The most well-known ailment affecting the neck muscles is neck stiffness, caused by sharp changes in temperature, chilling of the muscles by air conditioning or drafts, and consequent painful muscle contractions. A stiff neck is typically characterized by soreness and difficulty in moving the neck especially when trying to turn the head to the side. A stiff neck may also be accompanied by a headache, neck pain, shoulder pain and/or arm pain. Reduced cervical range of motion (ROM) is a common finding in people with neck pain. Musculoskeletal disorders continue to represent a major source of pain and discomfort as well as a significant source of workday loss and workers' compensation costs.