摘要
目的研究胸腰椎节段(T12-L1-L2)屈曲过程中躯干肌肉力的大小及其对椎体应力的影响。方法建立T12-L1-L2节段三维有限元模型,体外生物力学实验资料验证模型有效性。以轴向随动载荷代替节段间局部肌肉力作用。分别在T12-L1-L2节段屈曲0°、5°、10°、15°时,模拟上身重力(260N)、竖脊肌力以及随动载荷(0、100、200N)作用,观察竖脊肌力、椎体表面von Mises应力变化。结果随着T12-L1-L2节段屈曲角度增大,竖脊肌力和椎体表面von Mises应力随之逐渐增大,而随动载荷对椎体表面von Mises应力影响不明显。如果忽略所有肌肉力作用,模型在纯弯矩作用下屈曲相同角度,椎体表面von Mises应力明显降低。结论脊柱生物力学研究不能忽视周围肌肉力的作用,屈曲角度和背侧肌肉力对椎体应力有明显影响。
Objective To investigate the trunk muscle strengths during flexion of the thoracolumbar spine （T12, L1 ＆ L2） and to determine their impacts on vertebral body stress. Methods A three-dimensional finite element model of the thoracolumbar spine was created and validated using experimental data from in vitro measurements on cadaver specimens. We used caudal follower load as an alternative to intra-segmental muscle strength. The model was loaded with mimicked upper body weight （260 N）, compressive follower loads （0, 100, and 200 N, respectively） to account for the local muscle strengths, and a force in the M. erector spinae. The force in the M. erector spinae and yon Mises stress in the vertebral body were estimated during flexion at 0°, 5°, 10°, and 15° in the thoracolumbar spine. Results The flexion angle and the strengths in the M. erector spinae showed strong impacts on the stress in vertebral bodies while the follower loads did not. Given that all the muscle strengths were negligible, the stress in the vertebral body would considerably be reduced when a pure moment is applied. Conclusion This study confirms that the muscle strengths should not be neglected for biomechanical studies of the spine.
出处
《中国药物与临床》
CAS
2007年第12期904-907,共4页
Chinese Remedies & Clinics
基金
山西医科大学校青年基金资助项目(200503)
关键词
胸椎
腰椎
肌收缩
应力
物理
有限元分析
Thoracic vertebrae
Lumbar vertebrae
Muscle contraction
Stress, mechanical
Finite element analysis
