Shoulders are complicated joints because of the multiple directions of motion. Pain in your shoulders will come from the tendons, the muscles or the bones. The fluid in the joint may also be lacking. It all constitutes the shoulder joint. However, the answer is very simple.
Let’s look at the cause of shoulder pain. If you follow the principles I’ve expounded on in my program you already know that inflammation and pain are an acidic state. When you stretch a muscle while it is in it’s relaxed state it gets inflamed. That’s what you are doing to your shoulder.
How are you doing that?
You do that when you sleep wrong on your shoulder. You might even wake up with pain. Your body is giving you a hint.