Adhesive capsulitis, commonly called frozen shoulder, involves pain, loss of motion, inflammation, and adhesions or scarring of the capsule that surrounds the shoulder joint. Frozen shoulder may occur following an injury or immobilization of the shoulder joint, such as after surgery. The bone, ligaments and tendons that make up your shoulder joint are encased in a capsule of connective tissue. Frozen shoulder occurs when this capsule becomes inflamed, thickens and tightens around the shoulder joint, restricting its movement and causing pain. This pain often leads to avoiding movement of the arm. This lack of movement leads to stiffness, and then to even less motion. Over time, it will become difficult or painful to perform movements like reaching over head or behind your back.