I got a sharp pain in the center of my chest that feels like a pulled muscle. It goes away based on my position and posture . I notice that I get the pain when I stretch my arms back and when I bring my arms forward too fast I ll feel the pain. When I move my arms back or broaden my shoulders the pain goes away. No fever, no pain in left arm, no heavy breathing/ heartbeat . My concern comes from the feeling that it s not muscle but is bone/ cartilage related.