(Salt Lake City, Utah, USA)
I was ice skating on December 1, 2014, and my toe pick caught on the ice throwing me forward and down. My arms were extended out and the brunt of it was on my left hand/arm. I broke the arm at the neck of the humerus bone. Three months out on disability, back to work in the 4th month, I began to have pain in the breastbone.
I've always had a breastbone that seems curved out, swollen I guess, up from my chest wall. My husband's sternum is flat. But now for the first time it is periodically painful. It hurts more at night, after I've been laying in bed on my right side. I still have trouble with my left arm and must keep it in certain positions to alleviate night-time pain. During the day it seems fine. But this breast-bone pain can be during the day, too. I rub it to try to get some relief. Upon palpation, the ache can extend leftward along the upper rib toward the shoulder.
Just prior to my injury, I got sick with sinus/bronchitis and was ill until January 23rd. Coughing hard and a lot. Then again in March, I was very ill and coughing, hard, again, for about 3 weeks. From what I've read about this, the extreme coughing can also cause this condition.
I'm going to mention this syndrome to my chiropractor next time I can go which will be in 5 days. And I'm saving this page. I'm also going to go to a massage therapist.
First, is it affecting the rib-sternum joint or the collarbone-sternal joint, the so called SC joint? Or both? With you having broken the humerus there would be a lot of stress on the SC joint.
Alternating iceblock and hot water in the shower on the joint helps, as does the massage you are doing.
My experience is that a heavy manipulation in the midback worsens this condition, but an "anterior thoracic" adjustment is far more effective. Your chiropractor will understand the terms.
Also, working all along the rib (or collarbone) from the spine to the sternum helps. If you cup your breast you can pull it out of the way so the treatment isn't offensive.
I hope it goes well. Getting out of bed is dangerous, but then most people die in their beds. Get back to skating!