Stevie Questions!!!

[portiab44]

So i am new to the ledge but i had a couple questions...I just saw stevie in atlanta on 3/24 and noticed she did not use her tambourine at all!! Also, she didnt even wear heels until the duets with rod stewart...my friend i went with is a doctor and she suggested she must have a back problem because even when she bowed her back was so straight...i thought it could be just a corset or something that comes along with her stage clothes...does anyone know whats going on? thanks!!