This can be a bit hard to explain. In my technique book there are instructions for a Rumba Walk, mentioned is the body moving forward to a point of almost imbalance. Doing this with the feet not moving will bring your rear toe to its full height and more. Maintaining that high instep, even with the knee bending, as it moves into a neutral position. Pressure into the floor is a must. I find that after a few Rumba Walks I feel I might be getting there. But I must do it on every walk , the first step after the Fan position, all the way through into the Hockey Stick or Alamana. There is no time to wind up it must be done every step.There is also a hip movement there. That is why one of our teachers here used to say we should do as many Rumba Walks as a marathon runner does miles on the road. With a DVD I always zoom in to get a better look at the part I am studying. Here is a for instance. What does Paul Killick do with his arms on a Spot Turn.