Why the syndrome occurs is a bit of a mystery. It is more common in people between the ages of forty and sixty years and is often associated with a bursitis. It can occur in athletes following trauma if the shoulder is immobilized for an excessive period of time, but this seldom happens. Many people acquire the syndrome without any specific at all. It may develop in people following a virus and can even affect both shoulders of an individual consecutively over a period of years.

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