Shoulder Impingement Syndrome

Acromial arch

Impingement syndrome is sometimes called swimmer’s shoulder or thrower’s shoulder and is caused by the tendons of the rotator cuff becoming impinged as they pass through the shoulder joint.

It may follow a partial tear of a rotator cuff tendon, or come on gradually through overuse.

Symptoms

Symptoms include pain which comes on gradually over a period of time. There will be pain at the front and side of the shoulder joint, especially during overhead movements such as in throwing, racket sports and swimming.

There may be pain in the shoulder when the arm is held out to the side turned outwards (abduction and external rotation). Another give away sign of impingement is pain in an arc from about 70 degrees to 130 degrees when lifting the arm out sidways and up above the shoulder.

Read more on symptoms and diagnosis.

What is impingement syndrome?

Rotator cuff muscles

Shoulder impingement syndrome, which is sometimes called swimmer’s shoulder or thrower’s shoulder, is caused by the tendons of the rotator cuff muscles becoming impinged as they pass through a narrow bony space called the subacromial space. The subacromial space is so called because it is under the arch of the acromion. With repetitive pinching, the tendons become irritated and inflamed.

This can lead to thickening of the tendon which may cause further problems because there is very little free space, so as the tendons become larger, they are impinged further by the structures of the shoulder joint and the muscles themselves.

Impingement Syndrome in itself is not a diagnosis, it is a clinical sign. There are at least nine different diagnoses which can cause impingement syndrome which include bone spurs, rotator cuff injury, labral injury, shoulder instability, biceps tendinopathy and scapula dysfunction. If left untreated, shoulder impingement can develop into a rotator cuff tear.

The supraspinatus muscle is probably the most commonly involved in impingement syndrome of the shoulder.

Shoulder impingement is classified as internal or external depending on the causes with external impingement being divided into primary which is caused by a bony spur or some direct cause and secondary impingement which occurs as the result of poor stabilization of the shoulder joint.

Read more on causes of shoulder impingement.

Treatment

Treatment for shoulder impingement is based around reducing pain and inflammation, increasing mobility and strength whilst identifying and correcting the possible causes to ensure it does not reccur.

Apply the PRICE principles of protection, rest, ice, compression and elevation. Rest the shoulder from any painful activities or movements. Pain indicates increasing inflammation and delaying the healing process. Apply ice or a cold therapy and compression wrap to the painful area for 10-15 minutes per hour initially reducing to 3 or 4 times a day as symptoms reduce. Remember to use an ice bag or a towel wrapped around the ice to protect against ice burn.

A doctor may prescribe anti-inflammatory medication such as Ibuprofen to reduce pain and inflammation. A professional therapist may use electrotherapy such as ultrasound to help reduce pain and inflammation as well as advise on a suitable rehabilitation and exercise program.

Specific tests to confirm the diagnosis including X-Rays to what is causing the impingement. They may discuss the option of directly injected steroids into the subacromial space to reduce inflammation and reduce inflammation in the local area although this is not usually an early option. It is usually recommended after a period of at least 6-12 months.

Read more on treatment and rehabilitation.