Constrained testing conditions affect the axial rotation response of lumbar functional spinal units
Constrained testing conditions affect the axial rotation response of lumbar functional spinal units
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DOI：
10.1097/00007632-199805150-00016
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发表时间：
1998-05-15
期刊：
影响因子：
3
通讯作者：
Nolte, LP
中科院分区：
文献类型：
--
作者：
Grassmann, S;Oxland, TR;Nolte, LP
研究设计。使用约束和非约束方法对人类尸体脊柱标本进行轴向旋转测试。目的。确定约束方法影响功能性脊柱单元在腰椎和腰骶骨水平的轴向旋转反应的程度。背景数据摘要。关于不同测试方法的适当性，文献中存在很大争议。目前还没有发现客观地检验约束对轴向旋转行为的影响的研究。方法。使用受约束和无约束方法对十个人类尸体脊柱标本（五个 L3-L4、五个 L5-S1）进行轴向旋转测试。在无约束测试中，对上椎骨施加纯力矩，并使用光电摄像系统测量其完整的三维运动。在约束试验中，将标本围绕椎体内的五个旋转轴位置分别加载到定轴伺服液压试验机中，并测量旋转运动的结果。约束测试中的旋转角度在五个旋转轴位置之间没有差异。然而，五个轴位置的最大旋转比最小旋转大约大 40%，存在显着差异。无约束测试的轴向旋转运动始终小于约束测试中测量的最大旋转。然而，使用螺旋运动轴的总旋转角度与约束角度没有显着差异。结论。最大和最小旋转角度之间的巨大差异表明功能脊柱单元在轴向旋转中的行为对轴的位置敏感，但轴的位置是不可重复的。这支持在脊柱测试中使用不受约束的方法。
Study Design. Human cadaveric spine specimens were tested in axial rotation using constrained and unconstrained methods.Objectives. To determine the degree to which constrained methods affect the response of the functional spinal unit in axial rotation at lumbar and lumbosacral levels.Summary of Background Data. A substantial controversy exists in the literature regarding the appropriateness of different testing methods. No study has been found in which the effect of constraint on axial rotation behavior was objectively examined.Methods. Ten human cadaveric spine specimens (five L3-L4, five L5-S1) were tested in axial rotation, using both constrained and unconstrained methods. In the unconstrained test, pure moments were applied to the upper vertebra, and its complete three-dimensional motion was measured using an optoelectronic camera system. In the constrained test, the specimens were loaded in a fixed-axis servohydraulic test machine individually around five rotational axis positions within the vertebral body, and the rotational motion was measured.Results. The rotational angles in the constrained tests were not different among the five rotational axis positions. However, the maximum rotation from the five axis positions was approximately 40% greater than the minimum rotation, a significant difference. The axial rotational motion of the unconstrained tests was always less than the maximum rotation measured in the constrained test. However, the total rotational angle using the helical axis of motion was not significantly different from the constrained angles.Conclusions. The large differences between maximum and minimum rotation angles demonstrate that the behavior of the functional spinal unit in axial rotation is sensitive to the axis's position but the location of the axis is not repeatable. This supports the use of unconstrained methods in spinal testing.