From Camel, inhale to raise the torso and sit on the ground in between your heels. Use your hands to pull your calves out of the way. If this hurts your knees, sit on the heels or sit on a block, and stay here.
Take a look at your feet and curl the arches around the curve of your bum so your toes are pointing behind you and slightly toward one another.
If it feels OK on your knees, shift weight back and bring one hand behind you and then the other.
Stay here or come to lie all the way down, flat on your back. Keep your knees as close together as possible to feel a deeper stretch in your quads.
Either rest your hands on the soles of your feet or hold opposite elbows above your head.