Rotator cuff refers to a group of tendons and muscles around the shoulder. Overuse of the shoulder (due to strenuous activities e.g., playing tennis, volleyball or swimming) can loosen the rotator cuff, causing this problem.

Frozen shoulder, medically referred to as adhesive capsulitis, is a disorder in which the shoulder capsule, the connective tissue surrounding the glenohumeral joint of the shoulder, becomes inflamed and stiff, greatly restricting motion and causing chronic pain. In frozen shoulder, there is a lack of synovial fluid, which normally helps the shoulder joint, a ball and socket joint, move by lubricating the gap between the humerus (upper arm bone) and the socket in the scapula (shoulder blade). The shoulder capsule thickens, swells, and tightens due to bands of scar tissue (adhesions) that have formed inside the capsule. As a result, there is less room in the joint for the humerus, making movement of the shoulder stiff and painful. Frozen Shoulder is commonly seen in diabetics, Hypothyroid patients, Post stroke, Post injury to shoulder and following lung and heart disease. Adhesive capsulitis is a painful and disabling condition that often causes great frustration for patients due to slow recovery. Movement of the shoulder is severely restricted. Pain is usually constant, worse at night, and when the weather is colder. In addition to difficulty with everyday tasks (like changing clothes, combing etc), people who suffer from adhesive capsulitis usually experience problems sleeping for extended periods due to pain that is worse at night and restricted movement/positions.