Gastrocnemius Muscle Fatigue Muscle Sound Characteristics And Finite Element Modal Analysis

The muscle sound, generated by a mechanical vibration when the Skeletal muscle is shrinking,contains the information about the state of skeletal muscle.The muscle sound is attached importance by the researchers because the measurement of muscle motor unit with muscle sound is non-invasive.The judgment of the state of skeletal muscle with the muscle sound is of great significance to sports training and recovery of sports injury,In this paper,the acoustic signal of the gastrocnemius at heel raised is studied by the power spectral density(PSD).The features of the frequency domain and the Change of the PSD of the acoustic signal in the exercise process are analyzed. The result is following:(1) The energy of acoustic signal of the gastrocnemius at heel raised is largely concentrated in low-frequency of 2.806±0.645Hz～13.249±1.223Hz and the frequency of the peak of the PSD changes with a wavy motion.Peak frequency The peak frequency is higher when the exercise is end than the one at the beginning.(2) Modal analysis is proceeded by ANSYS。Based on the simulation results and actual situation, Y-axial telescoping and Z-axial bending vibration is easy to be inspired when the exercise is proceeding.The two types of major shapes have a certain percentages in low-frequency and the higher frequency the less proportion of the two types of major shapes.The reason that the energy spectrum is concentrated in low-frequency in experiment is the major shapes, Y-axial telescoping and Z-axial bending vibration, that is is easy to be inspired is reduce when the frequency is increase.(3)How the young's modulus and density variations affect the movement of the frequency is analyzed. Simulation results show that the impact of Young's modulus to the change of frequency is larger the the impact of the density.The main reason that the frequency move to the high-frequency with the emergence of sports fatigue is the increase of the Young's modulus...