Sit in vajrasana with the knees about 45 cm apart. The toes of both feet should remain in contact with each other. Lean forward and place the palms of the hands on the floor between the knees, with the fingers pointing towards the body. Straighten the arms fully and arch the back. Rest the body on the straight arms. Tilt the head back so that there is a comfortable amount of tension in the neck. Close the eyes and focus the inner gaze at the eyebrow centre, performing shambhavi mudra. The eyes may also be kept open, in which case gaze at a point on the ceiling. The mouth should be closed. Relax the whole body and mind.
In this posture there is a very definite extension of the spinal cord and the body is absolutely fixed.