Although many forms of yoga training have existed for thousands of years, Hatha (the yoga of physical mastery) is a relative newcomer in comparison to the other main systems of Yogic methodology in India. Hatha dates back as recently as the 15th century with Svami Svatmarama and is the base for many popular styles today such as Iyengar, Bikram, Kundalini, and Ashtanga.
This lecture from Aura Wellness Center's 200 hour yoga instructor training intensive addresses the therapeutic applications of half chair pose.
Depending on the Yoga school, posturing, alignment and adjustment can be an extremely important part of one's training. A typical 200-hour Yoga teacher training course may spend over 100 hours focusing on the alignment of asanas.
What is the purpose or value of asana? Many Yoga teachers do not read or understand the writings of Maharishi Patanjali. This leads to the erroneous assumption that asana is just a physical exercise to improve circulation, increase bone density, and develop good muscle tone.