Vertical oscillatory pressure is a technique used for the treatment of back pain, This monogragh reports the observed effects of VOP on pain and Cortical Evoked Potentials.10 neck pain (NP),10 Low Back Pain (LBP) patients and 10 controls (age range 30-64years) received VOP while recording their electroencephalogram.Naloxone was dministered and VOP re-applied.Pain was assessed using a 10-point scale before,during and after.Controls were not treated but EEG and pain scores were recorded. CEPs appeared in the hemisphere contralateral to the painful side of the spine,10-15milliseconds after VOP. CEPs were significantly> than normal potentials in amplitude (P<0.01) and frequency (P<0.05) appearing as polyspikes waxing and waning alongside +ve deflections. CEPs increased significantly during Digital Pressure (LBP, P < 0.001; NP,P<0.001) and oscillation (LBP, P <0.01; NP, P <0.001) after Na. Pain decreased post VOP in those with backpain. VOP increased CPs amplitude and frequency while releaving pain. Increases in pain severity after Na suggest that increased CPs amplitude and frequency stimulate the opioid systems to enhance VOP analgesic potency.