“Hatha” Yoga really just means the physical practice of Yoga (asanas), as opposed to, say, chanting.
Through the practice of a system of asanas, it aims to unite the body, mind and spirit for health and well-being. This discipline is considered a powerful tool to relieve the stresses of modern-day life which in turn can help promote total physical and spiritual well-being
Iyengar Yoga is a form of Hatha Yoga, which focuses on the structural alignment of the physical body through the development of asanas.
B.K.S Iyengar pioneered the use of “props” such as cushions, blocks, and straps which function as aids allowing beginners to experience asanas more easily and fully. Props also allow elderly, injured, tired or ill students to enjoy the benefits of many asanas via fully “supported” methods.
There have been many studies performed on the effects of Iyengar yoga on patients with physical problems. In general, Iyengar yoga is useful in physical therapy because it assists in the manipulation of inflexible or injured areas. One study by Dr. Sharon Kolasins studied the effects of Iyengar yoga on symptoms of Osteoarthritis of the knees. The 11 participants attended a weekly 90-minute session for eight weeks in which they practiced Iyengar yoga. After the program, they had reduced pain and disability.