The purpose of the current study was to investigate the effect of microcurrent electrical stimulation (MES) applied with different polarity on the biomechanical properties of injured tendons and to correlate results with histopathological studies. Ninety six male white New Zealand rabbits were used in the study. Six rabbits were kept as normal group with intact tendons and the remaining 90 rabbits with their right Achilles tendons tenotomized, sutured and immobilized. After that rabbits were allocated into equal three groups; cathodal, anodal and control. Each group was further subdivided into three subgroups according to the study period; 3, 5 and 8 weeks. There were significant increases of all biomechanical measurements for cathodal and anodal groups than those of control group at all study periods. Furthermore there were significant increases of all biomechanical measurements in the cathodal group more than the anodal group at the 3 week period, while there was significant increase of the anodal group more than the cathodal at 5 and 8 week periods. The histopathological findings supported the biomechanical results. Tendons in cathode group showed better healing picture compared to those of anodal group at third week. While tendons in the anodal group showed better improvement at the 5 and 8 week. | Polarity effect of microcurrent electrical stimulation on tendon healing: Biomechanical and histopathological studies