Gulfangushthasana, Heel to toes pose
Lay in Supta Samasthiti and check from which nostril you are breathing. If it is the right nostril, place your right heel in between the big and the first toe of your left foot. Grab your right heel with the toes of the left foot and while you keep on lying straight, you lay both feet to the right side.
Count until ten, then bring them up again and place your right foot back to the floor.
Repeat the exercise with the other leg.
Gulfangushthasana, as basic as it may seem, is a very effective exercise. It is good against lower back pain, slip disk problems, sciatica pain and even malposition of sacrum and hip.
Additionally to these benefits for your back, it is good for your ligaments and ham strings which get stretched in this yoga pose.
The muscles of your feet and calves also get unusual exercise and thus become more and more flexible.
While you are in the yoga position, focus on the twist in your pelvis and feel how your ligaments and muscles are stretched.
Keep your body as straight as possible.