Instantaneous centers of rotation for lumbar segmental extension in vivo
Instantaneous centers of rotation for lumbar segmental extension in vivo
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DOI：
10.1016/j.jbiomech.2016.12.021
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发表时间：
2017-02-08
影响因子：
2.4
通讯作者：
Zhang, Xudong
中科院分区：
文献类型：
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作者：
Aiyangar, Ameet;Zheng, Liying;Zhang, Xudong
该研究旨在绘制功能性举重任务期间腰部运动节段的瞬时旋转中心（ICR），并检查各节段之间的差异以及举升重量大小引起的变化。 11 名健康参与者将三种不同量级（4.5、9 和 13.5 公斤）的负载从躯干弯曲（类似于 75 度）提升到直立位置，同时通过动态立体 X 射线 (DSX) 系统进行成像。跟踪的腰椎 (L2-S1) 运动数据被处理为高精度 6DOF 椎间 (L2L3、L3L4、L4L5、L5S1) 运动学。 ICR 使用有限螺旋轴法计算。使用混合效应模型评估节段水平和负载大小对前后 (AP) 和上下 (SI) ICR 迁移范围的影响。此外，ICR 被平均到单个旋转中心 (COR)，以评估 COR AP 和 SI 坐标中的段特定差异。发现 L2L3 的 AP 范围明显大于 L3L4 (p=0.02)、L4L5 和 L5S1 (p < 0.001)。与 L2L3 和 L3L4 相比，L4L5 和 L5SI 的平均 ICR SI 位置相对较高（靠近下椎骨的上终板）（p < 0.9）。载荷大小仅对 ICR 迁移范围的 SI 部分有显着影响（13.5 kg > 9 kg 和 4.5 kg；p 分别为 0.049 和 0.017）。所报告的节段特定 ICR 数据例证了腰椎生物力学模型和椎间盘替代物设计的改进输入参数，以及潜在诊断应用的基线参考。 (C) 2017 爱思唯尔有限公司保留所有权利。
The study aimed to map instantaneous centers of rotation (ICRs) of lumbar motion segments during a functional lifting task and examine differences across segments and variations caused by magnitude of weight lifted. Eleven healthy participants lifted loads of three different magnitudes (4.5, 9, and 13.5 kg) from a trunk-flexed (similar to 75 degrees) to an upright position, while being imaged by a dynamic stereo X-ray (DSX) system. Tracked lumbar vertebral (L2-S1) motion data were processed into highly accurate 6DOF inter vertebral (L2L3, L3L4, L4L5, L5S1) kinematics. ICRs were computed using the finite helical axis method. Effects of segment level and load magnitude on the anterior-posterior (AP) and superior-inferior (SI) ICR migration ranges were assessed with a mixed-effects model. Further, ICRs were averaged to a single center of rotation (COR) to assess segment-specific differences in COR AP- and SI-coordinates. The AP range was found to be significantly larger for L2L3 compared to L3L4 (p=0.02), L4L5 and L5S1 (p < 0.001). Average ICR SI location was relatively higher - near the superior endplate of the inferior vertebra - for L4L5 and L5SI compared to L2L3 and L3L4 (p 0.9). Load magnitude had a significant effect only on the SI component of ICR migration range (13.5 kg > 9 kg and 4.5 kg; p=0.049 and 0.017 respectively). The reported segment specific ICR data exemplify improved input parameters for lumbar spine biomechanical models and design of disc replacements, and base-line references for potential diagnostic applications. (C) 2017 Elsevier Ltd All rights reserved.