I entered into class late and saw everyone doing double positive circles. He instructed us to do it in a higher stance with our elbows attached to our waist. Shortly afterwards he wanted us to forget about our arms so we could focus on the lower body movements. Initially, the legs would pump up and down, back and forth, turning the waist much like a screw. A subsequent step required us to pump into the front leg, stretch the open the front kua to rotate the waist backwards. Following this Master Chen instructed a few of us individually to stick out the rear kua, connect it to the rear foot, press the rear foot into the ground as a means of rotating the waist to the forward position. Shifu pointed out to me that initially my rotation was on the top (chest). He demonstrated to me what he wanted me to do, which was to exaggerate the movements between the kuas to rotate the waist/dantien. For me, getting that up and down pumping motion, then emphasizing the use of the kuas in relationship to the feet and waist gave me the physical understanding how to be larger on the bottom than the top in a multidimensional manner.
In the end, what I think was achieved was dantien rotation through the process that I described. One of Master Chen’s concluding statements was “The movements of the body are in the dantien and never leaves the dantien. Only power gets out of the dantien”. Therefore, the lessons learned from the double positive circle lead to a much deeper understanding of the kua/dantian bio-mechanics and how it provides our source of taiji power in Practical Method.