George S. Ledyard wrote:
Also, Mary Heiny Sensei once told me that the extension movement should be done explosively with the energy of a strike.
I would absolutely concur with this statement. Both the forward and reverse movements are very relaxed, and very explosive. When you can get a good grasp of this, you can then proceed to understanding the third movement, which is explosive in both directions. However, I want to stress that there is a relationship between the forward and backward movements here, in that like a sign wave, with no beginning and no ending, there is a connection. In essence I mean that it is really one movement that is based upon a connection between the breath and the rotation of the wrists. Moving towards actual application, this is when one develops the Ryu/Circle/Nagare/ techniques that we see many practice, yet seem so ineffective.