Inertial Sensors for Human Motion Analysis: A Comprehensive Review
Sara García-de-Villa, David Casillas-Pérez, Ana Jiménez-Martín, Juan Jesús García-Domínguez
TL;DR
The paper addresses the need to consolidate knowledge on inertial sensor-based human motion analysis by systematically surveying IMU literature up to Aug 2022. It analyzes sensor configurations, target motion units, applications, algorithms (especially sensor fusion and ML), validation, and subject demographics, highlighting a shift toward 3D, full-body kinematics and sparse IMU strategies. Key findings show prevalent use of EKF/KF-based fusion, rising DL/LSTM/CNN methods, and RMSE improvements in ML approaches, though data availability remains a bottleneck. The study underscores the practical impact of enabling in-field motion analysis beyond costly optical systems, while calling for standardized datasets and broader population validation to enable generalizable, clinically relevant solutions.
Abstract
Inertial motion analysis is having a growing interest during the last decades due to its advantages over classical optical systems. The technological solution based on inertial measurement units allows the measurement of movements in daily living environments, such as in everyday life, which is key for a realistic assessment and understanding of movements. This is why research in this field is still developing and different approaches are proposed. This presents a systematic review of the different proposals for inertial motion analysis found in the literature. The search strategy has been carried out on eight different platforms, including journal articles and conference proceedings, which are written in English and published until August 2022. The results are analyzed in terms of the publishers, the sensors used, the applications, the monitored units, the algorithms of use, the participants of the studies, and the validation systems employed. In addition, we delve deeply into the machine learning techniques proposed in recent years and in the approaches to reduce the estimation error. In this way, we show an overview of the research carried out in this field, going into more detail in recent years, and providing some research directions for future work
