ABSTRACT
Pain persisting after the expected time for healing is defined as chronic pain. More than 40 million people in the United States suffer from chronic musculoskeletal pain. Chronic low back pain is a major public health problem in the United States, serving as the second most common cause of hospital admissions. Each year, approximately $25 billion is spent on direct medical costs for low back pain. When indirect costs, such as lost productivity and economic hardship, are included, the figure exceeds $100 billion annually. 1 After an initial presentation of spine-related pain, 80 to 90% of patients resolve within 6 weeks with conservative treatment. Unfortunately, a number of these patients will have relapses while others will never recover fully. This can lead to a prevalence of low back pain of 40% at 1 year after initial presentation. Chronic pain after cervical injury, or whiplash, occurs in up to 45% of patients 1 year after initial presentation.
