Sorry to hear about the shoulder.
Last Friday night I was helping my neighbor move an upright freezer full of frozen food up onto his deck. We were using a basic two wheeled hand dolly with no strap. As we started getting the thing up over the edge of the deck the damn thing shifted to the right and started to go over. My natural reaction was to reach out and grab the thing. Not good. It tweaked my right shoulder bad and put me in the emergency room the next morning.
Well, I got to the Orthopedic last Wednesday and he's not sure if it's a rotator cuff or upper scapula injury. Gotta go back next Wednesday for another visit after the swelling goes down a bit more. He did give me a shot of Cortisone, which seems to be working as of this moment. There is a possible MRI in my near future for this too.
Several years ago I had a ruptured bicep in the same shoulder as a result of a freak accident. I was working on a handrail on the second floor of a commercial building and my hard hat fell off my head. As it dropped I reached out to swat it back and the tendon just snapped off my shoulder. Not much pain and the Orthopedic doc said my muscles would just compensate and there was nothing he could do.
It sounds to me like your injury is similar to what happed to me.
The ruptured bicep has never hampered my ability to work (finish carpentry) or cast, but this latest incident has put me out for at least 2-3 weeks, maybe more. And the pain is much worse this time around.
Anyway, I noticed your age at 55. The bicep rupture happened to me at about that age. I'm now 60 and I believe the weakened shoulder from the first injury contributed to this current injury.
What I'm getting at is that as we age our bodies begin to degenerate, like it or not. I've always been a physical person my whole life and it's hard to admit to or adjust to the fact that it's now time to start taking things a little more on the soft side. Lesson learned the hard way.
Here's a link to a website for Orthopedic patients. It's a site to educate patients about their injury and covers a few FAQ's. Under "Item Title" look down to "Bicep Rupture". There's some good info there. Hope this helps.
Shoulder Patient Education - Orthogate - Improving orthopedic care, education and research with Internet technologies
My goal now is to train myself to cast lefty and leave the heavy work to younger bodies.
Now if I can just get those garbage cans in the back of my pickup, I gotta make a run to the dump.
Good luck with the shoulder and tight lines.