My very first introduction to pressure points was from my first martial arts school. We were taught the TW 3 point to facilitate a wrist grab release transitioning into a kotegashi takedown. This was in an International TKD school and it was part of the memorized kumite that we had. We were not told the name of the point, only that it was a pressure point. It was not a "pressure point" oriented school at the colored belt ranks.
In my humble opinion, this was appropriate. With or without the name of the point, pressure point use for tuite or grappling is fine and is probably taught somewhat incidentally or parenthetically in many schools, just as the TW 3 point was taught to me originally. The pressure points just loosen things up and help these maneuvers work better and I'd bet my next donut binge that there are a lot of excellent general martial arts practitioners out there who are using lots of pressure points for these purposes without necessarily being aware that they are doing so. They just put their hand "here" or put pressure "here" because things work better. Joints loosen, pain is instilled, leverage is better, whatever: things just work better.
In my present school, in the lower ranks, I was taught some pressure points for arm destructions, and some pressure points for grappling situations, again without a lot of attention to the name of the points. The pressure point use was inextricably connected to the best way to do the particular techniques. Again, many practitioners know these same things without there being a focus on it being "pressure point" related. We are taught to "Hit here, it hurts".
Now comes KOs- and this is where I take the pulpit. It seems a lot of people want to do KOs. They are fun to do. They are practical. The arguement in favor says that if you can KO an aggressor without harming him, and get away safely, you'll have less chance of a law suit, vs defending yourself by physically harming, permanently harming, or killing the perpetrator. You should not aspire or attempt to do KOs without instruction.
In my personal experience, I was required to be a black belt first before I could officially study Kyusho specifically and attempt approved KOs. I'm guessing that black belts were thought to be trustworthy enough to practice responsibly, to have the required striking skills, and to have the requisite karate skills for which the pressure point study would be helpful.
When my school joined Kyusho International, that changed a little. Under ranks could study Kyusho, but only via a very directed course of study and with close supervision by approved instructors. These pressure point/Kyusho classes were separate from the regular classes so that there would be some control for supervision and safety. Kyusho in general, and KO practice in particular can be dangerous.
My reason for this post is to respond to what appears to be a large number of young practitioners who want to learn how to do KOs with no supervision. Please don't. I regard Kyusho/pressure point study as an advanced refinement of karate skills that are already fairly well developed. Please if you are in the colored belt ranks, work with your instructor on what you should be learning and when. If you want to learn pressure points/Kyusho, find a qualified instructor. I recommend Kyusho International first because it works for me and I have confidence in the people. If you checked that web site and don't find anything near you, then try DKI, HKI, DSI, Rick Clark and other reputable people around the world. If you and a group MUST study alone, KI has a program for that. PLEASE!!! Do not study from youtube video clips or others, without some kind of organized instruction. Then use the forum to ask additional questions, to share ideas and results in addition to regular instruction.
The older I get, the better I was!