Hi Quickstep
Just stepping back 2 or 3 posts, i agree completely about propulsion coming from the knee or thigh, as Ann Lewis apparently said (i don't have that tape), In fact i think it's obvious. Lowering will create energy, yes, but it would be almost impossible to dance without propulsion from the standing leg.
Makes me wonder how i dance tango (with little rise and fall) without using my standing leg for propulsion!!

Phil. When Michael Barr said that the Tango is a step step dance, and not a swinging dance It all began to make sense. No Rise or Fall. No Sway. John Wood said that feel as though you have a tail straight to the floor like a dragon. The weight very much to the rear. That was the example he gave. All the Best.

Great thanks for explanation especially the idea of why side step emphasized swing action , not be treated as a driving step.
I am practicing to acomplish turning lock to right following natural spin at one go .My teacher said : dance this 2 figures continuously with your strong ankles ,( He forgot I am 60 not 35 .) less flexed knee on 1, & , left toe slides forward as far as possible on beat 2, I felt a little bit panic for its farer distance based on limited flexed knees.( I will be appreciated if I may flex more knee, lower center , more propulsion generated, although the price is shorter line. ) Any way, I should overcome it if I want to dance better.
Ylchen