BackGround:
Go means cow and mukha is face in Sanskrit. This pose resembles a cow's face when viewed from the back.  
Technique:
(1) Sit on the floor. Bend forward and raise the body, so its weight rests on the hands. Pass the right flexed knee over the left one.

(2) Sit on the left heel, resting the body's weight on it. The soles face upwards.

(3) Bend the right arm, raising the elbow high. Stretch your hand over the right shoulder, as far down the middle of the back, keeping the spine erect.

(4) Bring the left hand up the center of the back form below so that the hands meet. The palm of the right hand faces the back, and the palm of the left faces outwards. Look straight ahead.

Advantages:
As this asana expands the lungs, it is helpful for asthma, tuberculosis and other lung disorders, high blood pressure and mental strain. It is useful for piles and prostrate gland problems.