Yoga students often find it difficult to conceptualize the action necessary to stretch muscles along the spine. In order to stretch there must be two ends moving in opposite directions and that can’t happen if the two ends are not anchored.
The pelvis is anchored by the legs and the shoulders are anchored by the arms. The shoulder girdle and pelvic girdle are parallel structures and the arms and legs have to engage correctly to move the hips down and the ribcage up.
Teachers often ask students to move the shoulder blades to the spine but if that happens before the rib cage slides up it simple hardens the back and blows out the rib cage in the front. When the student draws the front ribs in against a hard back and compressed thoracic spine it feels like stuffing jigsaw puzzle pieces into spaces that are too tight.
My free spirited student Laura Miller who is featured in the video likes to spread her wings like a crane taking flight. It’s beautiful to watch as she moves toward a backbend but she can’t raise the ribs upward, only forward. In order to release the crane, Laura has to find the swooping forward and upward motion of her wings before she brings them back. In order to take flight she has to learn to coil the belly of the hamstrings and root the half moon of the heels down. Now she’s ready to soar.
No video can replace a teacher. This video describes a particular situation that a student deals with but there are other subtleties that are not described here for the purpose of simplicity.