The use of inertial measurement units (IMUs) has gained popularity for the estimation of lower limb kinematics. However, implementations in clinical practice are still lacking. The aim of this review is twofold-to evaluate the methodological requirements for IMU-based joint kinematic estimation to be applicable in a clinical setting, and to suggest future research directions. Studies within the PubMed, Web Of Science and EMBASE databases were screened for eligibility, based on the following inclusion criteria: (1) studies must include a methodological description of how kinematic variables were obtained for the lower limb, (2) kinematic data must have been acquired by means of IMUs, (3) studies must have validated the implemented method against a golden standard reference system. Information on study characteristics, signal processing characteristics and study results was assessed and discussed. This review shows that methods for lower limb joint kinematics are inherently application dependent. Sensor restrictions are generally compensated with biomechanically inspired assumptions and prior information. Awareness of the possible adaptations in the IMU-based kinematic estimates by incorporating such prior information and assumptions is necessary, before drawing clinical decisions. Future research should focus on alternative validation methods, subject-specific IMU-based biomechanical joint models and disturbed movement patterns in real-world settings.

中文翻译：

---

基于惯性传感器的下肢关节运动学：方法学系统综述。

惯性测量单元（IMU）的使用在估计下肢运动学方面已广受欢迎。然而，仍然缺乏临床实践中的实现。这篇综述的目的是双重的，以评估基于IMU的联合运动学估计的方法学要求，以适用于临床环境，并提出未来的研究方向。根据以下纳入标准筛选了PubMed，Web of Science和EMBASE数据库中的研究是否符合条件：（1）研究必须包括对下肢运动学变量的获取方法学描述，（2）运动学数据必须具有（3）研究必须已经针对黄金标准参考系统验证了所实施的方法。有关学习特征的信息，对信号处理特性和研究结果进行了评估和讨论。这项审查表明，下肢关节运动学方法固有地取决于应用。通常用生物力学启发的假设和先验信息来补偿传感器的限制。在做出临床决策之前，有必要通过合并此类先验信息和假设来意识到基于IMU的运动学估计中可能的适应措施。未来的研究应侧重于替代验证方法，基于受试者的，基于IMU的生物力学关节模型以及在现实环境中的运动模式受干扰。通常用生物力学启发的假设和先验信息来补偿传感器的限制。在做出临床决策之前，有必要通过合并此类先验信息和假设来意识到基于IMU的运动学估计中可能的适应措施。未来的研究应侧重于替代验证方法，基于受试者的，基于IMU的生物力学关节模型以及在现实环境中的运动模式受干扰。通常用生物力学启发的假设和先验信息来补偿传感器的限制。在做出临床决策之前，有必要通过合并此类先验信息和假设来意识到基于IMU的运动学估计中可能的适应措施。未来的研究应侧重于替代验证方法，基于受试者的，基于IMU的生物力学关节模型以及在现实环境中的运动模式受干扰。