Towards Inertial Sensor Based Mobile Gait Analysis: Event-Detection and Spatio-Temporal Parameters
by
Wolfgang Teufl 1,2,*
, Michael Lorenz 1, Markus Miezal 1, Bertram Taetz 1, Michael Fröhlich 2 and Gabriele Bleser 1
Wolfgang Teufl 1,2,*, Michael Lorenz 1, Markus Miezal 1, Bertram Taetz 1, Michael Fröhlich 2 and Gabriele Bleser 1
1
Junior Research Group wearHEALTH, Technische Universität Kaiserslautern, Gottlieb-Daimler-Str. 48, 67663 Kaiserslautern, Germany
2
Department of Sports Science, Technische Universität Kaiserslautern, Erwin-Schrödinger-Str. 57, 67663 Kaiserslautern, Germany
*
Author to whom correspondence should be addressed.
Sensors 2019, 19(1), 38; https://doi.org/10.3390/s19010038
Received: 24 October 2018 / Revised: 14 December 2018 / Accepted: 19 December 2018 / Published: 22 December 2018
(This article belongs to the Special Issue Wireless Body Area Networks and Connected Health)
The aim of this study was to assess the validity and test-retest reliability of an inertial measurement unit (IMU) system for gait analysis. Twenty-four healthy subjects conducted a 6-min walking test and were instrumented with seven IMUs and retroreflective markers. A kinematic approach was used to estimate the initial and terminal contact events in real-time. Based on these events twelve spatio-temporal parameters (STP) were calculated. A marker based optical motion capture (OMC) system provided the reference. Event-detection rate was about 99%. Detection offset was below 0.017 s. Relative root mean square error (RMSE) ranged from 0.90% to 4.40% for most parameters. However, the parameters that require spatial information of both feet showed higher errors. Step length showed a relative RMSE of 6.69%. Step width and swing width revealed the highest relative RMSE (34.34% and 35.20%). Test-retest results ranged from 0.67 to 0.92, except for the step width (0.25). Summarizing, it appears that the parameters describing the lateral distance between the feet need further improvement. However, the results of the validity and reliability of the IMU system encourage its validation in clinical settings as well as further research.
View Full-Text
Keywords:
accelerometer; gyroscope; inertial measurement unit; ambulatory motion analysis; gait parameters; wearable sensors
▼
Show Figures
Figure 1
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited
MDPI and ACS Style
Teufl, W.; Lorenz, M.; Miezal, M.; Taetz, B.; Fröhlich, M.; Bleser, G. Towards Inertial Sensor Based Mobile Gait Analysis: Event-Detection and Spatio-Temporal Parameters. Sensors 2019, 19, 38.
Show more citation formats
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.
