I'd have to disagree with the above. In my opinion, yonkyo is not a pain compliance technique. In fact, I don't think any technique in aikido relies on pain but on kuzushi or balance breaking.
Cas Long wrote in a different thread:
In my experience, Yonkyo proves more effective on the thinner, more tensile arm , & is more "difficult" to apply on an arm which is thicker.....this is because the technique relies on the compression of the radial nerve which appears closer to the surface of the first type of arm than the latter.
Sure, the pain part might be there, but it needn't be nor should it be relied upon. Better in my opinion to treat techniques like nikkyo and yonkyo as balance breaking techniques than pain-producing ones. The pain is just the icing on the proverbial cake in my mind...
I am having some difficulty understanding your post and was wondering if you could clarify for me.
First of all, I have read your quote of Cas Long's post and nowhere do I find any mention of the word 'pain', so I was wondering where you made the association?
I would also agree with you that it is absolutely necessary to take the Uke's balance to execute any
Having said that, I am wondering why ‘O'-Sensei would have spent many long arduous years codifying the techniques of Aikido into the specific groupings that we know today, if balance-breaking was the sole function and purpose of the techniques. After all, there are easier ways to unbalance someone than Nikyo or Sankyo!
A for-instance: In Kata dori, the Nage must move off the line to unbalance the Uke before even thinking of executing any of Ikkyo through Yonkyo, if they do not want to open themselves to possible further attack.
Once the Uke has been initially unbalanced, it is necessary to make sure that they stay unbalanced until completion of the movement (whatever that may be). It seems to me that the diversity of the technical movements must exist to teach the student various principles.
Yonkyo is the fourth principle of immobilisation, and pre-supposes a very firm grasp of the principles contained in Ikkyo through Sankyo.
The successful execution of Yonkyo requires good technique, because the immobilisation must be performed in a very precise manner.
On page 49 of ‘O'-Sensei's training manual Budo
it states in the note for technique 15. (Yonkyo):
"Placement of your (left) hand in this technique is as follows: hold the opponent's wrist tightly with both the little and ring fingers and use the knuckle at the base of the index finger to apply strong pressure to his pulse. (This is known as "Pin Number Four.")"
To reach this position and make the hand changes, it is necessary, in the basic forms, to pass through Ikkyo and Sankyo. This is because the pressure stimulates and compresses the radial nerve.
Once again, I have to agree with Cas in this respect, and it is interesting that ‘O'-Sensei states that we must use ‘ strong pressure'. The technique's definition is after all ‘Tekubi Osae' or wrist pinning or control.
The radial nerve wraps around the humerus in the radial groove. It runs anteriorly and divides into a superficial and deep branch. It is on the radial side of the arm, around the radius, about 5 cm upwards from the crease of the wrist, that the nerve is closest to the surface.
The turning of the Uke's forearm in both Omote and Ura variations serves to bring the nerve as far upwards towards the surface as possible, whilst still keeping Uke off-balance.
The pressure is then applied to this area (and sometimes in Ura variations against the outside of the radial bone) in a concentrated Ken-holding manner.
This maybe why the study of Aiki-Ken and Aiki-Jo is so necessary to Tai-Jutsu…but this is the subject of another thread!
It is of course necessary, as I have said, to keep the Uke continually off-balance, and the immobilisation must be completed as I think Cas said, in a three-dimensional movement, using strong co-ordinated hip turns.
The final pin should still maintain the pressure on Uke's forearm but also completes Uke's immobilisation on the mat through the shoulder, and ensures an inability to escape by a rotation of the hips to the outside. This is all based on the Yonkyo grab being in the Nage's centre-line.
I would say that 'pain' is a by-product of the technique being executed correctly. Since the radial nerve when found and pressured can be quite sensitive. Strong pressure can sometimes lead to a brief inability to extend the hand at the wrist.
Clearly though, depending on various body types, the nerve is sometimes hard to access and with forearm development through techniques like Nikyo, and the study of Aiki-Ken, can be all but impossible to find. As you have rightly pointed out, Yonkyo is still possible without ‘pain', so the complete form of the technique must be studied from the initial un-balancing right up to the final pin.
I would venture to suggest the you slightly misinterpreted the sense of Cas's post, since she spoke only of finding it difficult to locate the radial nerve and cause compression in certain body types and then went on to say that full use of the hips and body is necessary to complete the movement and un-balance Uke.
I think that the technique is designed to impart Ken holding principles through the holding pattern and the development of strong hip turns in the pin. ‘Pain' results when the technique is precisely applied.
I would draw all practitioners' attention to a quote of ‘O'-Sensei that appears in Morihiro Saito's Traditional Aikido Vol 4
on page 18:
"The Founder, however, strictly warned that 'a technique will lose its effectiveness unless it is delivered with perfect precision.'"
Only my thoughts.