A least-squares identification algorithm for estimating squat exercise mechanics using a single inertial measurement unit
A least-squares identification algorithm for estimating squat exercise mechanics using a single inertial measurement unit
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DOI：
10.1016/j.jbiomech.2012.02.014
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发表时间：
2012-05-11
影响因子：
2.4
通讯作者：
Cappozzo, Aurelio
中科院分区：
文献类型：
--
作者：
Bonnet, Vincent;Mazza, Claudia;Cappozzo, Aurelio
这项研究基于从位于下躯干上的单个惯性测量单元收集的数据，研究了在矢状面进行下蹲练习时估计下肢关节运动学的可能性。人体被建模为一个三自由度的平面链，相关的关节角度(踝关节、膝盖和髋关节)用傅立叶级数表示。基于线加速度实测值和估计值与下干角速度之差最小的最小二乘法，解决了相关的分析问题。该方法在10名健康的年轻志愿者(每人10次试验)上得到验证，他们使用测力板和立体摄影测量系统收集参考数据。估算的关节角度与立体摄影测量系统重建的关节角度之间的均方根差小于4，相关系数大于0.99。踝关节合力分量的估计精度约为3%，相关系数r=0.95，而水平力和耦合分量的百分比精度较低。后者的精度与通过逆动力学和立体摄影测量数据结合相同的力学模型估计的影响这些力和耦合分量的精度相似，这表明所提出的算法和测量工具只引入了很小的误差。(C)2012爱思唯尔有限公司。保留所有权利。
This study investigated the possibility of estimating lower-limb joint kinematics during a squat exercise performed in the sagittal plane based on data collected from a single inertial measurement unit located on the lower trunk. The human body was modeled as a three-degrees-of-freedom planar chain and the relevant joint angles (ankle, knee, and hip) are represented by Fourier series. A least-squares approach based on the minimization of the difference between the measured and estimated linear accelerations and the angular velocity of the lower trunk was used to solve the related analytical problem. The approach was validated on ten healthy young volunteers (ten trials each) using a force plate and a stereophotogrammetric system to collect reference data. The root mean square differences between the estimated joint angles and those reconstructed with the stereophotogrammetric system were lower than 4 with correlation coefficients higher than 0.99. The ankle joint resultant vertical force component was estimated with an accuracy of about 3% and a high correlation coefficient of r=0.95, whereas much lower percentage accuracies were found for the horizontal force and couple components. The latter accuracies were similar to those affecting these force and couple components as estimated through inverse dynamics and the stereophotogrammetric data in conjunction with the same mechanical model, which suggests that only minor errors were introduced by the proposed algorithm and measurement tools. (C) 2012 Elsevier Ltd. All rights reserved.