屈髋屈膝按压法作用于骨盆的三维有限元分析

目的 应用有限元法研究仰卧位屈膝屈髋按压法对骨盆应力及骶髂关节应变分布特点的影响，讨论该手法扳动整个骶髂关节的可能性。方法 利用CT图像建立正常骨盆三维有限元模型。根据手法原理，将屈膝屈髋按压法分解为两个方向的力，将这两个力加载于三维有限元模型并进行计算分析，得到该加载下骨盆应力和骶髂关节应变的分布情况。结果 加载模拟手法后，骨盆的主要应力位于骶髂关节前下1/3处、坐骨大切迹及臀下线和臀前线的中1/3；骶髂关节的最大应变主要位于骶髂关节的后上缘、后下缘及上缘中部1/2。结论 屈膝屈髋按压法只能扳动骶髂关节的下1/3处，而不能扳动整个骶髂关节。
Objective To investigate the influence from compressing manipulation by flexing hip and knee in supine position on stress distributions in the pelvis and strain distributions in the sacroiliac joints by 3D finite element method, and discuss the possibility of moving the whole sacroiliac joints under such manipulation. Methods A 3D finite element model of the normal pelvis was constructed based on CT images. According to the manipulation principle, the compressing force in flexing hip and knee was decomposed in two directions, and loaded on the 3D finite element model to calculate stress of the pelvis and strain of the sacroiliac joints. Results Under the loading of simulative manipulation, stress of the pelvis was mainly located at 1/3 part of the anterior inferior of the sacroiliac joints, the greater sciatic notch, and the middle 1/3 part of the inferior and anterior of gluteal lines. The maximum strain of the sacroiliac joints was mainly located in the posterior superior, posterior inferior and central 1/2 part of the sacroiliac joints. Conclusions The compressing manipulation by flexing hip and knee can only move 1/3 part of the interior of the sacroiliac joints, rather than the whole of the sacroiliac joints.