Quote Originally Posted by HerbM View Post
No, the only way for "momentum to carry over" is for there to never be a stoppage nor a reversal which never happens from punch to punch (in typical punches.)

You throw a punch -- it stops -- you retract it. At the moment it stops all moment (in that direction) is gone. That's physics, and not very complex compared with the kinetic chains in the body that produce that initial momentum (e.g., multiple muscle applying force through multiple levers, the bones).

However when you retract a punch you can -- and should -- be retracting all the opposing muscles to the ones that powered the punch. Now, you can once again throw that punch with full power.

This is also one of the biggest reasons that 'staying relaxed' is so hard, and such an important method to increase punching power, but also why practice will improve your delivery so much if you put in thousands and thousands of really high quality reps.

They key: You must be able to release ALL the contractions in the opposing muscles while throwing the punch, then at the end of the punch extension instantaneously release the muscles powering the punch, and simultaneously contract the opposing muscles for retraction.

That ability to turn off and turn on the contraction is what you are training -- in addition to the perfect form of the punch and the exact sequence of turning on the chains of muscles while maintaining balance (other sets of muscles which must coordinate as your distribution of weight and changing momentum alter your static balance.)
I was wondering if there is a youtube video of a fighter who is very clearly using that method so we can see it in action.