Classification and Epidemiology: Classification of Stiff Shoulder -- Epidemiology. Etiology: Idiopathic -- Post-Traumatic -- Post Cuff Repair -- Post Instability Repair -- Other Post Surgical -- Other Causes (Cuff Disease, Impingement, Osteoarthritis, heterotopic ossification, etc). Anatomy and Biomechanics: Anatomy Related to the Range of Motion -- Biomechanics Related to the Range of Motion -- Rotator Interval and Stiffness. Examinations: Pathophysiology: Histology and Laboratory Tests -- Clinical Symptoms -- Physical Examinations -- Imaging. Conservative Treatment: Natural Course -- Conservative Treatment. Surgical Treatment: MUA -- Arthroscopic Release -- Postop. Rehabilitation Program -- Reported Outcomes and Results: What should we and the patient expect?.