I am a 45-year-old woman and have been experiencing mild pain and loss of motion in my left shoulder. I have been told I might have a frozen shoulder. I am not aware of any trauma to the shoulder. For exercise I speed walk. I have well-controlled diabetes. Could you explain what frozen shoulder is?

Motion loss in the shoulder with no apparent cause is termed idiopathic frozen shoulder syndrome. The term ''idiopathic'' is used when motion loss occurs for no apparent reason. Certain medical problems may contribute to the condition, such as diabetes, cardiovascular disease and neurologic conditions. Patients with diabetes are at greater risk of developing a frozen shoulder. Often both shoulders are involved. A frozen shoulder is characterized by the joint capsule and the soft tissue that covers the joint becoming progressively thickened and scarred. This process limits motion. Most people will respond to a physical therapy program and anti-inflammatory medication. A manipulation of the shoulder joint under anesthesia to break up the scarring of the capsular tissue may be needed for those who do not respond to therapy. A small percentage of patients will continue to lose motion. In this situation, we would consider arthroscopic surgery to remove scarred tissue and restore motion. ?