A Study Of Relationship Between Moment And Electromyography On Human Leg Front Swing Whiplash Action

The contraction of the muscle can provide power for human body motion, so thestudy on the mechanical properties of muscle can contribute to deepening theunderstanding of the nature and regular pattern of human body movement. There is avariety of information on assessment of muscle, and on the mechanical aspects, musclecontraction can make joint rotate to generate torque, which is a quantitative index toassess muscle function. Besides, it also includes electrophysiological indicators ofmuscle movement, such as the surface EMG, which is a series of electrical signalsgenerated at the time of muscle contraction and analysis of corresponding parametersof surface EMG can assess the motorial state of muscle. The relationship betweencontrol muscle torque and electricity in the movement of human lower limb can beconcluded through mechanical modeling, mathematical calculation and methodshuman experiment combination based on Statistical Theory. The informationconcluded through the experiment is helpful to study the characteristics of humanlower limb whiplash movement, ensure the theoretical basis of the actionimplementation, and establish the correct mode of action. At the same time since theacquisition of joint torque is complex and time-consuming and the acquisition ofsEMG is relatively easy, we can build the corresponding relation equation betweentorque and electricity, and it can predict the corresponding joint torque under thecircumstance of obtaining the s EMG, which is of great significance for the analysis ofmotion skill and joint torque.In dynamics, the experiment establishes the model of lower limb chain, analyzesthe experimental video through the three-dimensional video recording and analysissystem, and analyzes the obtaining data using self written Matlab language programpackage to calculate the joint torque of each joint of lower limbs. In electromyography,this research makes an analysis of the EMG signals using the time-frequency index,which makes up the deficiency of previous surface EMG analysis that only focus onthe time domain or frequency domain parameters. Time-frequency analysis is thecombination of the two aspects of time and frequency to describe the signal throughthe function relationship between them, which can reflect the changing trend offrequency in time. Parameters in electromyography, such as the average, median frequency in traditional analysis of surface EMG are generally used in static contraction process, during which the EMG signal is stable and can use the median frequency index. But usually in the actual movement, the muscle contraction is in the process of dynamic contractions, during which the EMG signal is unstable, which makes it necessary to analyze the EMG signal in the process of dynamic contractions based on time-frequency analysis.Through the calculation and analysis of joint torque and surface EMG, this article on the hip, knee joint torque, control of surface EMG and joint angle muscles in the regression equation is established by the stepwise regression method, the specific equation as follows.1, hip equationWhiplash without preliminary swing lower limbs forward whiplash regression equation: Y=108.985+0.143X5-340.914X6+2.469X7Whiplash with passive preliminary swing lower limbs forward whiplash regression equation: Y=127.367-0.033X5+9285.734X6+5.287X7Whiplash with active preliminary swing lower limbs forward whiplash regression equation: Y=180.837+0.113X5+135.710X6+9.479X7Y:hip joint torque X5:rectus femoris instantaneous mean frequence X6:rectus femoris instantaneous mean power X7:hip joint angle2, knee equation Whiplash without preliminary swing lower limbs forward whiplash regression equation: Y=77.475+0.209Xi-0.029X3-0.575X5-3.901X7Whiplash with passive preliminary swing lower limbs forward whiplash regression equation: Y=154.945-2327.523X2+1169.857X4-847.071X6-3.033X7Whiplash with active preliminary swing lower limbs forward whiplash regression equation: Y=54.730+732.971X2-688.835X4-1.711X7Y:knee joint torque X1:rectus femoris instantaneous mean power X2:rectus femoris instantaneous mean frequence X3:vastus medialis instantaneous mean power X4:vastus medialis instantaneous mean frequence X5:vastus lateralis instantaneous mean power X6:vastus lateralis instantaneous mean frequence X7:knee joint angle...