I have had a lot of trouble with my right shoulder for many years. For many months it has felt like a knife is lodged behind my shoulder blade. It is always there. I am used to it. The pain briefly departed after a cortisone injection into the bursa under my shoulder blade, which confirmed a diagnosis of snapping scapula.
The next step from there is surgery.
I have previously had a subacromial decompression on my right shoulder, and I can tell you that I need the same done on my left shoulder. All movement is painful and I can hear everything cracking and grinding as I force my arms to move in big circles every day. Move it or lose it. Pain does not stop me moving joints. In fact, pain makes me move them more. I have seen what happens when I stop moving…those joints seize. And to get them moving again is more pain than if I never let them seize in the first place.