A great source for Yoga Postures by Mark Giubarelli.
Yoga Positions – Sirsa Setu Bandhasanasana
Translation: Bridge On the Head
Lying on the back place the hands down on the mat beside the hips. Bend the knees and take the heels quite close to the buttocks. Raise the pelvis and chest remaining grounded with the shoulders, neck, head and feet.
Place the hands beside the head. Allow the elbows to touch the mat. Raise up and place the head on the mat. You can roll slightly with the head so that you are on the upper front part of the head close to the forehead or even on the forehead slightly.
Distribute the weight evenly over the forearms, hands and head.
Take the heels of the mat and remain on the ball points of the toes. This will strengthen the ankles. Walk the legs back towards the head to increase the back bend.
Deep muscles in the spine are strengthened such as the iliocostal lumborum, longissimus thoracis, iliocostalis thoracisis. longissimus cervicis, longissimus capitis and the iliocostalis cervicis, spinalis thoracis. Muscles around the tibia are strengthened. These are the tibialis anterior, extensor digitorum longus and the extensor hallucis longus.
The stretch on the neck may be good for the thyroid. The use of the neck for support strengthens it as well as the shoulders.
Yoga Teacher Tips
Take more opportunities to raise onto the ballpoints of the toes in yoga poses. There are many poses you can do this in. It tones the muscles in the anterior lower leg and strengthens the ankles.