Hi Ronin

I think it's quite commonplace with a plethora of different names nowadays like 'waveform' or just 'close quarter'- it can be done in a variety of ways and in taiji we suspend our bodyweight in the muscles and tendons and lightly pump the energy system of the body from the feet, through the legs and then give a light 'shrug'to the waist and shoulders to assist power. As long as you stay tension free and allow the energy you generate to flow the punch can be highly effective.

It's also one of those things that the harder you try, the worse it gets.