This article was appeared in Rock and Ice issue 203 (July 2012).
I’ve been battling posterior shoulder pain since about 2005. It’s an aching, hard-to-pinpoint pain all around the left scapula that builds gradually during a climbing session and is most noticeable during rests between climbs. The pain seems to be related to volume rather than intensity. I don’t experience pain every time I climb but it is more likely if I’m not taking two or three days off between climbing days. I’ve seen several PTs and orthopedic specialists over the years and have tried a host of shoulder-stabilizing exercises and stretches. An MRI showed an area of persistent inflammation around the supraspinatus. A steroid shot and physical therapy seemed to keep the pain at bay for several months but it has since returned.
For bouldering season I was able to minimize the frequency of painful sessions by always taking two days off between sessions. Now, however, even that strategy seems to be failing despite continued attention to shoulder-stabilization exercises and stretches.
—Edmclen, via rockandice.com
Chronic pain is like the sword of King Arthur, obstinately intractable unless you find someone with the right touch. I, of course, have that touch, and am more than willing to pull the sword of pain out of my fellow man. Unless you are wealthy, and then I ask just for a small Greek island.
Posterior shoulder pain doesn’t necessarily originate in your shoulder. That’s the most obvious answer to your conundrum, given that an MRI has shown little by way of a pain source. The area of chronic inflammation could be it, but it doesn’t sound like it can account for the volume of your pain. That said, it’s worth trying to strengthen that tendon with some eccentric supraspinatus exercises
Have the previous physicians looked at the possibility that the pain is coming from your neck? Is the pain worse when you are climbing or bouldering? If it’s worse on routes, the continual neck extension could be aggravating a disc/nerve root.
Scapula pain, for the most part, is a product of thoracic dysfunction. Teenage boys who have a disease called Shermans, which causes early degeneration of the mid-thoracic spine, have a particular propensity for your presentation. But either way, I would have someone look at you and determine whether you need some thoracic mobilization and strengthening. Get a set of thoracic x-rays.
Pain and mechanical dysfunction arising from the thoracic spine can easily cascade to affect the way your scapula moves, which could cause tendon issues at the shoulder, but they would be secondary, so treating them as primary is Band-Aid therapy only.