Disorders of the shoulder are extremely common, with reports of prevalence ranging from 30% of people experiencing shoulder pain at some stage of their lives and up to 50% of the population experiencing at least one episode of shoulder pain annually. In addition to the high incidence, shoulder dysfunction is often persistent and recurrent, with 54% of sufferers reporting ongoing symptoms after 3 years.

Patients often express that their pain is localized to one of four anatomic regions. The anterior (front) arm, the posterior (back) shoulder , the lateral arm (side), or the superior (top) shoulder. Anterior shoulder pain is commonly associated with biceps tendon pathology, frozen shoulder or shoulder instability. Posterior shoulder pain is often referred from the neck or local muscles of the neck and upper back. Lateral arm pain is commonly associated with rotator cuff pathology or subacromial impingement. Superior shoulder pain occurs with acromioclavicular joint problems, or referals from the neck.

Patients will often describe pain or stiffness when raising the arm to the side or reaching behind the back. Pain is often aggravated at night time.