I had shoulder problems in the joint. I resolved those with a combination of placing my finger on the joint and pressing down onto the top of the bone and rotating it, and rotator exercises with a 15 lb dumbbell.
There were two rotator exercises I did:
Standing, with my elbows bent and my hands pointing straight up, holding 15 lb dumbbells, lower my hands to the front, keeping the elbows bent at 90 degrees, and rotating only the shoulder joint, then raise to the starting point. That is 1 rep. I did 3 sets of 15 reps of these.
Lying on my side on a bench, I extended my top arm straight to the front of my chest (with my arm straight or slightly bent at the elbow), holding a 15 lb dumbbell. Then I lifted the arm across my chest until it was pointing straight toward the ceiling (kind of like a reverse flye) then I lowered the arm to the point of beginning. That is one rep. I did 3 sets of 15 reps of these.
It didn't take long, maybe 3 months of the rotator exercises to clear up my shoulder problems. Now if they flare up I do a few weeks of the exercises and they are gtg again.