Yoga - Ustrasana

As shown in the figure, 

1. Sit on the knees,
2. Inhale some air and hold your heels/ankles with hands and
3. Raise your stomach and waist and bend your neck backwards. 
4. Remain in this position for 3 secs and 
5. Get back to the vajrasana position to relax.
6. Repeat this for 3 times.