Effect of the intra-abdominal pressure and the center of segmental body mass on the lumbar spine mechanics - a computational parametric study.
Effect of the intra-abdominal pressure and the center of segmental body mass on the lumbar spine mechanics - a computational parametric study.
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腹内压和节段体重中心对腰椎力学的影响 - 计算参数研究。
DOI：
10.1115/1.4005541
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发表时间：
2012
期刊：
影响因子：
--
通讯作者：
Li,G
中科院分区：
文献类型：
--
作者：
Park,WM;Wang,S;Kim,YH;Wood,KB;Sim,JA;Li,G
确定人体腰椎的生理负荷对于了解腰椎疾病的机制和设计手术治疗至关重要。计算模型已被广泛用于估计模拟功能活动期间脊柱的生理负荷。然而，建模技术中对腹内压（IAP）、上半身和腰段的质心（COM）以及椎骨旋转中心（COR）等生理因素做出了各种假设。系统地了解这些假设将如何影响预测的脊柱生物力学对于提高模拟精度非常重要。在本文中，我们开发了腰骶椎的 3D 特定主题数值模型，包括 T12 和 90 肌肉。当受试者处于负重站立位置时，使用全局收敛优化程序研究 IAP 幅度和 COM 位置对每个运动节段的 COR 以及对关节/肌肉力的影响。数据表明，当IAP为0 kPa且COM位于T12椎体几何中心前方10mm时，连接COR的线显示出比站立姿势腰椎前凸更小的曲率。将 IAP 从 0 kPa 增加到 10 kPa，使 COR 的位置向后移动（从椎间盘 (IVD) 中心前 1.4 ± 8.9 mm 到 IVD 中心后 40.5 ± 3.1 mm），并降低平均关节力（从 0.78 ± 0.11体重 (BW) 至 0.31 ± 0.07 BW) 和整体肌肉力量 (从 349.3 ± 57.7 N 至 221.5 ± 84.2 N）。 COM 相对于 T12 椎体几何中心从 -30mm 到 70mm 的前移引起 COR 的前移（从 IVD 中心后 25.1± 8.3mm 到 IVD 中心前 7.8± 6.2mm）和平均关节力增加（从0.78 ± 0.1 BW 至 0.93 ± 0.1 BW）和肌肉力量（从 348.9 ± 47.7 N至452.9 ± 58.6 N）。因此，为了准确模拟人体脊柱生物力学，考虑 IAP 和正确的 COM 非常重要。本研究的方法和结果可用于设计脊柱损伤和复发的预防策略，并提高康复效率。
Determination of physiological loads in human lumbar spine is critical for understanding the mechanisms of lumbar diseases and for designing surgical treatments. Computational models have been used widely to estimate the physiological loads of the spine during simulated functional activities. However, various assumptions on physiological factors such as the intra-abdominal pressure (IAP), centers of mass (COMs) of the upper body and lumbar segments, and vertebral centers of rotation (CORs) have been made in modeling techniques. Systematic knowledge of how these assumptions will affect the predicted spinal biomechanics is important for improving the simulation accuracy. In this paper, we developed a 3D subject-specific numerical model of the lumbosacral spine including T12 and 90 muscles. The effects of the IAP magnitude and COMs locations on the COR of each motion segment and on the joint/muscle forces were investigated using a global convergence optimization procedure when the subject was in a weight bearing standing position. The data indicated that the line connecting the CORs showed a smaller curvature than the lordosis of the lumbar spine in standing posture when the IAP was 0 kPa and the COMs were 10 mm anterior to the geometric center of the T12 vertebra. Increasing the IAP from 0 kPa to 10 kPa shifted the location of CORs toward the posterior direction (from 1.4 ± 8.9 mm anterior to intervertebral disc (IVD) centers to 40.5 ± 3.1 mm posterior to the IVD centers) and reduced the average joint force (from 0.78 ± 0.11 Body weight (BW) to 0.31 ± 0.07 BW) and overall muscle force (from 349.3 ± 57.7 N to 221.5 ± 84.2 N). Anterior movement of the COMs from −30 mm to 70 mm relative to the geometric center of T12 vertebra caused an anterior shift of the CORs (from 25.1 ± 8.3 mm posterior to IVD centers to 7.8 ± 6.2 mm anterior to IVD centers) and increases of average joint forces (from 0.78 ± 0.1 BW to 0.93 ± 0.1 BW) and muscle force (from 348.9 ± 47.7 N to 452.9 ± 58.6 N). Therefore, it is important to consider the IAP and correct COMs in order to accurately simulate human spine biomechanics. The method and results of this study could be useful for designing prevention strategies of spinal injuries and recurrences, and for enhancing rehabilitation efficiency.