Subacromial Pain Syndrome

Subacromial Pain Syndrome

The term subacromial pain is often used synonymously with the term’s rotator cuff disease, rotator cuff tendinosis, and shoulder impingement syndrome.


As calcifying tendinopathy of the shoulder can also present with shoulder pain, the subacromial pain syndrome can also include calcification of the tendons. Sometimes the term rotator cuff tendonitis is confused with the term shoulder bursitis, but both terms refer to an inflammation of a particular area within the shoulder joint (i.e., the subacromial space) that is causing a common set of symptoms and is named shoulder impingement syndrome (SIS). The term SIS is descriptive and refers to compression of the tendon and bursa of the rotator cuff in the subacromial space. In most acute cases SIS is a combination of inflammation of the rotator cuff tendons (tendonitis) and inflammation of the bursa that surrounds these tendons (bursitis). In many cases of SIS the subacromial space is reduced because of the different shape of the bones compared to healthy control people.

The condition is often caused by an initial injury, starting the inflammatory process which may cause thickening of the tendons or bursa. This thickening then takes up more space and compressing these structures even more, resulting in more inflammation. The problem therefore can be self-exacerbating, resulting in a vicious circle of inflammation, thickening of the tendons and bursa, compression of these structures, more inflammation, and so on.

Subacromial Pain Syndrome Patient Treated with Shock Wave


Diagnosis is based on the clinical features of the disease. Diagnostic imaging such as ultrasound should be considered to rule out other causes of shoulder pain (including calcifying tendinopathy of the shoulder) or to establish the diagnosis of SIS when in doubt.

‘Shoulder impingement syndrome (SIS) is the most common form of shoulder pain, and repetitive activity at or above the shoulder during work or sports (including swimming, throwing, tennis, weightlifting, golf, volleyball, and gymnastics) represents the main risk factor for SIS. Increasing age predisposes to SIS.’

Three different stages of SIS are distinguished:

• Stage 1 (acute inflammation, oedema, and haemorrhage in the rotator cuff): conservative treatment including rest, icing, physiotherapy, and nonsteroidal anti-inflammatory drugs.

• Stage 2 (continuum of Stage 1, with the rotator cuff tendon progressing to fibrosis and tendonitis): conservative treatment, shock wave therapy (SWT), or surgery when conservative treatment and SWT fail.

• Stage 3 (mechanical disruption of the rotator cuff tendon and/or changes in the coracoacromial arch with osteophytosis along the anterior acromion): surgery.

Shock wave therapy can be a very effective element of shoulder impingement syndrome treatment.

Subacromial Pain Syndrome