I once had a patient that injured themselves while lifting weights - bench pressing to be exact. They had lowered the barbell too quickly and heard a crunching sound. They said that there wasn't much pain but they put the barbell down and walked around for a while. Then their shoulder felt pretty good so they continued to work out. This was a foolish thing to do because that decision would cause them a lot of pain over the years.
When they first came to see me it was at least six months after the initial injury and they now had a case of frozen shoulder. They couldn't lift there arm above their head and couldn't reach around to the back of themselves either. I proceeded to treat them and gave them some exercises to do at home. After two or three weeks that problem was resolved and their shoulder felt pretty good. Then slowly over the course of a few years, pain started to return to the injured shoulder. It was not debilitating pain, but more of a constant dull pain while sitting down. They said the shoulder did not bother them when they were sleeping, but mostly when they were seated at a desk typing on a computer.
With some simple tests I could tell that the problem was now in the shoulder blade area, and there were a lot of knots and tension in the muscles around the shoulder. I also noticed that their posture was not very good, especially when they sat down at their computer. Their head was leaning forward too much causing stress on all the supporting muscles. I told them that their head weighs at least 12 pounds and when they lean forward it weighs more like 40 pounds.
So, the first order of business was to get them to improve their posture. Next I treated their painful muscles and again gave them some exercises to do at home and told them to get in the habit of stretching periodically during the day. Here are some of the excersises I assigned them.