When your injured shoulder stops you from doing what you want, the temptation is to push it as far as it will go. But you should learn to tell when you can ask for more and when to stop picking at it.
So you're carrying a shoulder injury. Push it or rest it? (Hint: wrong question)
Blowing your shoulder out is easy, fixing it is hard. A damaged shoulder tends to stick and because it’s such a free system, that sacrifices stability for mobility. When one part sticks it’s really hard to remobilize it. Do it wrong and all you’ll achieve is hypermobility and damage in the tissues that do still move.
Start by figuring out your range of motion. If you've never tested for shoulder range of motion before, you'll need to use your uninjured side as a model but don't expect identical effects. Most people are quite significantly lopsided, so don't think your right arm's not working because it doesn't work like your left.
Ideally take your shirt off and look in a mirror to test your shoulders. You'll be watching the head of your shoulder to check that you're not "inventing" range of motion by borrowing it from scapular tilt. Press out overhead and slightly in front of your head. Watch to see that your elbows are facing the same direction. Try pressing out to the sides and then doing internal and external rotations on both arms with your elbow at your ribs, and finally with your elbow at shoulder height.
If there's no pain most of the time but you get pain in a certain axis of motion (for instance, if you can do everything except externally rotate) then you should see a professional about what could be nerve or serious tissue damage.
If you have range of motion stoppages or sudden slips and glitches in movement you probably have a stability problem arising from motor patterning. If toward the end of your range of motion, you're halted by pain, or by a feeling that you've reached the natural end of something, not dysfunction, read on and we'll talk about how to deal with it.
The End Point: Where Your Shoulder Stops
Every joint has an end point, where it stops moving. For instance, when you extend your arm, it won't extend past a certain point because the elbow stops it. That's a bone end point. And when you bend your arm it won't bend any further because your upper and lower arms are pressing into each other. Then you have a "leathery" feel, which is the feeling of ligaments or the joint capsule not allowing any further movement. It's likened to the feel of stretching a piece of leather and it's the normal way shoulder motion stops. If yours stops in an acceptable range of motion, without pain or dysfunction, and the end point feels like this, you might have just found your natural shoulder range of motion.