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.
B.K.S. IyengarLove begets courage, moderation creates abundance and humility generates power. Courage without love is brutish. Abundance without moderation leads to over-indulgence and decay. Power without humility breeds arrogance and tyranny.
B.K.S. IyengarPranayama teaches the aspirant to regulate his breathing and thereby control the mind.
B.K.S. Iyengar