Good thought! Asana is that which promotes flow of integrated being! It's so actually a flow than a form. This follow the inverse law - what's External is opposite (Reflection) of Internal. Joints are "curved" space - Time in body. Thus the internal makes opposite in deeper level (mind). Thus Asana graduates to "Pratyahara", then to dharana, Dhyana & Samadhi (many to one to None). Each yoga (hatha yoga) limb is holographic in Nature. Like "Conscious sleep" it progresses ahead.