One of the most common questions I’m asked is “Is it frozen shoulder?”. It is often a difficult question to answer because Frozen Shoulder is a lay term, and so can sometimes mean different things to different people. Here we will discuss the main causes of shoulder pain.
In its true meaning, Frozen Shoulder is synonymous with Adhesive Capsulitis. This is a particularly painful shoulder condition where the synovium (which produces the joint fluid) becomes inflamed and the joint capsule (which is the fibrous bag that contains and the joint fluid) contracts. These processes result in pain and joint stiffness. The whole process takes about 18months to resolve and is unfortunately fairly resistant to manual therapy. You would know if you had it because the joint would become extremely stiff, and even with you elbow next to your side rotating your arm outwards would be difficult.
So, now you may be relieved that it is not a true frozen shoulder, what other more common causes of shoulder pain are there?
Rotator cuff problems are very common. The rotator cuff is a group of four muscles that act together to keep the ball of the shoulder joint in the centre of its very shallow socket. The rotator cuff muscle Supraspinatus is most commonly affected. It is often over stretched when a person lifts a weight across their midline, or pinched against the overlying cap of the shoulder blade, and also has a poor blood supply to the tendon. These three factors combined mean that the Supraspinatus muscle often becomes injured and then does not heal fully. The main way of testing whether you have a problem in your supraspinatus muscle is to test it against resistance. Holding a small weight, bring your arm out straight ahead of you so that it is just below the horizontal, and then rotate your arms so that your thumb points down toward the floor. If this is painful you may have some wear and tear, and if it is very weak then you may have a tear in the tendon.
Impingement Syndrome. This is a really common biomechanical problem in the older generation but with early management can be easily resolved. Impingement really means the humerus (arm bone) and acromium (boney cap of the shoulder blade) bump together which can cause pain. The way to test if you have this is to hold your arm out at 90o to the side of you with your elbow bent and your hand pointing down to the floor. Rotate your arm so that the hand points up to the ceiling. This movement should be painfree and fluid. If it’s not then you might have an impingement syndrome. The cause is often a mispositioning of the shoulder blade to far forward on the ribcage. In this case treatment addresses the mechanics behind this and the condition usually resolves very well.
Osteoarthritis. Shoulder arthritis is not as common as hip or knee arthritis but is still significant cause of shoulder pain. Wear and tear of the shoulders cartilage is common in those who have injured the joint previously perhaps through a dislocation, or in those who have had a manual occupation. The stiffness tends to be less than obvious than in adhesive capsulitis, and doesn’t have such a sharp stop at the end of the movement.
Other less common causes of shoulder pain include acromioclavicular joint pain, bursitis, and instability.