As a result, it is the site of many common problems. They include sprains, strains, dislocations, separations, tendinitis, bursitis, torn rotator cuffs, frozen shoulder, fractures, and arthritis.
According to the Centers for Disease Control and Prevention, nearly 1.5 million people in the United States visited an emergency room in 2006 for shoulder problems.
National Institute of Arthritis and Musculoskeletal and Skin Disease (NIAMS)
National Institutes of Health