150 Dutch patients 18 years of age or older who presented to their primary care physicians with shoulder pain, defined as pain that occurs at rest or during movement of the upper arm in the area between the neck and the elbow and that is accompanied by neck symptoms. Patients who had signs of compression of the nerves in the neck or whose shoulder pain was due to severe trauma, fracture, rupture, dislocation, specific joint disease such as rheumatoid arthritis, or disease of the chest or abdomen were not eligible for the study.