RESUMO
[Objective]To investigate the biomechanical pathogenesis of lumbar spondylolysis,and to provide theoretical basis and scientific foundation for the treatment prevention of lumbar spondylolysis.[Method]The three dimension analytical method of finite element was used to set up a 3-D finite element model of whole lumbar vertebral column and to investigate the stress distribution of seven different posture in isthmus of lumbar spine.[Result]The stress of vertebral isthmus increased from L_(1~5) gradually.The concentration phenomenon of the stress prominently appeared in anteflexion and postextension,with the largest postextension position.[Conclusion]Spondylolysis may be caused by the long-term hazard stress on the lumbar isthmus,in high relation with postextension of lumbar spine.