The scapulae need to be able to both abduct and rotate laterally. If the scapulae are too “pulled down,” the spine will have to contort to achieve the entwined position.

Both the standing and the lifted leg need to internally rotate and adduct in this position.

To achieve the full entwining, the standing leg needs to flex at the hip and knee. This position of hip flexion with internal rotation and adduction is not structurally easy (the fibers of the hip joint capsule make it easy to internally rotate when the hip is in extension). The adduction with internal rotation especially gets to the piriformis. This position can be over-mobilizing for the knees; if the hips are too tight to achieve the actions, the knees can be focused to overrotate. This action is stabilizing for the sacroiliac joint.