Since Bhujang means a snake, this posture in which the body attains the shape of a raised-hood-stance of a snake, it is named so.
Method: Lie flat on your belly, on the floor. Now place your palms on the floor by the side of your trunk. Keep the elbows bent. Then, inhaling slowly lift the head and trunk-back upwards. Straighten your elbows by pressing the palms on the floor and raising the trunk. Then, exhaling, bend the knees and bring the legs in a perpendicular position to the ground. While exerting more pressure on right hand, remove the left off the floor and bring it back to clasp the left knee. Now, similarly bring the right arm back. Thus balanced on your thighs and pelvic region, pull on your knees and while exhaling increase the curve of your spine. Now, try to bring the back of your head and the feet in contact. Hold the pose for 15 to 20 seconds, then release the knees and come down to the floor, and relax.
This is a very rejuvenating exercise and cures whatever trouble is there in the back and shoulder region. This one asana does, by regular practice, wonder to the body. They say that the deposit of nectar is in the navel of man. But owing to the gravity-pull it goes down and gets burnt in the gastric fire. But in this posture, whole of the nectar permeates every part of the body. Those who regularly practise this asana remain young and virile till ripe old age.