The immediate effects of heat and TENS on pressure pain threshold and pain intensity in patients with Stage I shoulder impingement syndrome

Aim: Our study was planned to compare the immediate effects of heat, transcutaneous electrical nerve stimulation (TENS) and heat plus TENS applications on the pain related to stage I shoulder impingement syndrome. Methods: 92 patients who had shoulder impingement syndrome were separated randomly in three groups. The heat was applied to 31 patients in the first group for 20 min, TENS (100 Hz 0.1 ms pulse duration, symmetric biphasic wave form, tolerable intensity) was used for 30 patients in the second group for 20 min and heat plus TENS was applied to the 31 patients in the third group for 40 min. Before and immediately after the applications, pressure pain threshold (PPT) was measured by a dolorimeter in the painful points on the anterobrachial area. Measurements were repeated three times and the mean value was recorded. The severity of subjective pain was recorded using a visual analogue scale (VAS) before and after the applications.One-way ANOVA was used to compare differences of PPT, VAS, and physical characteristics among groups before and after applications. A paired sample t-test was used to compare PPT and VAS values before and after applications. Results: It was observed that while PPT values increased immediately after applications in all groups, VAS scores decreased (p < 0.05). No statistically significant difference was found in PPT values and VAS scores before and immediately after the applications among the groups (p > 0.05).