According to the Yoga Sutras of Patanjali, one of the ancient texts that is the basis for the philosophy behind yoga, there are eight “limbs” or paths of yoga. Each limb relates to an aspect of achieving a healthy and fulfilling life. Upon practicing all eight limbs of the path it becomes self-evident that no one element is elevated over another in a hierarchical order. Each is part of a holistic focus which is intended to bring completeness to the individual as they find their connection to the divine, whether they view the divine as a separate entity or something held within themselves (their 'highest' being). Only one of the limbs involves the performance of yoga postures or asanas.
In brief the eight limbs of yoga are:
1 Yama : Universal morality
2 Niyama : Personal observances
3 Asanas : Body postures
4 Pranayama : Breathing exercises, and control of prana
5 Pratyahara : Control of the senses
6 Dharana : Concentration and cultivating inner perceptual awareness
7 Dhyana : Devotion, Meditation on the Divine
8 Samadhi : Union with the Divine
In the Yoga Sutras, there is a concise definition of yogasanas : Sthiram sukham asanam meaning that 'position which is comfortable and steady'. Asanas are practices to develop the practitioner's ability to sit in one position without discomfort for extended lengths of time, as during meditation. Asanas ideally should cultivate a state of being in which you can remain steady, calm, quite and comfortable, physically and mentally.
Asanas can also be performed for curative or health reasons. By gently stretching the muscles, increasing blood flow and oxygenation, massaging the internal organs and toning the nerves throughout the body, the health of the practitioner can be wonderfully improved.
There are an infinite number of asanas, with certain practices focusing on specific postures or series of postures.
“However beautifully we carry out an asana, however flexible our body may be, if we do not achieve the integration of body, breath, and mind we can hardly claim that what we are doing is yoga. What is yoga after all? It is something we experience inside, deep within our being. Yoga is not an external experience. In yoga we try in every action to be as attentive as possible to everything we do. Yoga is different from dance or theatre. In yoga we are not creating something for others to look at…If we do not pay attention to ourselves in our practice, then we cannot call it yoga.” - T.K.V. Desikachar