It can be assumed that Yogasana has been practiced in an undeloveped & primitive form since the creation of mankind. The children are in savasana immediately after birth. Then gradually they start using their body parts as needed. The most they move their limbs , the more their physically development takes place. They live in the state in which they get physical comfort & pleasure.
Human development has been going on like this since early times. From that, gradually their physically development as well as mental intellectual development also took place. After that Yogasana began to develop through many different methods. For example children yawn, pull their limbs even in their sleep. Similarly people of other ages do physical actions like yawning, stretching, turning the body right & left, snapping fingers, turning the head as soon as they wake up. Such action happen yesterday, tomorrow and will continue. Any creatures comes to this earth in savasana and leave again in bantya through savasana. The difference is that the mind comes in child state and goes into an old decrepit state.
There can be no doubt that since human being is more rational than all other creatures, it has been developed as a worker. In the old books & Upanishads & other texts after the creation or writing of the scripts where yoga is mentioned. After understanding and getting the benefits from this various sadaks have been doing sadhana and they have been freed from many types of diseases& are healthy and living long lives. Those who practice yoga are still healthy and long lived.
Yogasana development has been going on since the time of lord Shiva and Parvathi whom lived in Kailash. It is said that Shiva & Pārbati practiced tandava & lasya dances as well as Yogasana in order to get the life force that could be mix with air and water of Kailash. It is during this development that yoga is being propagated in the world today.
The development of Yoga as natural medicine can be seen everywhere in Nepal & Neighbourhood country India. The word “ Yoga” is derived from Sanskrit word Yuz’ with suffix ‘a’. It means connecting two or more objects, words or body & mind. Yuz+A=Yoga. The word “ YOGA” is formed ‘YU’=YO & J=C.
Some people consider yoga as a science , some consider it as an art of staying healthy, and some consider as its as means of harmonizing the soul and the divine.
Asana generally means sitting in a position for long time with happiness or joy. It is the cornerstone of any practice. Sadhana cannot be successfully without it. Whatever sadhana is done by any caste and person of the world , be it physical or spiritual where they need asana to achieve their goals. In the same way, posture is also required in yoga practice just a fish needs water to survive, so does asana for meditation.
Asana is the physical body & within it is the mind and soul. From the soul leaves the physical body turns into a corpse. It is his farewell for ever.