Zander T, Rohlmann A, Calisse J, Bergmann G
Orthopaedic Hospital of the Free University of Berlin, Oskar-Helene-Heim, Biomechanics Laboratory, Clayallee 229, D-14195, Berlin, Germany.
Clin Biomech (Bristol). 2001;16 Suppl 1:S73-80. doi: 10.1016/s0268-0033(00)00108-x.
To estimate the muscle forces during upper-body inclination and to determine their influence on stress distribution in the annulus fibrosus of the lumbar spine discs.
The muscle forces and stresses were calculated using a non-linear finite element model of the lumbar spine.
Little is known about the influence of muscle forces on the deformation of, and stresses in, the lumbar spine. In most studies, muscle forces are neglected.
Three-dimensional non-linear finite element models of the ligamentous lumbar spine, with and without internal spinal fixators, were created. They were validated by use of experimental data from in vitro measurements on cadaver specimens. In a second step, the influence of muscle forces on stresses in the annulus fibrosus of the lumbar spine discs was investigated in a parameter study. This was done for different inclination angles of the upper-body.
Good agreement between analytical and experimental results proved achievable when loading with pure moments in the three main planes of the lumbar spine. For inclination of the upper-body, the flexion angle clearly has a strong influence on the stresses in the lumbar spine while the influence of local muscles was small. The stress distribution in the discs differed considerably when the muscle forces are neglected and only a pure moment is applied.
This study confirmed earlier ones that have shown that muscle forces should not be neglected when studying the stresses in the lumbar spine. The local dorsal muscles, however, have only a small influence on the stresses in the discs.
For investigations of the biomechanical effects of spinal implants and surgical procedures, experimental or analytical methods are used. Due to the complexity involved, as well as to a lack of information, muscle forces are often neglected. Our study showed that muscles do in fact have a major influence on the mechanical behaviour of the spine and should always be taken into account.
评估上身倾斜时的肌肉力量，并确定其对腰椎间盘纤维环应力分布的影响。
使用腰椎的非线性有限元模型计算肌肉力量和应力。
关于肌肉力量对腰椎变形和应力的影响知之甚少。在大多数研究中，肌肉力量被忽略。
创建了有和没有内部脊柱固定器的韧带性腰椎三维非线性有限元模型。通过对尸体标本进行体外测量获得的实验数据对其进行验证。第二步，在参数研究中调查肌肉力量对腰椎间盘纤维环应力的影响。这是针对上身不同倾斜角度进行的。
当在腰椎的三个主要平面施加纯力矩时，分析结果与实验结果证明可以达成良好的一致性。对于上身倾斜，屈曲角度对腰椎应力有明显的强烈影响，而局部肌肉的影响较小。当忽略肌肉力量而仅施加纯力矩时，椎间盘内的应力分布有很大差异。
本研究证实了早期的研究结果，即研究腰椎应力时不应忽略肌肉力量。然而，局部背部肌肉对椎间盘应力的影响很小。
对于脊柱植入物和手术程序的生物力学效应研究，使用实验或分析方法。由于涉及的复杂性以及信息不足，肌肉力量常常被忽略。我们的研究表明，肌肉实际上对脊柱的力学行为有重大影响，应始终予以考虑。
