| Objective:To compare and analyze the biomechanical changes of lumbar vertebrae with different elbow pressing methods,to explore the possible mechanism of elbow pressing method and the most suitable angle of elbow pressing method,so as to provide some experimental basis for improving the clinical effect.Methods:First,the normal lumbar finite element model was established,and the left and back protrusion of lumbar intervertebral disc was established by changing the elastic modulus and Poisson's ratio of nucleus pulposus and annulus fibrosus matrix.The verification of the model was completed.The projection of the protrusion's body surface was used as the pressing position,the pressing force was 400 N,the pressing angle was left to right,and the pressing was simulated once every 15°.Under the different angle elbow pressing method,the positive The distribution of stress and displacement in the finite element model of lumbar disc herniation.Results:1.Stress analysis of vertebra and posterior structure: under different angle elbow pressing method,the stress of vertebra and posterior structure of normal lumbar model and lumbar disc herniation model are mainly concentrated in L5 bilateral pedicle,bilateral facet joint and simulated pressing position.Compared with the normal model,the stress level of lumbar disc herniation model is lower,but the stress concentration range is larger.For the model of lumbar disc herniation,when the pressing angle is 15°~45°,the stress is mainly concentrated on the right side;when the pressing angle is 60°,the stress is relatively concentrated on both sides;when the pressing angle is 75°~165°,the stress is mainly concentrated on the left side;in the elbow pressing method with different angles,the stress of bilateral small joints of the normal model is significantly different,protruding the bilateral small joints of the model and the left vertebrae of L5 the stress of the arch root was significantly different.2.Stress analysis of intervertebral disc:under different angle elbow pressing method,the stress of normal intervertebral disc and herniated intervertebral disc are mainly concentrated at the back and both sides of the intervertebral disc;among them,under different angle elbow pressing method,the stress o f herniated model intervertebral disc is significantly different.3.Analysis of displacement of vertebra and posterior structure:under different angle elbow pressing method,the displacement of vertebra and posterior structure of normal lumbar model and lumbar disc herniation model are mainly concentrated with L4 posterior structure.Compared with normal lumbar model,the displacement of lumbar disc herniation model is smaller,but the displacement concentration range is more.For the model of lumbar disc herniation,when the pressing angle is 15°~60°,the displacement direction of the left inferior articular process of L4 is right,forward and up;when the pressing angle is 75°~90°,the displacement direction of the left inferior articular process of L4 is forward and up;when the pressing angle is 105°~165°,the displacement direction of the left inferior articular process of L4 is left,forward and up;among them,when the elbows are at different angles,the displacement direction is positive.There was a significant difference in the displacement of L4 left lower articular surface between the normal model and the protruding model.4.Analysis of disc displacement:under different angle elbow pressing method,the displacement distribution trend of normal disc and protrusion disc is roughly the same.Compared with normal disc,the displacement of protrusion disc is smaller and the displacement concentration range is smaller.Among them,for the herniated disc,when the pressing angle is 15°~60°,the displacement direction of the herniated disc is right and forward;when the pressing angle is 75°,the displacement direction of the herniated disc is forward;when the pressing angle is 90°~165°,the displacement direction of the herniated disc is left and forward;among them,under different angle elbow pressing method,the normal model and the herniated model of the disc process.There was significant difference in the displacement of the exit part.Conclusion:1.In the simulated elbow pressing method,the stress concentration range of small joints,edicle,simulated pressing parts and fiber ring in the posterior structure of lumbar disc herniation model is larger than that in the normal lumbar model,and the stress concentration parts are different in different angles,among which,when the pressing a ngle is 15°~45°,the load of manipulation on the affected lumbar spine is smaller.2.The therapeutic mechanism of elbow pressing may be related to the relative displacement of the posterior part of the disc and the facet joint,and the therapeutic effect is better when the angle is 60 °.3.Considering the safety and curative effect of elbow pressing method,when the pressing angle is 45°,the effect is the best. |
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