Asana vs. Pranayama in Yoga ~ B.K.S. Iyengar, Astandala Yogamala vol. 3, pp. 102-103.

"It is true that I was paying more attention to back bends as they were spectacular. In 1958, for the first time, I made up my mind to do forward bends with chronological timings like back bends. The forward bends were giving more excruciating, sore pains than back bends. This sore and dull pain continued even after the practice for hours. The pain was of such a nature that I felt as if someone was hitting my back with a sledgehammer. This pain form forward bending made me live with pain, but in due course I overcame the pain and i do them with timings once a week even to this day. 

Forward extensions such as Janu Sirsasana began to help me keep the spine erect while doing pranayama. I learnt from this experience that back bends strengthen the inner muscles of the spinal column while forward extensions develop and strengthen its outer muscles. I could sit well and use the inner and outer muscles of the spine to run parallel to each other while doing pranayama.

This taught me a lesson that forward bends, back bends and lateral movements of the spinal muscles ought to be developed to tone the muscles of the spine as they act as a base for good pranayama. I realized how a balanced practice of asana is required to do proper pranayama.

 

“B.K.S. Iyengar, Astandala Yogamala vol. 3, pp. 102-103.