Abstract: On April 16, 2003, Employee #1, an aircraft electrical mechanic, was working at a Boeing Company aircraft manufacturing facility. He was riveting over his head in Building # 54, Department 17C center fuselage, when he suffered a neck and thoracic sprain. He complained of chronic neck pain radiating down his left arm and was hospitalized for surgery. After interviewing Employee #1, and reviewing documents supplied by the employer, it was determined that the injury was primarily caused by a preexisting condition. The employer had a good ergonomics program in place, and a voluntary stretching program was available during the day, along with needed breaks.