This is the classical yoga of Patanjali, 5000 years old. It is a form of Hatha Yoga or physical yoga with poses of varying degrees of difficulties, demanding increasing levels of flexibility, strength, balance and concentration. Mr Iyengar invented the use of props (bricks, belts, chair, etc.) used to help students with specific circumstances or limitations to achieve the best spinal alignment to maximize health benefits. From 1992, Mr Iyengar increased his focus on spinal alignment achieved through holding the asanas for longer, as opposed to quickly moving in and out of poses.
“Action is movement with intelligence. The world is filled with movement. What the world needs is more conscious movement, more action.” BKS Iyengar