I've been thinking a lot about all the techniques people run around learning, and I find more and more that I'm not interested in learning new techniques. All the new techniques boar me to sleep. I'd much rather study an old technique again and get a better understanding of the principles within it. So I wrote this blog about it.
Thanks for the nice video. Up and Down looks very clearly. This kind of movements are also seen in other arts too and very universal. I think this is the secret atemi that many shihans use. IMHO, the question is how to do it without bending or un-bedning knees.