Shoulder pain

Pain under the acromion often occurs on the outer side of the joint. It gets worse when you lift your arm sideways (see illustration). Sometimes the pain gets worse if you lie on the affected shoulder at night. It might then wake you up.

Various things can make the space under the acromion (the subacromial space) narrower. These include bony growths, “wear and tear” and calcium deposits in the supraspinatus tendon (see illustration). Other causes include an inflamed fluid-filled sac or a hooked acromion, where the tip of the shoulder blade curves down more than usual. Sometimes ligaments and tendons in the joint capsule become shorter due to weak muscles or putting abnormal strain on the muscles.

All of these things can cause parts of the shoulder tendons (“rotator cuff tendons”) and the fluid-filled sac (“bursa”) to become pinched between the acromion and the head of the upper arm bone when you lift your arm.

Because so many different things can cause pain under the acromion, a variety of terms are used when diagnosing the problem. These include “shoulder impingement,” “rotator cuff syndrome” and “calcific tendinitis of the shoulder.”

Research has shown that there’s no clear link between the symptoms people have and things that can be seen on ultrasound, x-ray or MRI images. Sometimes people don’t have shoulder pain even though these images show that there are calcium deposits, tears and “wear and tear” in the rotator cuff (a group of muscles and tendons that surround the shoulder joint) or the shoulder labrum (a ring of cartilage around the shoulder socket). Because of this, many experts now prefer to call it “subacromial pain” (pain under the acromion) rather than “shoulder impingement.” It’s not clear what role soft tissue becoming pinched (impingement) actually plays in the development of shoulder pain.

People who frequently have to work on something above their head are at greater risk of developing subacromial pain. Common examples include painters, electricians, warehouse workers and shelf stockers.

Certain sports involve moving your arms above your head a lot as well – for instance, tennis, basketball or other ball games. Swimmers who do the front crawl or butterfly stroke also usually swing their arms up over their heads. Intensive training can then lead to shoulder pain.

Weak shoulder muscles, ligaments and tendons can also result in shoulder pain. The shoulder is a very movable joint that is mainly kept stable by the muscles. If the shoulder muscles are weak, the head of the upper arm bone (humerus bone) may “fall” out of the socket and push against the surrounding soft tissue.

Shoulder pain is one of the most common orthopedic problems, along with back and neck pain. In up to 70% of those affected, the pain arises under the acromion (“subacromial pain”).

The course of shoulder pain can vary from person to person. In about half of those affected, the pain goes away within six months. But in some people it can continue for many years.

To find out what's causing the symptoms, the doctor will ask questions like

• when the pain occurs and how it feels,
• whether there was an injury or accident, and
• whether it could have been caused by things like overhead work or certain types of sports.

The physical examination that follows includes several tests that involve lifting and lowering your arms sideways, and moving your elbows in various directions, inwards or outwards. The doctor will also feel your shoulder. This is usually enough to diagnose subacromial pain. During the physical examination the doctor can also rule out other possible causes of the pain, such as radiating neck pain or frozen shoulder (adhesive capsulitis).

Sometimes people have examinations with imaging techniques, too: For instance, a torn rotator cuff can be seen in ultrasound images, and the bones and calcium deposits can be seen in x-ray images. A magnetic resonance imaging (MRI) scan may be considered if the cause has still not been found.

Because there’s no clear link between people’s symptoms and the changes or “wear and tear” seen in the images, these imaging techniques aren't always needed. They may be a good idea if the symptoms don’t improve despite treatment, if surgery is being considered, or if there’s reason to believe that something else is causing the pain. For instance, x-ray images can help to find out whether the person has osteoarthritis of the shoulder joint.

People who have acute shoulder pain are advised to

• go easy on their shoulder, taking special care to avoid work or sports that involve lifting the affected arm up over their head,
• cool the shoulder,
• relieve the pain with anti-inflammatory (inflammation-reducing) painkillers such as ibuprofen, if necessary. But these painkillers shouldn't be taken for longer than 1 to 2 weeks. If the pain is very bad, steroid injections can be used too.

Going easy on your shoulder doesn't mean you should stop moving your arm completely – on the contrary: By doing certain physical therapy exercises, the shoulder can gradually become more movable and stronger again. Research has found that continuing the exercises you learn in physical therapy at home and doing them correctly is just as effective as doing the exercises under the supervision of a therapist.

Shoulder surgery isn’t likely to help much in people who have subacromial pain. Good-quality studies have shown that surgery to widen the space under the acromion usually doesn't help any better than treatment where people only think they have had this surgery. Surgery is always associated with risks and can lead to other shoulder problems, so it’s important to carefully consider the pros and cons before deciding whether or not to have it done.

When people are ill or need medical advice, they usually go to see their family doctor first. Information about health care in Germany can help you to navigate the German health care system and find a suitable doctor. You can use this list of questions to prepare for your appointment.