect everyone, but any insight would be appreciated.
Doesn't everyone have problems with this technique. It takes some persistence but given the nature of effective application, not something one wishes to train often.
Some words from me to help. Although words have different kinaesthetic interpretations for different people, but I will try.
Firstly, in order to achieve Yonkyo (a pressure point), one must essentially squeeze the nerve ending against the bone in order to achieve that pain response.
So, digging around in within the muscle and sinew is different for each opponent. Damn those thick wrist-ed people.
Firstly, I was taught to extend the index finger when applying the technique, this has the effect of pushing the knuckle forwards in the palm. Essentially your pushing the index finger joint into their wrist. So hand grasped but with the index finger bent backwards.
Two, when you are trying to break through the muscle you can try a type of wringing (forgive me - Chinese burn) type of movement. This one concept helped me a lot. So you are trying to get that knuckle from the middle of the wrist and turn it toward the outside of the wrist. You can move the nerve a bit to get it in the edge of the bone in the forearm (wrist) where there is less meat.
Finally there are a number of spots on the forearm where this works but easiest near the wrist due to the lack of flesh.
PS: Forget Yonkyo for real application as adrenalin will nullify this. Hope this Helped
I've applied Yonkajo (Yonkyo) in fights. Especially the lock in the end is really convenient because you can apply it standing up so you can easily get away and, if done correctly, it will only hurt when the adversary tries to get out, which is psychologically useful.
In my opinion the thing to get about Yonkajo is that while you can add a little bit of pain here and there, if you apply it properly and match uke's speed correctly, there's no pain. It's all about balance and correct positioning. Other people see this differently and I won't say they're wrong, it's a matter of emphasis.
As for "the" point. There isn't. If you're in the right position you can have the same control with the force passing through all of your palm instead of just that point. So don't focus on it too much. Focus on controlling uke's elbow. What you want to do is you want to end up in a position where your own wrist has maximal stability and where you can keep uke's elbow on the palm side of your own forearm (I hope that explanation makes sense). You apply it in any way where you can reach that position, and that depends on uke's balance. If, say, you apply it in the most common way, i.e. to the inside of the arm, you want to bend their elbow in a direction where they cannot resist (upwards or sideways, sometimes forward, always away from uke's body), and then once they have to move to adjust for that, you push their elbow further in the direction they're moving towards while turning your hands over and bending your wrist slightly in the direction of the palm in order to reach the control position.
Variations of that concept can be applied on both sides of the arm, but also to the ankles. I was looking for something different, but this video shows nicely how the concept can be applied to the outside of the arms and this video maybe illustrates how it's much more about balance than anything else.
I'm usually performing a yonkyo immediately after a sankyo.
I pull opponent's wrist up and twist it till it the tension is big enough (sankyo). Then I release my lock slightly, so that the opp's wrist un-twists and slides a bit down. Now this is the perfect staring point to apply a yonkyo!
The advantage of this method is, that you don't have to see what you are doing.
On a person with a normal pain treshold it works immediately.