bowling, swimming, tennis, baseball, and kayaking are often implicated. Progression to a hooked acromion could be an adaptation to an already damaged, poorly balanced rotator cuff with resultant stress on the coracoacromial arch. Other anatomical factors include an os acromiale and acromial spurs. Environmental factors include age, shoulder overuse, smoking, and medical conditions that affect circulation or impair the inflammatory and healing response, such as diabetes mellitus. Intrinsic factors Intrinsic factors refer to injury mechanisms that occur within the rotator cuff itself. The principal is a degenerative-microtrauma model, which supposes that age-related tendon damage compounded by chronic microtrauma results in partial tendon tears that then develop into full rotator cuff tears. As a result of repetitive microtrauma in the setting of a degenerative rotator cuff tendon, inflammatory mediators alter the local environment, and oxidative stress induces tenocyte apoptosis causing further rotator cuff tendon degeneration. A neural theory also exists that suggests neural overstimulation leads to the recruitment of inflammatory cells and may also contribute to tendon degeneration. Surgical considerations Depending upon the diagnosis, several treatment alternatives are available. They include revision repair, non-anatomic repair, tendon transfer and arthroplasty. When possible, surgeons make tension-free repairs in which they use grafted tissues rather than stitching to reconnect tendon segments. This can result in a complete repair. Other options are a partial repair, and reconstruction involving a bridge of biologic or synthetic substances. Partial repairs typically are performed on retracted cuff tears. Tendon transfers are prescribed for young, active cuff-tear individual who experience weakness and decreased range of motion, but little pain. The technique is not considered appropriate for older people, or those with pre-operative stiffness or nerve injuries. People diagnosed with glenohumeral arthritis and rotator cuff anthropathy have the alternative of total shoulder arthroplasty, if the cuff is largely intact or repairable. If the cuff is incompetent then a reverse shoulder arthroplasty is available and, although not as robust a prosthesis, does not require an intact cuff to maintain a stable joint. Diagnosis Diagnosis is based upon physical assessment and history, including description of previous activities and acute or chronic symptoms. A systematic, physical examination of the shoulder comprises inspection, palpation, range of motion, provocative tests to reproduce the symptoms, neurological examination, and strength testing. The shoulder should also be examined for tenderness and deformity. Since pain arising from the neck is frequently 'referred' to the shoulder, the examination should include an