Headstand and scorpion advanced variations. Shirshasana, also spelled Sirsasana, and Vrikshasana increase balance, concentration and peace of mind. These Asanas are performed by Narayani, coauthor of "Sivananda Companion to Yoga", advanced Yoga practicioner and Yoga Master based in London. Without explanations - you can learn by doing. Narayani is one of the most popular teachers at Yoga Vidya Ashram Germany.