Originally Posted by Boxing>MMA
^^^^^ You are sadly mistaken on what they are telling you. NG is saying the flow of energy comes from the the (energy increases on how fast you do this) ground to the foot to the legs which then carried to the arm which size, strength, grip, and speed increase the energy which equals force out. I know other factors play a role just making a close example to reality.
Nonetheless, the point remains -- the power of a punch comes from more than the arms. In fact, you could have some really strong muscly guy punch with ONLY his arm-strength, but without utilizing his legs, his hips, and shoulders he tiny little shrimp with good punching technique could pack more oomph. And while I do agree that powerful/fast arms do help, I still would say that they're secondary.