The purpose of this study was to investigate the biomechanical properties of the lateral ankle ligaments and to correlate these properties with the distribution of mechanoreceptors in the ligaments reported previously. Biomechanical tensile tests were performed by using a video dimension analyzer to monitor the distortion of the lateral ligament at the pole and center in the animals. The mean upward slope of the load-elongation curves of the pole group was 38.1+/-14.2, and that of the center group was 79.1+/-6.5. The pole of the ligaments tended to be elongated more than the center. These biomechanical results suggest that mechanoreceptors in the pole of the ligaments, compared with those in the center, may receive more mechanical stress and be effective in monitoring of tension applied to the ligament.