Sarva Anga means all parts. This asana is said to bring benefits to the whole body. In order to perform the Sarvangasana properly you need some preparatory exercises that help strengthen the abdominal and lower back muscles.

Lie flat on your back. Keep the chin towards the chest so that you will feel the back of your neck staying firmly on the floor. Inhale and raise the right leg up perpendicular to the body keeping the toes pointing towards the head. Reach up with both hands and grasp the leg as high as you can. Bring the head up towards the knee. Then return the head to the floor and release the grasp on the leg. Lower the leg gently.
Repeat the exercise with the other leg. Remain flat on the back with your feet together and chin towards the chest. Get yourself ready for the Sarvangasana (shoulder stand). Take a few deep breaths. Inhale and raise both legs up to a right angle. Push the torso up gently until you are resting on the shoulders. Support the back with your hands bent at the elbow. Now your legs are over and beyond your head. The next step is to straighten the back as much as possible. Then relax the calf muscles and keep the knees straight and hold the position. Breathe deeply. To come out of the position lower the feet to a 450 angle over the head and bring the hands back onto the floor. Slowly and gently unroll the body to the floor and relax.

Effect: Gives a good stretch to the spine and makes it strong and flexible. Contributes to your health by improving blood circulation. Strengthens heart and lungs.