First yoga deals with health, strength and conquest of the body. Next, it lifts the veil of difference between the body and the mind. Lastly, it leads the Sadhaka to peace and unalloyed purity.
I also say with backbends, you have to be cautiously bold. Not carelessly bold. You have to descend to the dictation of the spine. You cannot command from the brain to do the poses. As you play with a child, guarding the child from injuries, similarly you have to play in backbends, guarding your spine.
