title: A study of the natural history of back pain. Part I: development of a reliable and sensitive measure of disability in low-back pain.
mesh_terms: D000203:Activities of Daily Living; D000293:Adolescent; D000328:Adult; D001416:Back Pain / Q000175:diagnosis*; D004185:Disability Evaluation; D006801:Humans; D008875:Middle Aged; D009068:Movement