Back pain, and specifically lower back pain, is one of the most common orthopedic complaints treated by physicians and is the second most common cause of absence for age 45-and-under employees. (The most frequent cause is the common cold.) Back pain sufferers spend more than $80 million annually in treating this orthopedic problem. Lower back pain can be caused by orthopedic sprains, strains or injury of lower back muscles and ligaments. Back pain can also be caused by orthopedic conditions including: