Frozen shoulder is a painful condition in which your shoulder movement becomes limited. Another name for frozen shoulder is adhesive capsulitis.

Frozen shoulder occurs when the strong connective tissue surrounding your shoulder joint(called the shoulder joint capsule) becomes thick, stiff and inflamed. The joint capsule contains the ligaments that attach the top of your upper arm bone (humeral head) to your shoulder socket (glenoid), firmly holding the joint in place. This is more commonly known as a ball-and-socket joint.

The condition is called “frozen” shoulder because the more pain you feel, the less likely you’ll use your shoulder. Lack of use causes your shoulder capsule to thicken and become tight, making your shoulder even more difficult to move — it’s “frozen” in its position.