Kim Kyungsoo, Kim Yoon Hyuk, Lee Sukyoung
Department of Mathematics, Kyonggi University, Suwon, Korea.
Acta Bioeng Biomech. 2010;12(4):49-53.
It has been shown experimentally that the load carrying capacity of the spine significantly increases when compressive loads are carried along the follower load (FL) direction. However, it is necessary to modify the current FL concept because a certain amount of shear force is produced during activities in daily life. In this study, a clinically allowable range of shear force was investigated using the modified FL concept. The shear force allowance was defined as the maximum ratio of the shear force to the follower force at each vertebral body center. Then, it was shown that the appropriate shear force allowance was within approximately 0.2 ~ 0.5 from the investigation of the follower forces, the shear forces, and the muscle force coordination. The predicted shear force allowance indicated that the resultant joint force is directed to a certain inside region between a half vertebral body and whole vertebral body.
实验表明，当沿着随动载荷（FL）方向承受压缩载荷时，脊柱的承载能力会显著增加。然而，有必要修改当前的FL概念，因为在日常生活活动中会产生一定量的剪切力。在本研究中，使用修改后的FL概念研究了临床上允许的剪切力范围。剪切力允许值定义为每个椎体中心处剪切力与随动载荷力的最大比值。然后，通过对随动载荷力、剪切力和肌肉力协调性的研究表明，合适的剪切力允许值约在0.2至0.5之间。预测的剪切力允许值表明，合成关节力指向半个椎体和整个椎体之间的某个内部区域。
