1. Start by standing in tadasana in the middle of your mat. You should be facing the long edges of the mat. Step or hop your feet and hands apart (ankles should line up with wrists). Press outer edges of your feet by drawing up on the inner ankles, make sure that the ball of your big toe is pressed firmly on the floor. Inhale and lift your chest as you take a slight pelvic tilt and look up.
2. Hands on your hips and exhale bending at the waist, making sure that your back stays parallel to the floor. When your torso is parallel to the floor press your fingertips onto the floor directly below your shoulders. Make sure your elbows are extended fully. Gently move your spine back into the torso so your back is slightly concave. Bring your head up and direct your gaze towards the ceiling (keeping the back of the neck long).
3. Draw the groins away from each other and take a few breaths. Maintain the concavity of your back and slowly walk your fingertips between your feet. After a few more breaths bend your elbows and lower your torso and head into a complete forward bend. Keep your torso as long as possible and if possible rest the crown of your head on the ground between your hands.
4. Your inner palms should be pressed actively into the floor with your fingers pointed forward. If possible walk your hands back until your forearms are perpendicular to the floor and your upper arms are parallel to the floor. Keep your back flexed by widening the shoulder blades; draw your shoulders down and away from the ears.
5. To come out of the pose walk your hands back out below your shoulders and lift and lengthen the torso. With an inhalation place your hands on your hips, pull your tailbone down and toward the floor, and bring your torso up. walk or hop your feet back into Tadasana.
In this asana you have a lot of muscular actions to consider. First, you need to draw the outer edges of the feet into the floor by drawing up with the inner ankles. You then need to engage the thigh muscles by drawing them up. Concave your back and flex your back by drawing the shoulders away from the ears. Lastly before getting into the complete position you must draw the inner groins away from each other. After this you need to walk your hands back keeping everything relaxed.