A painful inflammatory process leads to a mechanical block in active and passive range of motion (ROM) of the shoulder. Adhesive capsulitis of the shoulder is characterized by functional loss of passive and active shoulder motion. This inflammatory process results in fibroblastic proliferation and extensive scar tissue formation. Fibroblastic proliferation, a late phase of the inflammatory process involved in tissue repair, leads to thickening, fibrosis, and adhesion of the capsule to itself and the humerus.