[usumoio]

I've studied Martial Arts for about 12 years. You're totally right. It takes years of training to learn how to properly throw a punch such that you harm your opponent and do not break your own hand.

[zarify]

And part of that is not attacking targets where you're likely to significantly injure yourself as well as your opponent. There's a lot to be said for not punching someone in the jaw.

[aResponder52]

and that part about the right way to hit different parts of the body.

a slap is almost as hard, and won't hurt the slapper.