Optimization of IMU Sensor Placement for the Measurement of Lower Limb Joint Kinematics

There is an increased interest in using wearable inertial measurement units (IMUs) in clinical contexts for the diagnosis and rehabilitation of gait pathologies. Despite this interest, there is a lack of research regarding optimal sensor placement when measuring joint kinematics and few studies whic...

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Main Authors: Wesley Niswander, Wei Wang, Kimberly Kontson
Format: Article
Language:English
Published: MDPI AG 2020-10-01
Series:Sensors
Subjects:
Online Access:https://www.mdpi.com/1424-8220/20/21/5993
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author Wesley Niswander
Wei Wang
Kimberly Kontson
author_facet Wesley Niswander
Wei Wang
Kimberly Kontson
author_sort Wesley Niswander
collection DOAJ
description There is an increased interest in using wearable inertial measurement units (IMUs) in clinical contexts for the diagnosis and rehabilitation of gait pathologies. Despite this interest, there is a lack of research regarding optimal sensor placement when measuring joint kinematics and few studies which examine functionally relevant motions other than straight level walking. The goal of this clinical measurement research study was to investigate how the location of IMU sensors on the lower body impact the accuracy of IMU-based hip, knee, and ankle angular kinematics. IMUs were placed on 11 different locations on the body to measure lower limb joint angles in seven participants performing the timed-up-and-go (TUG) test. Angles were determined using different combinations of IMUs and the TUG was segmented into different functional movements. Mean bias and root mean square error values were computed using generalized estimating equations comparing IMU-derived angles to a reference optical motion capture system. Bias and RMSE values vary with the sensor position. This effect is partially dependent on the functional movement analyzed and the joint angle measured. However, certain combinations of sensors produce lower bias and RMSE more often than others. The data presented here can inform clinicians and researchers of placement of IMUs on the body that will produce lower error when measuring joint kinematics for multiple functionally relevant motions. Optimization of IMU-based kinematic measurements is important because of increased interest in the use of IMUs to inform diagnose and rehabilitation in clinical settings and at home.
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spelling doaj.art-9275312f1b4944aba7addb867f916fda2023-11-20T18:11:30ZengMDPI AGSensors1424-82202020-10-012021599310.3390/s20215993Optimization of IMU Sensor Placement for the Measurement of Lower Limb Joint KinematicsWesley Niswander0Wei Wang1Kimberly Kontson2Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, MD 20993, USADivision of Clinical Evidence and Analysis 2, Office of Clinical Evidence and Analysis, Office of Product Evaluation and Quality, Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, MD 20993, USAOffice of Science and Engineering Laboratories, Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, MD 20993, USAThere is an increased interest in using wearable inertial measurement units (IMUs) in clinical contexts for the diagnosis and rehabilitation of gait pathologies. Despite this interest, there is a lack of research regarding optimal sensor placement when measuring joint kinematics and few studies which examine functionally relevant motions other than straight level walking. The goal of this clinical measurement research study was to investigate how the location of IMU sensors on the lower body impact the accuracy of IMU-based hip, knee, and ankle angular kinematics. IMUs were placed on 11 different locations on the body to measure lower limb joint angles in seven participants performing the timed-up-and-go (TUG) test. Angles were determined using different combinations of IMUs and the TUG was segmented into different functional movements. Mean bias and root mean square error values were computed using generalized estimating equations comparing IMU-derived angles to a reference optical motion capture system. Bias and RMSE values vary with the sensor position. This effect is partially dependent on the functional movement analyzed and the joint angle measured. However, certain combinations of sensors produce lower bias and RMSE more often than others. The data presented here can inform clinicians and researchers of placement of IMUs on the body that will produce lower error when measuring joint kinematics for multiple functionally relevant motions. Optimization of IMU-based kinematic measurements is important because of increased interest in the use of IMUs to inform diagnose and rehabilitation in clinical settings and at home.https://www.mdpi.com/1424-8220/20/21/5993motion captureIMUjoint kinematicsgait
spellingShingle Wesley Niswander
Wei Wang
Kimberly Kontson
Optimization of IMU Sensor Placement for the Measurement of Lower Limb Joint Kinematics
Sensors
motion capture
IMU
joint kinematics
gait
title Optimization of IMU Sensor Placement for the Measurement of Lower Limb Joint Kinematics
title_full Optimization of IMU Sensor Placement for the Measurement of Lower Limb Joint Kinematics
title_fullStr Optimization of IMU Sensor Placement for the Measurement of Lower Limb Joint Kinematics
title_full_unstemmed Optimization of IMU Sensor Placement for the Measurement of Lower Limb Joint Kinematics
title_short Optimization of IMU Sensor Placement for the Measurement of Lower Limb Joint Kinematics
title_sort optimization of imu sensor placement for the measurement of lower limb joint kinematics
topic motion capture
IMU
joint kinematics
gait
url https://www.mdpi.com/1424-8220/20/21/5993
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AT weiwang optimizationofimusensorplacementforthemeasurementoflowerlimbjointkinematics
AT kimberlykontson optimizationofimusensorplacementforthemeasurementoflowerlimbjointkinematics