When viewing the video, note how flattening the back moves the origin of the piriformis on the sacrum further away from its insertion on the femur, thus accentuating and refining the stretch. This is an example of lumbar-pelvic and femoral-pelvic rhythm. The last section of the video, where we have digitally hidden one half of the pelvis to expose the movement of the sacrum, illustrates this concept. Learn more about joint rhythm in our post “Preventative Strategies for Lower Back Strains in Yoga.” -http://www.dailybandha.com/2012/01/preventative-strategies-for-lower-back.html
