Establishment Of Lower Lumbar Vertebral Three-dimensional Finite Element Model

Lumbar vertebral as only connection between truck with pelvis burden the largest load on spine column,load gradually enlarge from supper vertebral to low lumbar vertebral. Meanwhile the movement range of lumbar vertebral is too larger than other segment,the details show that degeneration of spine usually happen on the low lumbar vertebral,in that,the research of low lumbar vertebral's biomechanical is valuable in clinic.Now,there are number kind of experiments to study spine biomechanics,four experiment methods are usually used:animal experiment,physical experiment,cadaver experiment and computer simulator experiment,they are all outside-body. By animal experiment we can observe the biology reactive of inherent of organ,but animal's constructions of spine are different with human's,they can not answer the question of human biomechanics. Physical experiment is also limited because it lack of inherent structure of spine. Cadaver experiment can get similar result with vivid body as specimen similar with vivid,but specimens are too expensive,the change character of body is too difficult to simulator. Computer simulator experiment such as finite element can simulator repeatedly. If some parameters are changed it can modeldegenerate of spine.The priciple of finite element is divide body consist with infinite particle into brief finite element which mechanics characters are known. This process called disperse,the model are used to display original body. According structure,material and load,different element (block element,shell element,plate element and cable element et.al) are used. Element connect with each other by notes,and force are transfer through notes,the unknown of inner point of element can calculate by formulator .The object of the research is to develop a three-dimension finite element model of L3-L5 to study the stress distribution of lumbar vertebral when human standing. It composed 5671 nodes,27725 elements and 7 materials. It was be evident the model were reasonable and consistent with test. We look forward that it can be useful for clinical research. Meanwhile the model should be modified and perfected.