Characteristics Of Ultrasonic Image Entropy In Muscle Fatigue

Muscle fatigue is a phenomenon that the maximum voluntary contractions of muscle strength reduced with the muscular movement, and it usually occurs in our daily life, especially when the muscle fatigue is mishandled in sports, it would affect the follow-up training of an athlete. Muscle tissue also has the movement limit, excessive fatigue is the cause of damage tissue. And with the competitive level improved continuously in sports, it is hard to avoid to make the pressure to coaches and athletes, and the accurate assessment of muscle fatigue would provide method to avoid injury events in the physical training process.The changes of muscle movements can be detected and monitored in real-time with the ultrasound images. In order to assess the muscle fatigue precisely, we use entropy features in the ultrasound images to characterize the spatial texture of grayscale distribution of the ultrasonic image, and we gain the muscle fatigue characteristics by studying the evolution law of entropy in ultrasound images during the process of muscle fatigue.The mainly works can be included as follows:(1) As ultrasonic image entropy can characterize the properties of the image attributes, and reflect the gray level distribution information in the current pixel location and the comprehensive characteristics of gray distribution in neighborhood. Combiningit with the ultrasound image texture in the B-system, we analysis the correlation between fatigue properties of muscle tissue and ultrasonic image entropy in theory.(2) According to the results of the theoretical analysis, we designed a set of ultrasonic image entropy detection system for muscle tissue, which can obtain the variation characteristics of muscle ultrasound image entropy in training.(3) We studied the ultrasound image entropy feature of biceps brachii during fatigue process and muscle fatigue sustained time through the detection system. By the study on muscle fatigue characteristics of10subjects’biceps brachii at different moments of20%MVC,30%MVC,40%MVC,50%MVC correspondingly, we would gain the correlation between muscle fatigue and ultrasound image entropy. Theoretical and experimental results showed that there is a certain correlation between fatigue properties and the ultrasonic image entropy of the muscle tissue. We got the muscle fatigue characteristics of the same subject at different torques, and the characteristics of different subjects at the same moment during muscle fatigue. As muscle strength and muscle cross-sectional area is positive correlated, cross-section area of muscle fiber were also associated with muscle strength positively, the increased cross-sectional area will bring more neat arrangement of muscle fibres, it is the reduce of image entropy from the angle of image entropy. As we know that there are individual differences in muscle energy, but the energy consumption rate of the same subject positively correlates with the torque, so a given moment on the same subject, a constant muscle energy consumption rate, and the time muscle fatigue required is related with the torque.