Three-Dimensional Finite Element Modeling And Biomechanical Analysis Of Lumbosacral Joint Of Young Female Weightlifters

In the process of weightlifting competition,although there is no direct physical confrontation,the incidence of injury has been high,the sports injury caused by weightlifting can be as high as 2.4-3.3 times / 1000 h training.At present,the waist and knee account for the highest proportion of the common injury sites of weightlifters.The lumbosacral joint of the spine,as the core of the conduction force,is not only the fulcrum of stress compression for a long time,but also the buffer structure that transmits the stress to the pelvis and makes it decompose and transmit to the lower extremity.Young female weightlifters are in the growth and development stage,spinal lumbosacral segment has a unique anatomical characteristics,at present,there are few reports on the characteristics of lumbosacral joint injury and finite element modeling.Based on the CT images of lumbosacral joints of young female weightlifters,this study attempts to construct a finite element model of lumbosacral joints with more complete structure and biomechanical characteristics.The stress and strain of lumbosacral joint and the stress transfer direction of intervertebral disc were analyzed by applying axial compression load to the upper surface of lumbar vertebrae to simulate the athletes' weightlifting posture and to analyze the stress and strain of lumbosacral joint and the stress transfer direction of intervertebral disc.Finally,it was found that when the female weightlifters fully stood up in weightlifting training,when the lumbosacral joint was subjected to axial load,there was obvious deformation in the upper edge of L5 and the anterior part of the intervertebral disc.The maximum deformation was 5.44 mm,and the upper surface of vertebral body and the auricular surface of sacrum were the main stress sites.Under axial load,the stress in the anterior part of the intervertebral disc was significantly higher than that in the posterior part,and that in the left side was significantly higher than that in the right side.the Von-Mises stress transfer direction of the intervertebral disc increased from the left side in the right posterior direction,and the stress concentration point appeared in the posterior part of the annulus fibrosus.This suggests that when the lumbosacral joint is only subjected to axial load,the posterior side of the intervertebral disc may still cause low back pain and even rupture of the posterior annulus fibrosus of the intervertebral disc due to long-term stress concentration.