shoulder pain

Our user asked: "Hello, I lifted a heavy suitcase straight out of a cab trunk and later found I could not do my push ups with my right shoulder being very weak. I cannot raise my arm above chest level when held out straight in front of me. I can however, raise it above my head when lying on my back. I cannot stand and put my hair in a ponytail, brushing my teeth is hard with my right hand. I can raise it with my left hand lifting it, but there is no strength at all on its own. Thanks for any innput you may have on what I should do to excersise or if I need x-rays."