I am not asking about any diagnosis or cure I am wondering if anyone else has ever run into this before and if there is anything I can do to avoid it in the future. The day after boxing class, I awoke with the worst pain. It is directly under my right shoulder blade. The pain was so bad I couldn't take a deep breath. I think it is muscle related issue because my wife gave me an hour long back massage and I can at least breath today. (it still hurts) Has anyone else ever run into this before? Edit: I tend to only get this pain (sometimes) when I box. It has just never been this bad.