Asana means a posture. According to one view, by imitating the posture of an animal, one can get that animal’s agility or any other special capacity. That is why quite a few yogasanas are named after some animal or the other (as in Kukkutasana or Mayurasana; kukkuta = cock; mayura = peacock).
Though such yogasanas can be innumerable, thirty-two have been mentioned as more important by the Gheranda Samhita, a standard work of Hatha Yoga, more directly concerned with the yogasanas and pranayama.
Yogasanas can be practiced by all, irrespective of age or sex or health conditions if specific instructions are followed. No external appliances are required. The yogic exercises reduce the toxins in the body instead of increasing them as done by the other exercise regimes.
Those who wish to practice yogasanas are required to observe some general rules. They are:
1. Organs of evacuation should be empty before practicing the yogasanas.
2. It is better to do the yogasanas after bath. Otherwise, there must be a gap of at least 30 minutes for bath after doing them.
3. Early morning is the best time for doing the yogasanas.
4. Drinking a glass of warm water before beginning will help.
5. The place must be clean and airy. A blanket should be spread and the yogasanas practiced on it.
6. Breathing must be done through the nostrils only.
7. Force or pressure should not be used, and the body should not tremble.
8. Lower the head and other parts of the body slowly; in particular, raised heels should be lowered slowly.
9. At the end, sweat should be dried by spreading it with the bare hands and not with a cloth.
Those suffering from some diseases like hypertension should not practice complicated yogic asanas. Women are advised to avoid some yogasanas during certain conditions.
Before beginning the regular practice of the yoga asanas, a few preparatory exercises have to be done to loosen the joints and attain flexibility. These include bending, rotating the arms, clenching the hands and movements of the neck. Some exercises for the eyes are also prescribed.
According to the Yogasutras of Patanjali asana is the third of the eight steps of yoga. He defines it as that posture in which one can sit comfortably and steadily for a long time, for meditation (vide 2.29, 46, 48). The works on Hathayoga recommend the following asanas for meditation: Bhadrasana, Padmasana, Siddhasana, Svastikasana, Vajrasana and Virasana.
These yoga asanas should be learnt from a qualified teacher. Though pictures and descriptions of them are often given in standard works, there is always a chance of going wrong or even getting into trouble.
When practiced properly yoga asanas have either cured or decreased the effects of many ailments. In fact, quite a few asanas have been prescribed as cures for specific diseases.