The natural history of idiopathic low back pain. A three-year follow-up study of spinal motion, pain and functional capacity.

During a three-year follow-up study of 31 chronic idiopathic low back pain patients significant spontaneous improvements of pain and disability scores were found, while range of motion of the lumbar spine decreased. It is argued that increasing stiffness of the low back may be the clinical manifestation of the process of stabilization, that takes place in previously painful instable motion segments. The present findings have also implications for the interpretation of changes of spinal motion. Restriction of range of motion seems to be a normal long-term development in low back pain patients and is accompanied by a diminution of pain and disability.