The estimation of the body’s center of mass (CoM) trajectory is typically obtained using force platforms, or optoelectronic systems (OS), bounding the assessment inside a laboratory setting. The use of magneto-inertial measurement units (MIMUs) allows for more ecological evaluations, and previous studies proposed methods based on either a single sensor or a sensors’ network. In this study, we compared the accuracy of two methods based on MIMUs. Body CoM was estimated during six postural tasks performed by 15 healthy subjects, using data collected by a single sensor on the pelvis (Strapdown Integration Method, SDI), and seven sensors on the pelvis and lower limbs (Biomechanical Model, BM). The accuracy of the two methods was compared in terms of RMSE and estimation of posturographic parameters, using an OS as reference. The RMSE of the SDI was lower in tasks with little or no oscillations, while the BM outperformed in tasks with greater CoM displacement. Moreover, higher correlation coefficients were obtained between the posturographic parameters obtained with the BM and the OS. Our findings showed that the estimation of CoM displacement based on MIMU was reasonably accurate, and the use of the inertial sensors network methods should be preferred to estimate the kinematic parameters.

中文翻译：

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准确性评估

通常使用力平台或光电系统（OS）来获取人体的质心（CoM）轨迹的估计值，并将其限制在实验室环境内。磁惯性测量单元（MIMU）的使用可以进行更多的生态评估，并且以前的研究提出了基于单个传感器或传感器网络的方法。在这项研究中，我们比较了两种基于MIMU的方法的准确性。使用由骨盆上的单个传感器（Strapdown积分方法，SDI）以及骨盆和下肢上的七个传感器（生物力学模型，BM）收集的数据，在15位健康受试者执行的六个姿势任务中估算了身体CoM。使用OS作为参考，比较了两种方法的准确性，包括均方根误差（RMSE）和姿势参数估计。在很少或没有振荡的任务中，SDI的RMSE较低，而在CoM位移较大的任务中，BM的性能优于后者。此外，在用BM和OS获得的姿势参数之间获得了更高的相关系数。我们的发现表明，基于MIMU的CoM位移估计是相当准确的，应首选使用惯性传感器网络方法来估计运动学参数。