Shoulder pain is a common musculoskeletal disorder and has a substantial negative effect on quality of life. Its monthly prevalence in the general population is reported to be between 18% and 31%, whereas lifetime prevalence ranges between 6.7% and 66.7%. Shoulder pain is the third most frequent musculoskeletal reason to present to primary care and accounts for up to 10% of all referrals to physical therapists. Although the natural history of shoulder pain varies and is often self-limiting,up to half of persons who present for care, particularly the elderly, might continue to have pain and/or functional disturbance for up to 2 years after presentation.