Validation of an Inertial Sensor Algorithm to Quantify Head and Trunk Movement in Healthy Young Adults and Individuals with Mild Traumatic Brain Injury

Wearable inertial measurement units (IMUs) may provide useful, objective information to clinicians interested in quantifying head movements as patients’ progress through vestibular rehabilitation. The purpose of this study was to validate an IMU-based algorithm against criterion data (motion capture) to estimate average head and trunk range of motion (ROM) and average peak velocity. Ten participants completed two trials of standing and walking tasks while moving the head with and without moving the trunk. Validity was assessed using a combination of Intra-class Correlation Coefficients (ICC), root mean square error (RMSE), and percent error. Bland-Altman plots were used to assess bias. Excellent agreement was found between the IMU and criterion data for head ROM and peak rotational velocity (average ICC > 0.9). The trunk showed good agreement for most conditions (average ICC > 0.8). Average RMSE for both ROM (head = 2.64°; trunk = 2.48°) and peak rotational velocity (head = 11.76 °/s; trunk = 7.37 °/s) was low. The average percent error was below 5% for head and trunk ROM and peak rotational velocity. No clear pattern of bias was found for any measure across conditions. Findings suggest IMUs may provide a promising solution for estimating head and trunk movement, and a practical solution for tracking progression throughout rehabilitation or home exercise monitoring.

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Camera and inertial sensor fusion for the PnP problem: algorithms and experimental results

Machine Vision and Applications ◽

10.1007/s00138-021-01219-0 ◽

2021 ◽

Vol 32 (4) ◽

Author(s):

Luigi D’Alfonso ◽

Emanuele Garone ◽

Pietro Muraca ◽

Paolo Pugliese

Keyword(s):

Pose Estimation ◽

Good Accuracy ◽

Inertial Sensor ◽

Experimental Tests ◽

Inertial Measurement Units ◽

Magnetic Vector ◽

Inertial Measurement ◽

The Earth ◽

Measurement Units ◽

Position And Orientation

AbstractIn this work, we face the problem of estimating the relative position and orientation of a camera and an object, when they are both equipped with inertial measurement units (IMUs), and the object exhibits a set of n landmark points with known coordinates (the so-called Pose estimation or PnP Problem). We present two algorithms that, fusing the information provided by the camera and the IMUs, solve the PnP problem with good accuracy. These algorithms only use the measurements given by IMUs’ inclinometers, as the magnetometers usually give inaccurate estimates of the Earth magnetic vector. The effectiveness of the proposed methods is assessed by numerical simulations and experimental tests. The results of the tests are compared with the most recent methods proposed in the literature.

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IMU gyroscopes are a valid alternative to 3D optical motion capture system for angular kinematics analysis in tennis

Proceedings of the Institution of Mechanical Engineers Part P Journal of Sports Engineering and Technology ◽

10.1177/1754337120965444 ◽

2020 ◽

pp. 175433712096544 ◽

Cited By ~ 1

Author(s):

Gabriel Delgado-García ◽

Jos Vanrenterghem ◽

Emilio J Ruiz-Malagón ◽

Pablo Molina-García ◽

Javier Courel-Ibáñez ◽

...

Keyword(s):

Angular Velocity ◽

Motion Capture ◽

Correlation Coefficients ◽

Strong Relationship ◽

System Level ◽

Optical Motion ◽

Measurement Units ◽

The Difference ◽

Optical Motion Capture ◽

Level Of Agreement

Whereas 3D optical motion capture (OMC) systems are considered the gold standard for kinematic assessment in sport science, they present some drawbacks that limit its use in the field. Inertial measurement units (IMUs) incorporating gyroscopes have been considered as a more practical alternative. Thus, the aim of the study was to evaluate the level of agreement for angular velocity between IMU gyroscopes and an OMC system for varying tennis strokes and intensities. In total, 240 signals of angular velocity from different body segments and types of strokes (forehand, backhand and service) were recorded from four players (two competition players and two beginners). The angular velocity of the IMU gyroscopes was compared to the angular velocity from the OMC system. Level of agreement was evaluated by correlation coefficients, magnitudes of errors in absolute and relative values and Bland-Altman plots. Differences between both systems were highly consistent within players’ skill (i.e. along the broad range of velocities) and axes ( x, y, z). Correlations ranged from 0.951 to 0.993, indicating a very strong relationship and concordance. The magnitude of the differences ranged from 4.4 to 35.4 deg·s−1. The difference relative to the maximum angular velocity achieved was less than 5.0%. The study concluded that IMUs and OMC systems showed comparable values. Thus, IMUs seem to be a valid alternative to detect meaningful differences in angular velocity during tennis groundstrokes in field-based experimentation.

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Reliability and Agreement of 3D Trunk and Lower Extremity Movement Analysis by Means of Inertial Sensor Technology for Unipodal and Bipodal Tasks

Sensors ◽

10.3390/s19010141 ◽

2019 ◽

Vol 19 (1) ◽

pp. 141 ◽

Cited By ~ 5

Author(s):

Rob Van der Straaten ◽

Amber K. B. D. Bruijnes ◽

Benedicte Vanwanseele ◽

Ilse Jonkers ◽

Liesbet De Baets ◽

...

Keyword(s):

Lower Limb ◽

Sagittal Plane ◽

Inertial Sensor ◽

Movement Analysis ◽

Sensor Technology ◽

Inertial Measurement ◽

Sit To Stand ◽

Movement Strategies ◽

Measurement Units ◽

Healthy Participants

This study evaluates the reliability and agreement of the 3D range of motion (ROM) of trunk and lower limb joints, measured by inertial measurement units (MVN BIOMECH Awinda, Xsens Technologies), during a single leg squat (SLS) and sit to stand (STS) task. Furthermore, distinction was made between movement phases, to discuss the reliability and agreement for different phases of both movement tasks. Twenty healthy participants were measured on two testing days. On day one, measurements were conducted by two operators to determine the within-session and between-operator reliability and agreement. On day two, measurements were conducted by the same operator, to determine the between-session reliability and agreement. The SLS task had lower within-session reliability and agreement compared with between-session and between-operator reliability and agreement. The reliability and agreement of the hip, knee, and ankle ROM in the sagittal plane were good for both phases of the SLS task. For both phases of STS task, within-session reliability and agreement were good, and between-session and between-operator reliability and agreement were lower in all planes. As both tasks are physically demanding, differences may be explained by inconsistent movement strategies. These results show that inertial sensor systems show promise for use in further research to investigate (mal)adaptive movement strategies.

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FES-Induced Cycling in Complete SCI: A Simpler Control Method Based on Inertial Sensors

Sensors ◽

10.3390/s19194268 ◽

2019 ◽

Vol 19 (19) ◽

pp. 4268

Author(s):

Benoît Sijobert ◽

Ronan Le Guillou ◽

Charles Fattal ◽

Christine Azevedo Coste

Keyword(s):

Electrical Stimulation ◽

Control Method ◽

Inertial Sensors ◽

Inertial Sensor ◽

Setting Time ◽

Reference Information ◽

Novel Approach ◽

Crank Angle ◽

Measurement Units ◽

User Friendly

This article introduces a novel approach for a functional electrical stimulation (FES) controller intended for FES-induced cycling based on inertial measurement units (IMUs). This study aims at simplifying the design of electrical stimulation timing patterns while providing a method that can be adapted to different users and devices. In most of studies and commercial devices, the crank angle is used as an input to trigger stimulation onset. We propose instead to use thigh inclination as the reference information to build stimulation timing patterns. The tilting angles of both thighs are estimated from one inertial sensor located above each knee. An IF–THEN rule algorithm detects, online and automatically, the thigh peak angles in order to start and stop the stimulation of quadriceps muscles, depending on these events. One participant with complete paraplegia was included and was able to propel a recumbent trike using the proposed approach after a very short setting time. This new modality opens the way for a simpler and user-friendly method to automatically design FES-induced cycling stimulation patterns, adapted to clinical use, for multiple bike geometries and user morphologies.

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Benchmarking the Accuracy of Inertial Measurement Units for Estimating Joint Reactions

Volume 3B: Biomedical and Biotechnology Engineering ◽

10.1115/imece2013-63300 ◽

2013 ◽

Cited By ~ 1

Author(s):

Ryan S. McGinnis ◽

Jessandra Hough ◽

N. C. Perkins

Keyword(s):

Three Dimensional ◽

Correlation Coefficients ◽

Human Motion ◽

Load Cell ◽

Great Promise ◽

Human Motion Analysis ◽

Double Pendulum ◽

Inertial Measurement Units ◽

Inertial Measurement ◽

Measurement Units

Newly developed miniature wireless inertial measurement units (IMUs) hold great promise for measuring and analyzing multibody system dynamics. This relatively inexpensive technology enables non-invasive motion tracking in broad applications, including human motion analysis. The second part of this two-part paper advances the use of an array of IMUs to estimate the joint reactions (forces and moments) in multibody systems via inverse dynamic modeling. In particular, this paper reports a benchmark experiment on a double-pendulum that reveals the accuracy of IMU-informed estimates of joint reactions. The estimated reactions are compared to those measured by high precision miniature (6 dof) load cells. Results from ten trials demonstrate that IMU-informed estimates of the three dimensional reaction forces remain within 5.0% RMS of the load cell measurements and with correlation coefficients greater than 0.95 on average. Similarly, the IMU-informed estimates of the three dimensional reaction moments remain within 5.9% RMS of the load cell measurements and with correlation coefficients greater than 0.88 on average. The sensitivity of these estimates to mass center location is discussed. Looking ahead, this benchmarking study supports the promising and broad use of this technology for estimating joint reactions in human motion applications.

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Estimation of Knee Joint Forces in Sport Movements Using Wearable Sensors and Machine Learning

Sensors ◽

10.3390/s19173690 ◽

2019 ◽

Vol 19 (17) ◽

pp. 3690 ◽

Cited By ~ 22

Author(s):

Bernd J. Stetter ◽

Steffen Ringhof ◽

Frieder C. Krafft ◽

Stefan Sell ◽

Thorsten Stein

Keyword(s):

Knee Joint ◽

Wearable Sensors ◽

Correlation Coefficients ◽

Biomechanical Modelling ◽

Joint Forces ◽

Measurement Units ◽

Artificial Neural Network Ann ◽

The Right ◽

Anterior Posterior ◽

Good Agreement

Knee joint forces (KJF) are biomechanical measures used to infer the load on knee joint structures. The purpose of this study is to develop an artificial neural network (ANN) that estimates KJF during sport movements, based on data obtained by wearable sensors. Thirteen participants were equipped with two inertial measurement units (IMUs) located on the right leg. Participants performed a variety of movements, including linear motions, changes of direction, and jumps. Biomechanical modelling was carried out to determine KJF. An ANN was trained to model the association between the IMU signals and the KJF time series. The ANN-predicted KJF yielded correlation coefficients that ranged from 0.60 to 0.94 (vertical KJF), 0.64 to 0.90 (anterior–posterior KJF) and 0.25 to 0.60 (medial–lateral KJF). The vertical KJF for moderate running showed the highest correlation (0.94 ± 0.33). The summed vertical KJF and peak vertical KJF differed between calculated and predicted KJF across all movements by an average of 5.7% ± 5.9% and 17.0% ± 13.6%, respectively. The vertical and anterior–posterior KJF values showed good agreement between ANN-predicted outcomes and reference KJF across most movements. This study supports the use of wearable sensors in combination with ANN for estimating joint reactions in sports applications.

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Comparing Clothing-Mounted Sensors with Wearable Sensors for Movement Analysis and Activity Classification

Sensors ◽

10.3390/s20010082 ◽

2019 ◽

Vol 20 (1) ◽

pp. 82 ◽

Cited By ~ 1

Author(s):

Udeni Jayasinghe ◽

William S. Harwin ◽

Faustina Hwang

Keyword(s):

Inertial Sensors ◽

Inertial Sensor ◽

Wearable Sensors ◽

Correlation Coefficients ◽

Movement Analysis ◽

Multiple Sensors ◽

Sensor Orientation ◽

Multiple Devices ◽

Good Potential ◽

Sensor Errors

Inertial sensors are a useful instrument for long term monitoring in healthcare. In many cases, inertial sensor devices can be worn as an accessory or integrated into smart textiles. In some situations, it may be beneficial to have data from multiple inertial sensors, rather than relying on a single worn sensor, since this may increase the accuracy of the analysis and better tolerate sensor errors. Integrating multiple sensors into clothing improves the feasibility and practicality of wearing multiple devices every day, in approximately the same location, with less likelihood of incorrect sensor orientation. To facilitate this, the current work investigates the consequences of attaching lightweight sensors to loose clothes. The intention of this paper is to discuss how data from these clothing sensors compare with similarly placed body worn sensors, with additional consideration of the resulting effects on activity recognition. This study compares the similarity between the two signals (body worn and clothing), collected from three different clothing types (slacks, pencil skirt and loose frock), across multiple daily activities (walking, running, sitting, and riding a bus) by calculating correlation coefficients for each sensor pair. Even though the two data streams are clearly different from each other, the results indicate that there is good potential of achieving high classification accuracy when using inertial sensors in clothing.

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Validity of Wearable Sensors at the Shoulder Joint: Combining Wireless Electromyography Sensors and Inertial Measurement Units to Perform Physical Workplace Assessments

Sensors ◽

10.3390/s19081885 ◽

2019 ◽

Vol 19 (8) ◽

pp. 1885 ◽

Cited By ~ 6

Author(s):

Isabelle Poitras ◽

Mathieu Bielmann ◽

Alexandre Campeau-Lecours ◽

Catherine Mercier ◽

Laurent J. Bouyer ◽

...

Keyword(s):

Wearable Sensors ◽

Correlation Coefficients ◽

Emg Activity ◽

Complex Task ◽

Inertial Measurement Units ◽

Simple Task ◽

Inertial Measurement ◽

Work Related ◽

Measurement Units ◽

Shoulder Kinematics

Background: Workplace adaptation is the preferred method of intervention to diminish risk factors associated with the development of work-related shoulder disorders. However, the majority of the workplace assessments performed are subjective (e.g., questionnaires). Quantitative assessments are required to support workplace adaptations. The aims of this study are to assess the concurrent validity of inertial measurement units (IMUs; MVN, Xsens) in comparison to a motion capture system (Vicon) during lifting tasks, and establish the discriminative validity of a wireless electromyography (EMG) system for the evaluation of muscle activity. Methods: Sixteen participants performed 12 simple tasks (shoulder flexion, abduction, scaption) and 16 complex lifting tasks (lifting crates of different weights at different heights). A Delsys Trigno EMG system was used to record anterior and middle deltoids’ EMG activity, while the Xsens and Vicon simultaneously recorded shoulder kinematics. Results: For IMUs, correlation coefficients were high (simple task: >0.968; complex task: >0.84) and RMSEs were low (simple task: <6.72°; complex task: <11.5°). For EMG, a significant effect of weight, height and a weight x height interaction (anterior: p < 0.001; middle: p < 0.03) were observed for RMS EMG activity. Conclusions: These results suggest that wireless EMG and IMUs are valid units that can be used to measure physical demand in workplace assessments.

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Differences in head accelerations and physiological demand between live and simulated professional horse racing

Comparative Exercise Physiology ◽

10.3920/cep190005 ◽

2019 ◽

Vol 15 (4) ◽

pp. 259-268

Author(s):

C. Quintana ◽

B. Grimshaw ◽

H.E. Rockwood ◽

N.J. Heebner ◽

A.K. Johnson ◽

...

Keyword(s):

Rotational Velocity ◽

Linear Acceleration ◽

Inertial Measurement Units ◽

Specific Exercise ◽

Inertial Measurement ◽

Physiological Demand ◽

Alpha Level ◽

Measurement Units ◽

Race Horse ◽

Physiological Demands

The purpose of this study was to determine if there are differences in mechanical and physiological demand between live and simulated racing. Fifteen male professional jockeys (31.8±9.5 years, 160.78±7.62 cm, 51.2±1.5 kg) were instrumented with inertial measurement units (IMUs) placed on their helmets to measure mechanical stress and a heart rate (HR) monitor. Head accelerations and HR were measured during a live race (between 5.5 and 6.5 furlongs) and a simulated race (equivalent of 6.5 furlongs or 1.5 min) on a race horse simulator. Paired t-tests were used to determine if there were differences between the two racing conditions for each dependent variable. Alpha level was set at P<0.05. Average HR and peak HR were significantly higher during live than simulated racing. The peak resultant linear acceleration, the average resultant linear acceleration, and the peak resultant rotational velocity were significantly higher in live racing than simulated racing. There were no significant differences in average resultant rotational velocity. Simulated racing trials had consistently lower values of head accelerations compared to live racing trials. These results may provide justification for the use of a race horse simulator as a tool capable of use in rehabilitating and returning jockeys to ride following injury as the accelerations and velocities measured on simulated racing trials were lower, suggesting a safer sports-specific exercise, while still approaching the physiological demands of live racing.

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Reduced Purposeful Head Movements During Community Ambulation Following Unilateral Vestibular Loss

Neurorehabilitation and Neural Repair ◽

10.1177/1545968318770271 ◽

2018 ◽

Vol 32 (4-5) ◽

pp. 309-316 ◽

Cited By ~ 5

Author(s):

Serene Sulyn Paul ◽

Leland E. Dibble ◽

Raymond G. Walther ◽

Clough Shelton ◽

Richard Klaus Gurgel ◽

...

Keyword(s):

Head Movement ◽

Cross Sectional Study ◽

Head Movements ◽

Healthy Individuals ◽

Cross Sectional ◽

Vestibular Loss ◽

Vestibular Hypofunction ◽

Large Head ◽

Community Ambulation ◽

Measurement Units

Background. Individuals with unilateral vestibular hypofunction (UVH) alter their movement and reduce mobility to try to stabilize their gaze and avoid symptoms of dizziness and vertigo. Objective. To determine if individuals with UVH 6 weeks after surgery demonstrate altered head and trunk kinematics during community ambulation. Methods. A total of 15 vestibular schwannoma patients with documented postoperative unilateral vestibular loss and 9 healthy controls with symmetrical vestibulo-ocular reflexes participated in this cross-sectional study. Head kinematics (head turn frequency, amplitude, and velocity) and head-trunk coordination during community ambulation were obtained from inertial measurement units for all head movements and within specific amplitudes of head movement. Results. Individuals with UVH made smaller (mean 26° [SD = 3°] vs 32° [SD = 6°]), fewer (mean 133 [SD = 59] vs 221 [SD = 64]), and slower (mean 75°/s [SD = 8°/s] vs 103°/s [SD = 23°/s]) head turns than healthy individuals ( P < .05) but did not demonstrate significantly increased head-trunk coupling (mean 38% [SD = 18%] vs 31% [SD = 11%], P = .22). When small (≤45°) and large (>45°) head turns were considered separately, individuals with UVH demonstrated increased head-trunk coupling compared with healthy individuals for large head turns (mean 54% [SD = 23%] vs 33% [SD = 10%], P = .005). Conclusions. This study demonstrated that although walking at an adequate speed, individuals with UVH made fewer, smaller, and slower head movements symmetrically in both directions compared with healthy individuals and did not decouple their head movement relative to their trunk when required to make larger purposeful head turns during community ambulation.

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