The Biomechanical Study Of Lumbar Simulated Muscles In The Process Of Horizontal Impact

With the development of traffic enterprise,the traffic trauma jumped to the fourth place in the top five causes of death in china.Among the traffic trauma,the epidemiology and clinical statistics documents of traffic trauma have mentioned that the spine injuries accounted for 6%of all the traffic traumas.So we should play more emphasis on the universality and poor prognosis of the spine injuries.In the course of transport,the most frequent impact loading are Chest-back(such as motor vehicles rear impact) and head-pelvis(such as military aircraft ejection) impact loading.The domestic studies are more centered on the Chest-back impact loading and less on the head-pelvis impact loading.Although the muscles constitute the active system for the stabilization of the spine,little researcher consider the role of muscles in the process of impact.It is difficult to simulate the role of muscles in vitro experiment,so the documents about the role of muscle for the stability are few.The object of our research is to approach the role of lumbar muscles forces on the stabilization of spine in the process of transversal impact by using the muscle simulation apparatus.This research include:1.analyze the biomechanical role of muscles on the transversal impact of lumbar by the muscle simulation apparatus;2.to visualizate the lumbar and depending structures by a new workstation.Materials and Methods1.Twenty-four fresh porcine lumbar spines were randomly divided into two groups:one group were fixed with muscle simulation apparatus;another group were not fixed with it;then,each group were randomly separated into two groups again: two groups were imposed on 40J or 80J impact energy by CZZ-â…¡human impact test machine respectively.Roentgenograms and macroscopy anatomy examine and three-dimensional movement were carried out before and after impact.The Paired-samples t test were used to analyze the three-dimensional movement data.2.Import the digital human data into the Dextroscope workstation and convert the data from 16 bit to 8 bit,then Delete superfluous part of the image,diminute the data set,so as easy to visualize the process.The data were loadered to VR environment so as to visualizate the ct data.Then we adjusted the transparency,contrast and other values,reconstructed the lumbar,erector muscle of spine,major psoas muscle,lumbar quadrate muscle,lumbar quadrate muscle and inferior caval vein respectively and assign these into different color.All the reconstructed parts were synthesized into one manipulation interface.Results1.The three-dimension motion showed that the ROM of group with no simulated muscles in the direction of flexion and extension significantly increased after 40J impact energy loading.When impacted by 80J energy,the ROM of six directions significantly increased.The group with simulated muscles only significantly increases in the direction of right rotation after 40J impact energy loading.When impacted by 80J energy,the direction of extension and right rotation increase significantly.The roentgenograms showed all the lumbar were not injured after 40J impact energy loading and most of lumbar in the group with no simulated muscles were fractured after 80J impact energy loading.Macroscopic anatomy showed that the group with no simulated muscles show the injuries of supraspinal ligament and interspinal ligaments after 40J impact energy loading,and injuries of lumbar fracture,articulations zygapophysiales capsule and longitudinal ligament after 80J impact energy loading..But the group with simulated muscles only showed the injuries of supraspinal ligament and interaspinal ligaments.2.We have constructed the visualization model of lumbar and dependency structures by dextroscope.The reconstructed image of lumbar and dependency structures can show the 3D spatial structure and rotate continuous on any plane.The image also can be cut on any plane and show separately and universally.Conclusion1.The research demonstrated that the simulated muscles of L₄-L₅ can active decrease ROM(the range of motion) of extension-flexion,and diminish the injury of adjacent structures.So the simulated muscles of L₄-L₅ segment can guard the lumbar and adjacent structures.2.Dextroscope is good reconstruction software.The visualization model of lumbar and dependency structures have following dominances:1,it can rotate by continuous on any plane.2,The image also can be cut on any plane.3,we can do some interactive operation.4,we can take photograph of the operational procedure,and then export it to explain before operation and clinic teach.