Objective
The purpose of this study was to evaluate the most effective stimulating electrode in TENS for pain relief, and to apply to the treatment of patients with neck and shoulder problems.

Method
The objects were 30 patients with neck and shoulder problems. In 10 of them, insulated needle electrodes were inserted into a trigger point and electrical stimulation given through the electrodes. In 10 of them, non-insulated needle electrodes were applied as the same method. The others were treated with lidocaine injection into a trigger point and electrical stimulation given through the surface electrode. The effects of pain relief were assessed by visual analogue scale (VAS), pain rating score (PRS), and pain algometer.

Result: In the group with insulated needle electrode, the average score was reduced 48.33⁑24.84% in VAS score and 52.00⁑17.55% in PRS, the pressure of pain algometer was increased 34.97⁑15.33%. In non-insulated needle electrode group, reduced 43.16⁑34.62% in VAS score and 43.73⁑34.85% in PRS, the pressure was increased 22.28⁑30.62%. The score reduction of surface electrode group was 20.61⁑15.73% in VAS score and 18.22⁑16.27% in PRS, the pressure-pain threshold increased as 9.05⁑12.81%.

Conclusion
The results suggest that insulated and non-insulated needle electrodes were more effective stimulating electrode in TENS for pain relief than surface electrode.