This is one of the basic health Asanas. The position is to accent the chest and ribcage so that with the action of deep respiration certain physiological benefits are offered.
Benefits include better circulation and tonic affect on the heart, lungs, thyroid gland and kidneys.
It is a classic position to assist those with asthma and lung complaints in which case it is sustained for about 10 deeper breaths. As with all Asanas, a short period of relaxation follows.
Apart from a preventative purpose, the position can sometimes relieve an acute attack of asthma. Children will usually require some support and assistance.
There are several variations in positions of the legs and the arms as illustrated.