Backbends are to be felt more than expressed. The other postures can be expressed and then felt. Like in meditation each person has to feel backbends.
B.K.S. IyengarOne day you too may experience what I have experienced. So right away go and practise.
B.K.S. IyengarExtension brings space, space brings freedom, freedom brings precision. Precision is truth.
B.K.S. Iyengar