Influence of body segment parameters and modeling assumptions on the estimate of center of mass trajectory
Influence of body segment parameters and modeling assumptions on the estimate of center of mass trajectory
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DOI：
10.1016/s0021-9290(03)00151-9
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发表时间：
2003-09-01
影响因子：
2.4
通讯作者：
Chiari, L
中科院分区：
文献类型：
--
作者：
Lenzi, D;Cappello, A;Chiari, L
本研究旨在确定身体节段参数和建模假设的不准确性对前后质心（COM）轨迹估计的影响。四种不同的方法，一个基于节段运动学，和三种方法的基础上动力学记录进行了比较，通过模拟。运动模式（安静的立场，踝关节相关的摇摆，髋踝关节相关的摇摆，仰卧起坐和仰卧起坐下来）进行了测试与2D四连杆模型的身体和地面反作用力矢量获得的逆动力学。通过一次对一个或多个参数应用+/- 10%的变化来模拟身体节段参数估计中的误差。这些错误以不同的方式传播到方法之间、同一方法内的参数之间以及任务之间的COM估计位置。运动学为基础的方法是最敏感的身体部分参数，特别是段长度和头臂躯干参数。估计和模拟COM位置之间的均方根误差达到19毫米，在平衡相关的任务和38.3毫米，在仰卧起坐。基于动力学的方法在很大程度上对身体部分参数的不准确性不太敏感。特别地，Zatsiorsky和King（J. Biomech. 31（1998）161），对片段参数完全不敏感。另一方面，基于动力学的方法显示出固有的估计误差，由于基本的模型假设。基于水平力双重积分的方法在挑战此类假设的任务中具有更好的结果，在仰卧起坐中COM位置的最大误差为15 nun。Shimba提出的方法（J. Biomech. 17（1984）53）示出了在给定理想测试条件下对身体节段参数的灵敏度与估计性能之间的最佳折衷。(C)2003 Elsevier Ltd.保留所有权利。
This study sought to determine the effect of inaccuracies in body segment parameters and modeling assumptions on the estimate of antero-posterior center of mass (COM) trajectory. Four different methods, one based on segmental kinematics, and three methods based on kinetic recordings were compared via simulation. Kinematic patterns (quiet stance, ankle-related sway, hip-ankle-related sway, sit-up and sit-up-sit-down) were tested with a 2D four-link model of the body and the ground reaction force vector was obtained by inverse dynamics. Errors in the estimation of body segment parameters were simulated by applying a +/- 10% variation to one or more parameters at a time. These errors propagated differently to the COM estimated location between methods, between parameters within the same method, and between tasks. The kinematics-based method was the most sensitive to body segment parameters, with special regards to segment lengths and head-arms-trunk parameters. Root mean square error between estimated and simulated COM location reached 19 mm in balance-related tasks and 38.3 mm in sit-up-sit-down. The kinetics-based methods were largely less sensitive to inaccuracies in body segment parameters. In particular, the technique proposed by Zatsiorsky and King (J. Biomech. 31 (1998) 161), was completely insensitive to segment parameters. On the other hand the kinetics-based methods showed an intrinsic estimation error, due to the underlying model assumptions. The methods based on the double integration of horizontal force had better outcomes with tasks challenging such assumptions, with a maximal error in COM location of 15 nun in the sit-up-sit-down. The method proposed by Shimba (J. Biomech. 17 (1984) 53) showed the best trade-off between sensitivity to body segment parameters and estimation performances given the ideal test conditions. (C) 2003 Elsevier Ltd. All rights reserved.