Earlier clinical observations of rapid changes of certain neurological dysfunctions after autotraction treatment of patients with lumbar and sacral root affections have been evaluated by objective registration methods. Isokinetic recordings of maximal voluntary strength showed that in 6 out of 8 patients, weakness of the foot dorsal flexor muscles could be more or less completely restored after one session of autotraction resulting in pain relief. In a group of patients with clinical signs of impaired sensibility, the low or abolished SEP responses to nerve stimulation on the affected side were restituted in 4 out of 5 cases during autotraction. The asymmetric leg skin temperatures in 10 patients with sciatic pain levelled off in the 6 cases obtaining pain relief by the traction. The results suggest a causal relationship between pain relief and restitution of certain neurological deficits.