Dave,
Thanks for reaching out, this is a great question. As it relates to stretching movement 17, just like you know to be true, the idea is start to gently rotate the entire body in small circles and engage the entire body equally as you rotate in those small circles. This movement is designed to simply help us learn how to rapidly move the entire body all together. Similarly to how an ice skater pressurizes and rotates his or her body when performing a 360 degree spin. The goal here is to rotate the whole body in tight small circles, shoulders moving at the same speed as the stomach, hips, thighs, shins and feet. That being said you will feel the toes grip the ground and the feet arch slightly to support each fast, circular movement. Work on really engaging the glutes, groin, and entire lower body to keep the lower body moving as if it is in a “body cast.” Almost as if the whole body is one solid piece moving in unison from top to bottom.