Muscle groups he mentions all have something to do with it based on the various positions you are in when punching...Interesting video...
Complex is correct...
Striking something solid, is what breaks the bone as a rule...Why the Karate punch is used striking objects as boards etc...
http://en.wikipedia.org/wiki/Punch_(combat)
When going to link, click on punch (strike)...
That particular tech or holding wrist in correct position will also assist with handguns that are very powerful (desert eagle) the grip will help or hinder some...
You must practice that fist and it takes time, wrapped hand should not apply (boxing wrap)...
****
Punching techniques in Karate are called tsuki or zuki. Contact is made with the first two knuckles (seiken)[12]. If any other part of the hand is used to strike with, such as the back of the fist (uraken) or the bottom of the fist (tetsui), then the blow is classified as a strike (uchi).
****
Translation for a complex language is the key...
Thanks,
Gary
