I don't understand what there is to "get" about that quote of yours.
It's a pretty basic, albeit it dramatic example of using (I'll use some fancy "internal" words for you) horizontal jing. I could go you one better then that and describe connecting to the ground to make upward force, or downward force; vertical jing.
The ground doesn't "make power", the ground only provides a stable platform to issue force from. There is a word for using it in ground applications its called "turning over".
Now if Dan would answer hafts question, all would be answered.
Sure it's basic, but that "basic" component is something 99% of people can't do. Kudos if you can, and my apologies if I misjudged you. I still have to disagree that top athletes do this kind of stuff.
The ground doesn't make power, I agree. It's more a metaphore.
OTAH, do have to agree with Dan that looking at the vids... whatever connections are in you or your students body aren't apparent.
A connected guy tends to have a different "look" when they move.
Course, if I'm wrong I'll be the first to man up and buy you a brew if we ever meet
I figured Tim would be using this stuff in his ground work though, I take it that's what he calls it?
Do you guys ever "torque" the insides to generate power?