The mechanism of what triggers a frozen shoulder is not clearly understood. What we do know, however, are the groups who face the greatest risk of incurring this condition. Frozen shoulder is more common in those over forty, women, and much more prevalent in diabetics and those who have suffered from a stroke, thyroid disease, recent surgery, or Parkinson’s disease. 

There are two classifications:

1. Primary Frozen Shoulder. This occurs without an identifiable cause.

2. Secondary Frozen Shoulder. This occurs as a result of injury, surgery, or illness.

Risk Factors

Frozen shoulder affects 2% of Americans. For reasons not well understood, it occurs more often in the non-dominant shoulder, is more prevalent in women, and occurs most often in people between the ages of 40 and 60. 

Other known risk factors include the following:

• Diabetes. Frozen shoulder affects 10% to 20% of diabetics, for unknown reasons

• Immobilization of shoulder

• Hyperparathyroidism

• Inflammation/autoimmune reaction

• Parkinson's disease

Treatment Options for Frozen Shoulder

Hierarchy of Treatment

The most fundamental component of treating a frozen shoulder is moved. Immobility worsens this condition. This is why shoulders are rarely immobilized as part of a treatment plan for injury and motion is introduced early. The most common treatments for frozen shoulders are mobility exercises and anti-inflammatory drugs. Manipulation of the shoulder is also indicated. In resistant cases, injected steroids are utilized. In rare cases, manipulation under anaesthesia or surgery may be indicated. Of note, steroid injections have a similar benefit to manipulation–under-anesthesia (MUA) without the risks associated with anaesthesia.


The primary treatment for frozen shoulder is stretching. Other treatments include the use of non-steroidal anti-inflammatory drugs (NSAIDs) like ibuprofen or aspirin, corticosteroid injections into the affected shoulder, manipulation, mobilization, friction massage, and therapeutic modalities. In persistent cases, manipulation under anaesthesia, or surgery are required to restore shoulder motion.