腰大肌作用力与脊柱伸展应力关系的生物力学实验研究

目的:探讨腰大肌作用力带动脊柱伸展应力的生物力学关系。方法:取家兔12只,分3组,每组4只,解剖后保留枢椎以下完整之脊柱及骨盆、髋关节、上段股骨,不损伤脊柱前、后纵韧带、椎间盘及所附着之腰大肌,保留脊柱背侧的竖脊肌、棘上韧带,置于生物力学拉伸测试仪(日本岛津制作所产AGS-J系列)。上端十字头分别夹枢椎(颈胸腰段)、第1胸椎(胸腰段)和第12胸椎(腰段),下端十字头夹股骨上部;分别作有腰大肌状态下和切断腰大肌状态下,股髋自屈曲位到过伸带动脊柱自屈曲位到过伸位拉伸试验,测定两种不同状态下脊柱各节段的伸展应力(N/mm2)。结果:有腰大肌状态和切断腰大肌状态下,股-髋-脊柱拉伸后脊柱伸展应力分别为:颈胸腰全段平均为306.6675N/mm2:78.7167N/mm2;胸腰段为680.8417N/mm2:373.0375N/mm2;腰段为1990.7944N/mm2:523.0608N/mm2;经统计学分析,具显著性差异,P<0.01。结论:腰大肌作用力对脊柱伸展应力影响显著,颈胸腰段占74.33%、胸腰段占45.21%,腰段占73.73%的伸展应力源自腰大肌。脊柱在腰大肌作用下产生腰椎向腹部的弯曲。

The tension effects of psoas muscle on the extended stress of the spine: biomechanical research

Objective: To study biomechanical effects of psoas muscle on the extended stress of the spine. Methods: 28 rabbits were divided into 3 groups (4 animals for every group). All animals were dissected to keep the spine and the pelvis, hip joint, the upper part of the femur, with the anterior and posterior longitudinal ligaments, intervertebral disk and psoas muscle, erector spinae, and supraspinal ligament attached to it. Spine specimens were fixed to the biomechanical elongation tester (Shimazu AGS-J, Japan) with the upper clipping at the vertebra dentata, T1 and T12 vertebra, the lower clipping at the superior part of thigh bone. Under the different states, keeping or removing psoas muscle, the extended stress (N/mm2)of different segments of spine at the flexed and extended positions of hip joint were measured respectively. Results: For different states, the extended stresses of the spine at the flexed and extended positions were 306.6675 N/mm2 and 78.7167 N/mm2 averagely, 680.8417 N/mm2 and 373.0375 N/mm2 at the thoracolumber segment, 1990.7944 N/mm2 and 523.0608 N/mm2 at the lumbar segment respectively, within the significant difference between two states. Conclusions: The tension of psoas muscle effects the extended stress of the spine severely, especially that of the lumbar segment(73.73%). The lumbar flexure is formed by psoas muscles' stretch.