Biomechanical Modeling And Muscle Force Prediction Analysis Of Human Upper Limb

With the aggravation of the aging problem, the number of stroke patients is increasing year by year. How to help the patients recover their motor function quickly and effectively has been a hot issue in the field of rehabilitation medicine. Muscle is the source of the power of human motion, whose performance determines the limb movement abilities, therefore, the research and improvement of the mechanical properties of muscle have become the focus in this field. In addition, muscle mechanics has been used in many fields such as biomechanics,sports and robots in different degrees. So, based on the analysis of some research results in related fields, this paper presents an analytical method which is from the outside to the inside,and realizes the modeling and analysis of muscle mechanical properties.By analyzing the structure, muscle composition and movement characteristics of elbow joint, and introducing elbow joint damping factor, a dynamic model of elbow joint skeletal muscle system with damping is established. The relationship between muscle force and external factors such as joint motion, joint flexion velocity and joint damping coefficient is analyzed. Then, the primary and secondary factors influencing the size of muscle force are determined by the orthogonal test method.Based on the Hill model and the scaling principle of human body, a muscle force prediction model for different people is established, and its accuracy and generality are verified by the OpenSim simulation platform. The relationship between muscle force and internal factors such as muscle fiber length, muscle fiber shrinkage rate and the degree of muscle activation is analyzed. Then, the primary and secondary factors influencing the size of muscle force are determined by the orthogonal test method.By analyzing the mechanism and characteristics of EMG signal, the time domain analysis of the EMG signal is carried out by experiments. In the form of piecewise function consisting of exponential function and linear function, a calculation model of the degree of muscle activation is established, and its accuracy is verified by the OpenSim simulation platform. Based on this model, the experiments and analysis at different flexion extension angles, different flexion extension speeds and different mass loads are performed.An experimental platform consisting of a dSPACE real-time simulation system, a computer,a FAB motion capture system,an EMG signal sensor and a tester is set up, and the verification experiment of muscle force prediction model is completed. Moreover, the experiments of elbow flexion and extension movement are performed under the condition of different flexion extension angles, different flexion extension speeds, different mass loads and so on, and combining with muscle force calculation model, the processing and analysis of muscle force is carried out. Finally, the experimental results prove the rationality of the theoretical analysis.