Negative disc exploration: positive canal signs.

It is common practice for those concerned with the treatment of patients with the many patterns of pain arising from the vertebral column to assess ranges of intervertebral joint movement and to associate with this assessment that of the behaviour of pain during the test movements. This clinical paper deals with the examination of movement of the pain sensitive structures in the vertebral canal (the dura mater and nerve root sleeves) and the clinical implications of restriction in range together with reproduction of the patient's pain. The possible clinical findings are considered in relation to low back pain, tethering of pain sensitive vertebral canal structures in pre and post laminectomy patients, the 'juvenile disc' patients and patients with headaches.