Hi Scott – As someone prone to focus too much on small details, I really struggled with the first week of the program. I even spent a great deal of time listening to the anatomical descriptions and brushing up on my anatomy just to make sense of it all. Oy vey!! However, I found that as I progressed through the program, more and more pieces began to fall into place so that my understanding of the body mechanics solidified. With that said, I’m still a work in progress! Hang in there and know that “more WILL be revealed as you go through the program.” lol Accepting this has helped me be more patient.
I’ll go ahead and take a stab at answering your question. My understanding is that the feet, shins, legs, glutes, on up through your entire body will work together with everything starting from the ground up. As you advance through the program, more detail will be added about how to actually do this. Chapter 3 is where things really come together. But do take your time to master as much material as possible because this will establish a solid foundation on which you will build day by day.
Hope this helps in some small way.