Poorna Supta Vajrasana -- Diamond .. In this posture the whole spinal column toned as the fresh blood is made to circulate. The chest expands fully..It is a wonderful back bend posture .. make entire back strong and flexible. But this posture is also very difficult to master. In the beginning you may not be able to catch hold of the feet. You can use a belt to begin with. Gradually you can catch hold the feet with out the aid of the belt...

The step by step instruction is shown below...