If the aim is to relax and gain optimum physical benefit from yoga practices, it is necessary to concentrate on something. By directing the mind to a specific region of the body or the breath, the effect of a particular practice is increased. Sometimes one of the chakras or psychic centers is also used as a point for spiritual concentration.
On a physical level, chakras are associated with the major nerve plexuses and endocrine glands in the body. Many asanas have a particularly powerful and beneficial effect on one or more of these glands or plexuses. For example, Sarvangasana exerts strong pressure on the thyroid gland in the throat region, which is associated with vishuddhi chakra. The thyroid is given a good massage and its functioning is greatly improved. However, if the concentration is directed to this chakra while performing the asana, the beneficial effects will be increased.
