Ultrasound images have been widely adopted to investigate the human muscle fascicles as a non-invasive method that imparts no radiation. However

manual measurement of fascicle orientation from ultrasound images can be subjective and time-consuming in clinical enviroments. In this paper

a new approach is proposed to detect and track the fascicle orientation automatically by using the texture feature of the fascicle region. The ultrasound images are projected using a normalized Radon transform. For each Radon orientation

the variability of the results of the normalized Radon transform is statistically measured by Segmented-Variance. Compared to traditional methods that directly detect the line feature of the fascicles can be directly detected in this way and the proposed method makes full use of the texture feature of the parallel distribution of the fascicles. The result shows that the robustness of the orientation detection has been enhanced. Four ultrasound sequences are tracked consecutively to evaluate this method. The correlation coefficient of the detection results between the proposed method and manual method is 0.90±0.01

and the average of the absolute difference between these two methods is 0.41°±0.31°. We believed that the proposed method has a great potential in ultrasonic image analyzing and the biological mechanics field.