Study On The Muscular Function Model And Its Application Of Human Lower Extremity

It has drawn a wide attention in the research field of sports biomechanics, sports anatomy, sports physiology and athletic training to study the changes of kinematics and kinetics of the muscular work state during exercise, such as muscular length, its variable velocity and the arm of muscular force. It will do much help not only in penetrating into the law of movement and muscular working characteristics and nerve controlling, but also in drawing the project of muscular strength training. For this purpose, A muscular function model of the lower extremities suited to be applicable on live body has been developed based on the coordinates of muscle attachments of lower extremities(mark of muscles origins and terminations, substitute mark of muscles origins and terminations) and coordinates of joint turning center in the corresponding benchmark coordinates system of segments. The muscular function model can be used not only to rationally assess the muscles′potential enginery of lower limbs in different state, but also to provide dynamic changes in function parameter of lower limbs during body moving. At the same time, the article makes a sample of gait analysis, preliminarily testing the usability and reliability of the model. Main content: 1. Space three-dimensional coordinates of muscle attachments and skeletal morphological marker of lower extremities had been scaled by close shot photography technology(DLT and the Total Station Method) 2. By utilizing skeletal morphological parameter and coordinates of the muscle attachments, regression equation of three-dimensional coordinates in the responding benchmark coordinates system is established through which the muscle attachments of living body could be speculated on. 3. Influence of the knee cap in calculating the length of quadriceps femoris and the arm of force of the knee have been studied, and the emulate equation of three-dimensional coordinates of the point of upper and lower edge of the knee cap according to changes of the knee angle have been established. 4. The muscular function model of the lower extremity had been established according to Bryant angle —which was applied to describe relatively change of the rigid body azimuth generalized coordinates; corresponding software —applied computer analysis system of the muscular function model of the lower extremity was work out. 5. The muscular function of the lower extremity was assessed when it was at standard anatomic attitude. 6. The muscular function change in the lower extremity according to the angle of joint was assessed. 7. Make a sample of the gait analysis, the usability and reliability of the muscular function parameter of the model in body moving analysis was tested, preliminary research combined the muscular function model of the lower extremity with multi-equipment synchronization had been done in methodology. Main conclusion: 1. The study laid a foundation for further complete establishment of the rounded muscular function model of Chinese; the model offered further precise three-dimensional coordinates of the muscle attachments; regression equation of three-dimensional coordinates of the muscle attachments had the higher reliability and dependability. 2.Substitute mark of the muscles origins and terminations , the bogus arm of muscular force and the angle of the muscular function conversion,have important theoretical meaning and applied value in rational assessment of the muscular function. The angle of the muscular function conversion is the sign of function diversion of the muscles, and the sign that muscular shortened or protracted to maximum-point when the bogus arm of muscular force drop to zero. 3.Most lower extremity muscles had the strongest effect on frontal axis, sagittal axis takes the second place, the third is vertical axis. Because of the moving of the segment, muscular function parameters acted to all these axis would be changed correspondingly; not only in quantity, but also in quality. 4. One of the function characters of muscle in the hip joint is that the value for the bogus arm of the muscular force is zero. It indicates that a part of muscle has been working all the time, some of them stopped working because of the disappearing of its function, some of other muscle which did not work at initial stages began to work accompanying the movement of segment during thigh moving in whole range of the hip joint. This is the phenomenon of so-called "function compensation"of muscle in hip joint. 5.At standard anatomic attitude, the iliopsoas, pectineus, adductor longus, adductor brevis,lower part of adductor magnus have the function of inside-revolve to hip joint and gracilis has outside-revolve function. The upper part of the gluteus maximus can function as double joint muscle, and has effect on the bending and extending of knee joint. 6. With the changes of knee angle, the moving track of upper and lower edge point of the knee cap is similarly a parabola; knee cap has important influence on the increase of the arm of force of quadriceps femoris to knee joint; at standard anatomic attitude, knee cap made the length of force arm increase about 2.5 times; the main range that knee cap increase the arm of force is 900-00 when knee joint extended. 7. Experiment that combined the muscular function model of the lower extremity with multi-equipment synchronization proved the higher practicability and reliability of the muscular function. Once the applied computer analysis system of the muscular function model of the lower extremity is perfected, it will be more valuable in application and popularization.