This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.ĭata Availability: All relevant data are within the manuscript and its Supporting Information files. Received: AugAccepted: FebruPublished: February 28, 2019Ĭopyright: © 2019 Teufl et al. PLoS ONE 14(2):Įditor: John Leicester Williams, University of Memphis, UNITED STATES The high validity of the results encourages further development and the extension of the present approach into clinical settings.Ĭitation: Teufl W, Miezal M, Taetz B, Fröhlich M, Bleser G (2019) Validity of inertial sensor based 3D joint kinematics of static and dynamic sport and physiotherapy specific movements.

The present study revealed a valid IMU-based approach for the measurement of 3D joint kinematics in functional movements of varying demands. Hip flexion revealed the highest average RMSE in all tasks (4.87°– 8.27°). The second evaluation showed an increase in the RMSE of 2.28°– 2.58° on average for all joints and tasks. Mean CMC values ranged from 0.77 to 1 over all joint angles and all tasks. The more dynamic task, CMJ, revealed error measures approximately 1° higher than the remaining tasks. The first evaluation revealed means for RMSE and ROME for all joints and tasks below 3°. First, the IMU data was compared to OMC data based on marker clusters and, second based on skin markers attached to anatomical landmarks. To evaluate the validity of IMU-based 3D joint kinematics, root mean squared error (RMSE), range of motion error (ROME), Bland-Altman (BA) analysis as well as the coefficient of multiple correlation (CMC) were calculated. Only the technical error based on algorithm performance was considered, incorporating OMC data for the calibration, initialization, and a biomechanical model.

A marker based OMC system served as a reference. The IMU kinematics was calculated using a recently-described sensor-fusion algorithm. They performed bilateral squats (SQ), single-leg squats (SLS) and countermovement jumps (CMJ). Twenty-eight healthy subjects participated in this study. The aim of this study was to validate IMU-based 3D joint kinematics of the lower extremities during different movements. However, in recent years, inertial measurement units (IMU) have become a promising alternative. Optical motion capture systems (OMC) are considered the gold standard in motion analysis. 3D joint kinematics can provide important information about the quality of movements.

Visual 3d lower body