I often have pain which can all at one time or having a starting point gradually spreading. The pain feel like a muscle pain of spasm. It occurs mid back between shoulder blades, under armpits acoss top part of chest(top of breast and sternum). It will last couple of weeks and go away until next time. One dr. thought it to be originating in neck, chiropractor said top rib pinching nerve. Chest pain is not heart related, same deeply bruised feeling as when I either cracked of damaged sternum. First occurrence was about 4-4 1/2 yrs ago. I ve had neck x-rays, not the problem and nothing else. Just take Naproxin. What might actually be causing and what test will identify cause for certain?