Janu Sirsasana A, or 'Head to knee pose A', is the tenth posture in the Primary Series of the Astanga Vinyasa yoga system. A forward bend for all levels of students, Janu Sirsasana is also a spinal twist.
The Primary Series is said to be the most demanding because it is the first series you learn as a beginner - and every beginning is hard. It is called Yoga Chikitsa, meaning Yoga Therapy. It is a series for cleansing and healing the body.