You often don’t know what you don’t know.
And sometimes you don’t know what you thought you knew.
I just realized the upper arm bone rests in a socket that’s on the shoulder blade. Maybe I never needed to think about it before, so I vaguely thought the socket for the upper arm bone was connected to the rib cage with the shoulder blade floated behind it.
Why would the structure of the shoulder be on your radar if you’re not in the medical profession? Until your get a frozen shoulder. I was diagnosed with a frozen shoulder and started googling it to see what the different treatment options are.
It took a while before I understood how our shoulders work. Not because it’s that complicated, though it’s more complicated than the model of it that was in my mind. I guess I was a little slow on the uptake because I assumed I knew how the joint worked, plus at first most of the shoulder joints presented showed the joint with muscles and other soft tissues in place.
Finally the scales lifted from my eyes and I understood that the socket for the arm is part of the shoulder blade itself.
I’m sure I’ve seen pictures like the one here before, but it never overwrote the blindspot I had of how I imagined the joint.