Breathe In = Nutation
Breathe Out = Counternutation
When the pelvis is weight-loaded from above in standing and upright seated postures, it moves in a specific way that is well-documented by orthopedic science. The top of your sacrum moves down into the center of your pelvis as your tailbone moves up. Your ilia, or hipbones, move toward each other. This causes your pubic bones to also squeeze together. Your ischia, or sit bones, move slightly apart. This movement is referred to as pelvic nutation.
You can feel with each in-breath that pelvic nutation is maximized as your lumbar spine is drawn all the way forward. Sense a slight tightening of your pubic bones and a widening sensation between your sit bones. You can discern for yourself that inhalation and pelvic nutation are a closely coupled, interdependent system. Your breath creates the shape and movement of your spine, pelvis and pelvic organs.
Counternutation occurs when your spine is slouched or your belly pulled in. The top of your sacrum moves up and out of your pelvic interior, while your tailbone tucks under. Your ilia pull slightly apart as do your pubic bones. Your sit bones move toward one another. Counternutation is closely coupled with exhalation. You must let all your breath out to pull your navel maximally toward your spine.
i love physical therapy: The importance of pelvic nutation - http://bit.ly/12u7yRE
Breath
