The problem of low back pain is enormous in all industrialized societies. Attempts to decrease its impact by different educational, ergonomic, or treatment methods have generally failed. The deleterious effects of long-term absence from activity and work are well known. New information is available regarding the healing time and properties of possibly diseased tissues and the actual loads on the lower back in various positions of activity and work; data are also available regarding the perception of pain, both acute and chronic, and how it can be affected by muscle activity. This new information may well serve as a basis for a new type of treatment for back pain--early, gradual, biomechanically controlled return to activity and work for the 80% of patients with back pain in whom no objective cause for the pain can be found after a thorough examination.