There are some exercice that ask us to raise our upper body but I can’t do it 😭. I am usually flexible and I can do many things but that’s impossible for me to raise my back. Why? I searched on google ( can’t raise my upper body and can’t raise my back) but I don’t have any results. I can’t do the same thing as the man in the pic. Does stretching my back everyday will help me to do that?