I finally saw a chiropractor today. My sternum has hurt since Saturday morning to the point that just rolling over in bed was waking me up with sharp bolts of pain, I couldn't breath deeply or slump. I finally found out why (not how, which is still the $100 question). I popped a rib out of alignment. The Dr. thinks he got that squared away, but now he wants to take a better look at the curvature of my spine and try some in-depth treatments on that.