Start by kneeling down, then lean forward placing the elbows on the floor at shoulder width apart, bind the hands together in front of you, resting on the forearms and knees.
Extend the legs behind you, pulling the pelvis towards the ceiling, so your body is on a V shape, keep the feet hip width apart with the toes curled in. Hold this position for about 30 seconds, breathing normally.
To come out release the hands and sit down on your knees, lean the chest down towards the floor and rest on child pose for few seconds.
This posture helps to build upper body strength required for the headstand.
See also how to perform the Dolphin Push-up