I went to move my father 97 backwards while he was sitting down ,by trying to do it from behind him. I put my arms under his armpits and pulled under his shoulders.As a pulled back on him,my arms/hands slipped and instinctively I grabbed my hands in front of him and basically ended up doing heimlich manuver instead. I could swear I felt something shift by his sternum. He hollered that it hurt. He rubbed his chest by sternum area and said it is sore. I see him flexing his arms back and forth to flex his chest/ribs. Could I have broken something?