That's the beauty of backbends. Emotionally we can never be disturbed, for the emotional centre becomes an extrovert. When you do Viparita Dandasana, your head looks backwards, but your conscious mind stretches everywhere. Study by observing how the mind gets regulated. You not only know the freedom in the spine, but also the freedom in the spirit.
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.
In backbends, one touches the body physically, mentally, intellectually, consciously and spiritually everywhere.