Research on Human Motion Test Based on Biomechanical Sensors Using Electromyography and Pressure Detection Systems

With the continuous development of science and technology, the study of biomechanics in human movement is deepening.Sports biomechanics is a discipline which combines biology with kinematics to study the laws of human movement [1].Human movement is completed through the control of the relevant parts of the body, with features of complexity, diversity and flexibility.Earlier researches on human movement were generally realized through the observation and analysis of moving videos or moving images.By extracting and tracking the contours of the body during movement and analyzing the obtained data, the human action is determined [2].However, the early research on human motion through video images only stays on the twodimensional level and can not comprehensively analyze the characteristics of human motion from the three-dimensional perspective.With the development of materials science and biology, it has been found that electrical signals would be generated during muscle contraction and relaxation during human movement.The method of collecting human motion information based on electromyogram (EMG) signals was proposed.But in the early stage, electrodes were inserted into muscles to collect EMG signals.This method did too much harm to human body and caused movement distortion and large errors in the collected signal data.Although the acquisition of surface EMG signals appeared later avoids electrode insertion and improves safety, EMG signals are relatively weak and vulnerable to external factors.The emergence of piezoelectric materials provides a new method for collecting motion information of human muscles.This paper collected motion information of human muscles using Polyvinylidene Fluoride (PVDF) piezoelectric material.When piezoelectric material was deformed under pressure, electric charge would generate.The larger the deformation, the larger the charge.The deformation of human muscles during movement will produce pressure on objects close to the surface.Therefore, PVDF was served as a sensor to collect the motion information of human muscles.Comparing with the EMG signal method, the method adopted in this paper was safer, more stable and more accurate as the electrode as the electrode was unnecessary to be inserted, piezoelectric material which is lowly sensitive to external factors was