Frozen shoulders can come on after a period of disuse of the arm.
A frozen shoulder can also come on for no apparent reason at all. Frozen shoulders can be particularly severe in individuals with diabetes. Scapulothoracic range of motion can be limited by such factors as sternoclavicular arthritis, acromioclavicular arthritis, contracture, rib or scapular fracture, post-traumatic scarring, tumor, dislocation, or other factors disrupting the scapulothoracic motion interface. If you would like, you can learn more about humeroscapular motion or scapulothoracic motion . In post-traumatic stiff shoulders the relationship of loss of motion to previous surgery or injury becomes evident from the history.