Sthira Sukham Asanam (II/46)
Sthira = firm; Sukham = comfortable; Asanam = posture.
The posture should be firm, yet comfortable.
Once Parvati, the Divine Mother of the Universe, asked Lord Siva, the First Yogi, "How many Asanas are there in the World?".
"As many creatures in the Universe, so many Asanas" came the humorous reply.
The word 'Asana' in itself means a posture, a position of the body. When we add prefix yoga, then it has some meaning which will be elaborated, discussing this most important, most practical sutra.
Yoga is not mere Asanas. Yet, for most of the people all over the world, Yoga has become a synonym of Asana. If someone asks us, "Do you practice Yoga regularly?", he is equating yoga with asanas only. Well, there is no doubt, Asanas are an important Anga (limb) of Raja Yoga or the Astanga Yoga Of Patanjali.
But there are various ways of performing Asanas. Mainly, there are two schools of Asanas. First, the Hatha, the forceful way of performing, respectively, dynamic Asanas including Surya Namaskara. And, second, patanjali's way of performing Asanas slowly, in a relaxed way. In place of repeating the posture, the student is asked to maintain the posture for a long time.
It may be interesting to note that nowhere in his Sutras, Patanjali has mentioned the name of any Asana. He only tells us what should be our attitude towards Asana.
Patanjali's style of explaining a Yogic practice is unique. First, he would give us its definition, then the technique, the method and and in the end the result achieved through that practice.
In the light of this, let us understand first the three sutras about Asanas given by the great sage.
STHIRA SUKHAM ASANAM: The posture should be firm, yet comfortable. An Asana has yogic component only when it fulfills these two conditions. Then only it is a Yogasana. Otherwise, it is just a position of body.
Let us understand what STHIRA is and what SUKHA is.
STHIRA (FIRM): This is the first condition. The posture should be firm, without any movement, without any shaking. Suppose you are doing Ardha Chakrasan. And you are bending backward. In the final position ,if your body shakes or trembles,then you are not performing a yogasana.
Why does the body shakes? It is the language of the body. And we should be sensitive enough to understand language of our own body. perhaps you are bending more than your body can take it. So it sends the signals by shaking telling you that you are overdoing it.
To correct it, you should come back to a straight position and then again bend slowly till you reach a comfortable point.
Similarly if you are not balanced in Sarvangasana and legs are still unstable then your posture is not firm.
SUKHAM (RELAXED, COMFORTABLE): Patanjali is cautious. Some people have the tendency to stretch anything to an extreme. Just Because Patanjali has told the posture should be firm, they may strain too much in the name of firmness. The maxim followed in yoga is 'Na Hathat, Na Balat' (Nothing by force). Therefore, soon after using the word firm, Patanjali associated the important term Sukham. The very purpose of yoga is to relaxed, to be comfortable.
Now, this may look contradictory to some. How a posture can be firm yet comfortable, relaxed? Can STHIRA AND SUKHAM go together? It is possible if we follow the technique given by Patanjali in the subsequent sutra about asans.
But before we enter the next sutra, let us be clear about one thing. Patanjali is not concerned much about body. His idea to take us beyond body and also beyond mind. So, when he tells us to make our posture firm it is to achieve the firmness of mind.
Our mind is very fluctuating, chanchala. It can not be controlled directly. So we use indirect methods. One such method is to use body as a tool. By making body firm, we can achieve firmness of mind.
For example, there is a session of meditation and you are asked to sit in Lotus posture (Padmasana) or just with legs cross (Sukhasana). After a few minutes, in eyes closed state, you feel some itching or some fly on your body. You open your eyes and find nothing. The pseudo feeling of itching also vanishes. These itching sensations, imaginations of some fly or mosquito, are tricks played by mind.
Mind cannot keep quiet even for a while. And since mind and body are connected, it tries to move body also by playing such mischief.
If we understand this trick of mind and, using our will power, refuse to get disturbed, it learns to keep quite along with body after some time.
Thus by making the posture firm, we achieve the firmness of mind. That is why this path of Asana, pranayama etc is called path of psychic control. These practices help increase our will power.