A combined passive and active musculoskeletal model study to estimate L4-L5 load sharing
A combined passive and active musculoskeletal model study to estimate L4-L5 load sharing
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DOI：
10.1016/j.jbiomech.2017.04.026
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发表时间：
2018-03-21
影响因子：
2.4
通讯作者：
Rahimi-Moghaddam, T.
中科院分区：
文献类型：
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作者：
Azari, F.;Arjmand, N.;Rahimi-Moghaddam, T.
一些几何细节的腰椎被动有限元(FE)模型已经被开发出来，并在体外加载条件下得到验证。这些模型没有肌肉，因此不能直接用于模拟作用于腰椎关节结构或脊柱植入物的活体载荷条件。将躯干肌肉骨骼(MS)模型在12种静态活动下估计的重力载荷和肌力应用于L4-L5节段的被动有限元模型，以估计模拟活体载荷条件下关节结构(关节盘、韧带和小关节)之间的载荷分配。在每项任务中都计算了一个等效跟随者(FL)，它产生的等同于肌肉力量产生的IDP。结果表明，在活体负荷条件下，被动有限元模型预测的椎间盘内压力(IDPs)与模拟任务下的测量结果非常接近(R-2=0.98，均方根误差RMSE=0.18 Mpa)。计算的等效FL与作用在L4-L5节段上的所有肌力和重力载荷的合力(R-2=0.99，RMSE=58N)吻合较好。因此，作为在被动FE模型研究中表示体内负荷条件的另一种方法，这种FL可以通过现有的内部或商业MS模型来估计。在临床应用和植入物设计中，通常认为被动有限元模型的体外载荷条件不能很好地反映肌肉负荷下的体内载荷条件。因此，应改为使用更现实的活体加载条件。(C)2017爱思唯尔有限公司。保留所有权利。
A number of geometrically-detailed passive finite element (FE) models of the lumbar spine have been developed and validated under in vitro loading conditions. These models are devoid of muscles and thus cannot be directly used to simulate in vivo loading conditions acting on the lumbar joint structures or spinal implants. Gravity loads and muscle forces estimated by a trunk musculoskeletal (MS) model under twelve static activities were applied to a passive FE model of the L4-L5 segment to estimate load sharing among the joint structures (disc, ligaments, and facets) under simulated in vivo loading conditions. An equivalent follower (FL), that generates IDP equal to that generated by muscle forces, was computed in each task. Results indicated that under in vivo loading conditions, the passive FE model predicted intradiscal pressures (IDPs) that closely matched those measured under the simulated tasks (R-2 = 0.98 and root-mean-squared-error, RMSE = 0.18 MPa). The calculated equivalent FL compared well with the resultant force of all muscle forces and gravity loads acting on the L4-L5 segment (R-2 = 0.99 and RMSE = 58 N). Therefore, as an alternative approach to represent in vivo loading conditions in passive FE model studies, this FL can be estimated by available in-house or commercial MS models. In clinical applications and design of implants, commonly considered in vitro loading conditions on the passive FE models do not adequately represent the in vivo loading conditions under muscle exertions. Therefore, more realistic in vivo loading conditions should instead be used. (C) 2017 Elsevier Ltd. All rights reserved.