Back to the OP : Thanks for posting your training thing. Can you do it with the (Jeremy) guy in black not falling down? He could just take a step back instead then you can get more sessions in before he gets tired.
What John said, you really need solid resistance all the way through the movement to get the feedback you're looking for. Besides, as you can tell from our, er, physiques, we could probably use some more falling down and getting up in our lives...