5. Strain.
Another common cause of shoulder blade pain is a strain on any of the muscles that are situated in or around the area. There are a number of reasons why the muscles that lie within or around the shoulder blade can become strained. For example, if you have fallen and used your arm to brace yourself, you may have strained the muscles of the shoulder blade.
Other factors that can lead to strain include arthritis and tendonitis. There are several symptoms that are associated with a shoulder strain, including swelling and bruising of the affected area, redness at the site where the injury occurred, throbbing, aching, and weakness in the arm.
If the strain is severe, you may have extreme difficulty moving the shoulder at all. With rest, the application of hot and cold compresses, and anti-inflammatory medications, the condition should subside. Physical therapy may be recommended in severe cases.