A study of stiffness protocol as exemplified by testing of a burst fracture model in sagittal plane.
A study of stiffness protocol as exemplified by testing of a burst fracture model in sagittal plane.
复制标题
以矢状面爆裂骨折模型测试为例的刚度协议研究。
DOI：
10.1097/00007632-200011010-00006
复制
发表时间：
2000
期刊：
影响因子：
3
通讯作者：
Krag,M
中科院分区：
文献类型：
--
作者：
Panjabi,MM;Kato,Y;Hoffman,H;Cholewicki,J;Krag,M
研究设计：腰椎节段的体外生物力学研究。目的：研究刚度试验方案的特征。背景资料概要：在体外研究中，使用柔韧性方案，施加力并测量运动;不需要指定旋转中心。在使用刚度协议的研究中，测量力并施加运动。这需要指定旋转中心。许多生物力学研究的脊柱，但缺乏明确的这两个测试协议是适当的，以实现一定的studyobjective.Methods。五椎骨腰椎标本爆裂骨折中椎骨（L1）被使用。特殊设计的装置施加屈曲和伸展旋转围绕五个旋转中心位于前后线通过L1的中间。最大力矩为4 Nm.Results.The作者发现载荷-位移曲线，运动范围，和中性区获得的五个中心的旋转是显着不同的。与位于前纵韧带和棘突尖端的旋转中心相比，位于后纵韧带的旋转中心产生了更大的运动范围和中性区（P< 0.01）。这里显示的是载荷-位移曲线的显著变化，取决于旋转中心位置的选择。某些旋转中心位置可能会阻碍脊柱的自然运动，并可能导致组织损伤。
Study Design.An in vitro biomechanical study of lumbar spine segments.Objective.To study the characteristics of the stiffness test protocol.Summary of Background Data.In an in vitro study using a flexibility protocol, forces are applied and motions are measured; no center of rotation needs to be specified. In a study using a stiffness protocol, the forces are measured and the motions are applied. This does require the center of rotation to be specified. Many biomechanical studies of the spine are available, but there is lack of clarity concerning which of these two test protocols is appropriate to achieve a certain study goal.Methods.Five-vertebrae lumbar spine specimens with burst fractures in the middle vertebrae (L1) were used. Specially designed apparatus applied flexion and extension rotations around five centers of rotations located on anteroposterior line through the middle of L1. Maximum moment of 4 Nm was applied.Results.The authors found load-displacement curves, ranges of motion, and neutral zones obtained at the five centers of rotations to be markedly different. The center of rotation located at the posterior longitudinal ligament produced large range of motion and neutral zones in comparison to the centers of rotation located at the anterior longitudinal ligament and the spinous process tip (P< 0.01).Conclusions.The stiffness protocol requires that a center of rotation be specified. Shown here is the significant variability in the load-displacement curves, depending on the choice of the location of the center of rotation. Certain center of rotation locations may block the natural motions of the spine and may result in tissue damage.