Shirshasana is a posture in Yoga. Shirsha here means the head. This asana is called Shirshasana because in it one stands on one’s head. It is not found mentioned in any authoritative text of Yoga. However a description similar to this pose is found in Gheranda Samhita (III.30) and Shiva Samhita (IV.69) under the name viparita karani mudra. It is one of the popular postures of Yoga, and a person who can stand on his head is supposed to be an expert in Yoga.
Shirshasana is performed by keeping the topmost portion of the head on the ground on a soft cushion, prepared by folding a sheet of cloth, with the hands kept supporting the head from behind, with the fingers interlocked; the elbows are kept on the ground comfortably apart, making an angle with the forearms, which is neither too narrow nor too wide. Then, brining the knees near the chest and raising the hips, the back and thighs are made almost straight in an inverted position and the feet are lifted with a slight push. Keeping the knees folded, the body is balanced in a straight line from the neck upward as far as the knees. The back is slightly arched to maintain balance. When balance is established in this position, the knees are unfolded and the topsy-turvy pose is held straight without shaking. There should be no bend at the neck. This position is maintained for ‘n’ number of breaths. While coming back to the starting position, the knees are folded and lowered, and then the thighs are lowered, keeping the knees on the ground. Then the head is raised from the ground.
Due to the inverted position, the asana promotes venous blood flow towards the heart and the legs by the force of gravity.