Thanks for the replies. Sure helps a bunch.

It seems in regards to the back foot, the rear foot advances and plants as the lead arm in returning just prior to the back hand firing. So it would be: push off the rear foot, front foot advances as lead jab is extended, lead jab returns to guard as rear foot in moved/slid forward with the initial push, rear hand is extended to complete the combo as the rear foot stops and plants. For some reason I always wanted to move the rear hand and foot in unison, but power and balance was off.

I think I now understand the mechanics a little better with the hands/feet coordination.

Thanks!!