Editorial

4 pages, 192 KiB

Open AccessEditorial

Human and Animal Motion Tracking Using Inertial Sensors

by Frédéric Marin

Sensors 2020, 20(21), 6074; https://doi.org/10.3390/s20216074 - 26 Oct 2020

Cited by 12 | Viewed by 2705

Motion is key to health and wellbeing, something we are particularly aware of in times of lockdowns and restrictions on movement. Considering the motion of humans and animals as a biomarker of the performance of the neuro-musculoskeletal system, its analysis covers a large [...] Read more.

Motion is key to health and wellbeing, something we are particularly aware of in times of lockdowns and restrictions on movement. Considering the motion of humans and animals as a biomarker of the performance of the neuro-musculoskeletal system, its analysis covers a large array of research fields, such as sports, equine science and clinical applications, but also innovative methods and workplace analysis. In this Special Issue of Sensors, we focused on human and animal motion-tracking using inertial sensors. Ten research and two review papers, mainly on human movement, but also on the locomotion of the horse, were selected. The selection of articles in this Special Issue aims to display current innovative approaches exploring hardware and software solutions deriving from inertial sensors related to motion capture and analysis. The selected sample shows that the versatility and pervasiveness of inertial sensors has great potential for the years to come, as, for now, limitations and room for improvement still remain. Full article

(This article belongs to the Special Issue Human and Animal Motion Tracking Using Inertial Sensors)

Research

Jump to: Editorial, Review

19 pages, 3254 KiB

Open AccessArticle

Using Magneto-Inertial Measurement Units to Pervasively Measure Hip Joint Motion during Sports

by Rachel E. Horenstein, Yohann R. Goudeau, Cara L. Lewis and Sandra J. Shefelbine

Sensors 2020, 20(17), 4970; https://doi.org/10.3390/s20174970 - 02 Sep 2020

Cited by 7 | Viewed by 3752

Abstract

The use of wireless sensors to measure motion in non-laboratory settings continues to grow in popularity. Thus far, most validated systems have been applied to measurements in controlled settings and/or for prescribed motions. The aim of this study was to characterize adolescent hip [...] Read more.

The use of wireless sensors to measure motion in non-laboratory settings continues to grow in popularity. Thus far, most validated systems have been applied to measurements in controlled settings and/or for prescribed motions. The aim of this study was to characterize adolescent hip joint motion of elite-level athletes (soccer players) during practice and recreationally active peers (controls) in after-school activities using a magneto-inertial measurement unit (MIMU) system. Opal wireless sensors (APDM Inc., Portland OR, USA) were placed at the sacrum and laterally on each thigh (three sensors total). Hip joint motion was characterized by hip acceleration and hip orientation for one hour of activity on a sports field. Our methods and analysis techniques can be applied to other joints and activities. We also provide recommendations in order to guide future work using MIMUs to pervasively assess joint motions of clinical relevance. Full article

(This article belongs to the Special Issue Human and Animal Motion Tracking Using Inertial Sensors)

► Show Figures

Figure 1

22 pages, 3024 KiB

Open AccessArticle

Classification of Alpine Skiing Styles Using GNSS and Inertial Measurement Units

by Christina Neuwirth, Cory Snyder, Wolfgang Kremser, Richard Brunauer, Helmut Holzer and Thomas Stöggl

Sensors 2020, 20(15), 4232; https://doi.org/10.3390/s20154232 - 29 Jul 2020

Cited by 19 | Viewed by 3557

Abstract

In alpine skiing, four commonly used turning styles are snowplow, snowplow-steering, drifting and carving. They differ significantly in speed, directional control and difficulty to execute. While they are visually distinguishable, data-driven classification is underexplored. The aim of this work is to classify alpine [...] Read more.

In alpine skiing, four commonly used turning styles are snowplow, snowplow-steering, drifting and carving. They differ significantly in speed, directional control and difficulty to execute. While they are visually distinguishable, data-driven classification is underexplored. The aim of this work is to classify alpine skiing styles based on a global navigation satellite system (GNSS) and inertial measurement units (IMU). Data of 2000 turns of 20 advanced or expert skiers were collected with two IMU sensors on the upper cuff of each ski boot and a mobile phone with GNSS. After feature extraction and feature selection, turn style classification was applied separately for parallel (drifted or carved) and non-parallel (snowplow or snowplow-steering) turns. The most important features for style classification were identified via recursive feature elimination. Three different classification methods were then tested and compared: Decision trees, random forests and gradient boosted decision trees. Classification accuracies were lowest for the decision tree and similar for the random forests and gradient boosted classification trees, which both achieved accuracies of more than 93% in the parallel classification task and 88% in the non-parallel case. While the accuracy might be improved by considering slope and weather conditions, these first results suggest that IMU data can classify alpine skiing styles reasonably well. Full article

(This article belongs to the Special Issue Human and Animal Motion Tracking Using Inertial Sensors)

► Show Figures

Figure 1

17 pages, 1394 KiB

Open AccessArticle

The Influence of Proprioceptive Training with the Use of Virtual Reality on Postural Stability of Workers Working at Height

by Magdalena Cyma-Wejchenig, Jacek Tarnas, Katarzyna Marciniak and Rafał Stemplewski

Sensors 2020, 20(13), 3731; https://doi.org/10.3390/s20133731 - 03 Jul 2020

Cited by 20 | Viewed by 4187

Abstract

The aim of the study was to assess the impact of proprioceptive training with the use of virtual reality (VR) on the level of postural stability of high–altitude workers. Twenty-one men working at height were randomly assigned to the experimental group (EG) with [...] Read more.

The aim of the study was to assess the impact of proprioceptive training with the use of virtual reality (VR) on the level of postural stability of high–altitude workers. Twenty-one men working at height were randomly assigned to the experimental group (EG) with training (n = 10) and control group (CG) without training (n = 11). Path length of the displacement of the center of pressure (COP) signal and its components in the anteroposterior and medial–lateral directions were measured with use of an AccuGaitTM force plate before and after intervention (6 weeks, 2 sessions × 30 min a week). Tests were performed at two different platform heights, with or without eyes open and with or without a dual task. Two–way ANOVA revealed statistically significant interaction effects for low–high threat, eyes open-eyes closed, and single task-dual task. Post-training values of average COP length were significantly lower in the EG than before training for all analyzed parameters. Based on these results, it can be concluded that the use of proprioceptive training with use of VR can support, or even replace, traditional methods of balance training. Full article

(This article belongs to the Special Issue Human and Animal Motion Tracking Using Inertial Sensors)

► Show Figures

Figure 1

31 pages, 7708 KiB

Open AccessArticle

Robust Plug-and-Play Joint Axis Estimation Using Inertial Sensors

by Fredrik Olsson, Manon Kok, Thomas Seel and Kjartan Halvorsen

Sensors 2020, 20(12), 3534; https://doi.org/10.3390/s20123534 - 22 Jun 2020

Cited by 20 | Viewed by 3653

Abstract

Inertial motion capture relies on accurate sensor-to-segment calibration. When two segments are connected by a hinge joint, for example in human knee or finger joints as well as in many robotic limbs, then the joint axis vector must be identified in the intrinsic [...] Read more.

Inertial motion capture relies on accurate sensor-to-segment calibration. When two segments are connected by a hinge joint, for example in human knee or finger joints as well as in many robotic limbs, then the joint axis vector must be identified in the intrinsic sensor coordinate systems. Methods for estimating the joint axis using accelerations and angular rates of arbitrary motion have been proposed, but the user must perform sufficiently informative motion in a predefined initial time window to accomplish complete identifiability. Another drawback of state of the art methods is that the user has no way of knowing if the calibration was successful or not. To achieve plug-and-play calibration, it is therefore important that 1) sufficiently informative data can be extracted even if large portions of the data set consist of non-informative motions, and 2) the user knows when the calibration has reached a sufficient level of accuracy. In the current paper, we propose a novel method that achieves both of these goals. The method combines acceleration- and angular rate information and finds a globally optimal estimate of the joint axis. Methods for sample selection, that overcome the limitation of a dedicated initial calibration time window, are proposed. The sample selection allows estimation to be performed using only a small subset of samples from a larger data set as it deselects non-informative and redundant measurements. Finally, an uncertainty quantification method that assures validity of the estimated joint axis parameters, is proposed. Experimental validation of the method is provided using a mechanical joint performing a large range of motions. Angular errors in the order of

2^{\circ}

were achieved using 125–1000 selected samples. The proposed method is the first truly plug-and-play method that overcome the need for a specific calibration phase and, regardless of the user’s motions, it provides an accurate estimate of the joint axis as soon as possible. Full article

(This article belongs to the Special Issue Human and Animal Motion Tracking Using Inertial Sensors)

► Show Figures

Figure 1

14 pages, 2667 KiB

Open AccessArticle

Estimating Human Wrist Stiffness during a Tooling Task

by Gia-Hoang Phan, Clint Hansen, Paolo Tommasino, Aamani Budhota, Dhanya Menoth Mohan, Asif Hussain, Etienne Burdet and Domenico Campolo

Sensors 2020, 20(11), 3260; https://doi.org/10.3390/s20113260 - 08 Jun 2020

Cited by 8 | Viewed by 3036

Abstract

In this work, we propose a practical approach to estimate human joint stiffness during tooling tasks for the purpose of programming a robot by demonstration. More specifically, we estimate the stiffness along the wrist radial-ulnar deviation while a human operator performs flexion-extension movements [...] Read more.

In this work, we propose a practical approach to estimate human joint stiffness during tooling tasks for the purpose of programming a robot by demonstration. More specifically, we estimate the stiffness along the wrist radial-ulnar deviation while a human operator performs flexion-extension movements during a polishing task. The joint stiffness information allows to transfer skills from expert human operators to industrial robots. A typical hand-held, abrasive tool used by humans during finishing tasks was instrumented at the handle (through which both robots and humans are attached to the tool) to assess the 3D force/torque interactions between operator and tool during finishing task, as well as the 3D kinematics of the tool itself. Building upon stochastic methods for human arm impedance estimation, the novelty of our approach is that we rely on the natural variability taking place during the multi-passes task itself to estimate (neuro-)mechanical impedance during motion. Our apparatus (hand-held, finishing tool instrumented with motion capture and multi-axis force/torque sensors) and algorithms (for filtering and impedance estimation) were first tested on an impedance-controlled industrial robot carrying out the finishing task of interest, where the impedance could be pre-programmed. We were able to accurately estimate impedance in this case. The same apparatus and algorithms were then applied to the same task performed by a human operators. The stiffness values of the human operator, at different force level, correlated positively with the muscular activity, measured during the same task. Full article

(This article belongs to the Special Issue Human and Animal Motion Tracking Using Inertial Sensors)

► Show Figures

Figure 1

14 pages, 2597 KiB

Open AccessArticle

Comparison of Trotting Stance Detection Methods from an Inertial Measurement Unit Mounted on the Horse’s Limb

by Marie Sapone, Pauline Martin, Khalil Ben Mansour, Henry Château and Frédéric Marin

Sensors 2020, 20(10), 2983; https://doi.org/10.3390/s20102983 - 25 May 2020

Cited by 14 | Viewed by 3340

Abstract

The development of on-board sensors, such as inertial measurement units (IMU), has made it possible to develop new methods for analyzing horse locomotion to detect lameness. The detection of spatiotemporal events is one of the keystones in the analysis of horse locomotion. This [...] Read more.

The development of on-board sensors, such as inertial measurement units (IMU), has made it possible to develop new methods for analyzing horse locomotion to detect lameness. The detection of spatiotemporal events is one of the keystones in the analysis of horse locomotion. This study assesses the performance of four methods for detecting Foot on and Foot off events. They were developed from an IMU positioned on the canon bone of eight horses during trotting recording on a treadmill and compared to a standard gold method based on motion capture. These methods are based on accelerometer and gyroscope data and use either thresholding or wavelets to detect stride events. The two methods developed from gyroscopic data showed more precision than those developed from accelerometric data with a bias less than 0.6% of stride duration for Foot on and 0.1% of stride duration for Foot off. The gyroscope is less impacted by the different patterns of strides, specific to each horse. To conclude, methods using the gyroscope present the potential of further developments to investigate the effects of different gait paces and ground types in the analysis of horse locomotion. Full article

(This article belongs to the Special Issue Human and Animal Motion Tracking Using Inertial Sensors)

► Show Figures

Figure 1

17 pages, 3838 KiB

Open AccessArticle

Canoeing Motion Tracking and Analysis via Multi-Sensors Fusion

by Long Liu, Sen Qiu, ZheLong Wang, Jie Li and JiaXin Wang

Sensors 2020, 20(7), 2110; https://doi.org/10.3390/s20072110 - 08 Apr 2020

Cited by 21 | Viewed by 4157

Abstract

Coaches and athletes are constantly seeking novel training methodologies in an attempt to improve athletic performance. This paper proposes a method of rowing sport capture and analysis based on Inertial Measurement Units (IMUs). A canoeist’s motion was collected by multiple miniature inertial sensor [...] Read more.

Coaches and athletes are constantly seeking novel training methodologies in an attempt to improve athletic performance. This paper proposes a method of rowing sport capture and analysis based on Inertial Measurement Units (IMUs). A canoeist’s motion was collected by multiple miniature inertial sensor nodes. The gradient descent method was used to fuse data and obtain the canoeist’s attitude information after sensor calibration, and then the motions of canoeist’s actions were reconstructed. Stroke quality was performed based on the estimated joint angles. Machine learning algorithm was used as the classification method to divide the stroke cycle into different phases, including propulsion-phase and recovery-phase, a quantitative kinematic analysis was carried out. Experiments conducted in this paper demonstrated that our method possesses the capacity to reveal the similarities and differences between novice and coach, the whole process of canoeist’s motions can be analyzed with satisfactory accuracy validated by videography method. It can provide quantitative data for coaches or athletes, which can be used to improve the skills of rowers. Full article

(This article belongs to the Special Issue Human and Animal Motion Tracking Using Inertial Sensors)

► Show Figures

Figure 1

19 pages, 6474 KiB

Open AccessArticle

Racquet Sports Recognition Using a Hybrid Clustering Model Learned from Integrated Wearable Sensor

by Kun Xia, Hanyu Wang, Menghan Xu, Zheng Li, Sheng He and Yusong Tang

Sensors 2020, 20(6), 1638; https://doi.org/10.3390/s20061638 - 15 Mar 2020

Cited by 24 | Viewed by 3938

Abstract

Racquet sports can provide positive benefits for human healthcare. A reliable detection device that can effectively distinguish movement with similar sub-features is therefore needed. In this paper, a racquet sports recognition wristband system and a multilayer hybrid clustering model are proposed to achieve [...] Read more.

Racquet sports can provide positive benefits for human healthcare. A reliable detection device that can effectively distinguish movement with similar sub-features is therefore needed. In this paper, a racquet sports recognition wristband system and a multilayer hybrid clustering model are proposed to achieve reliable activity recognition and perform number counting. Additionally, a Bluetooth mesh network enables communication between a phone and wristband, and sets-up the connection between multiple devices. This allows users to track their exercise through the phone and share information with other players and referees. Considering the complexity of the classification algorithm and the user-friendliness of the measurement system, the improved multi-layer hybrid clustering model applies three-level K-means clustering to optimize feature extraction and segmentation and then uses the density-based spatial clustering of applications with noise (DBSCAN) algorithm to determine the feature center of different movements. The model can identify unlabeled and noisy data without data calibration and is suitable for smartwatches to recognize multiple racquet sports. The proposed system shows better recognition results and is verified in practical experiments. Full article

(This article belongs to the Special Issue Human and Animal Motion Tracking Using Inertial Sensors)

► Show Figures

Figure 1

27 pages, 1994 KiB

Open AccessArticle

Walking Recognition in Mobile Devices

by Fernando E. Casado, Germán Rodríguez, Roberto Iglesias, Carlos V. Regueiro, Senén Barro and Adrián Canedo-Rodríguez

Sensors 2020, 20(4), 1189; https://doi.org/10.3390/s20041189 - 21 Feb 2020

Cited by 11 | Viewed by 4515

Abstract

Presently, smartphones are used more and more for purposes that have nothing to do with phone calls or simple data transfers. One example is the recognition of human activity, which is relevant information for many applications in the domains of medical diagnosis, elderly [...] Read more.

Presently, smartphones are used more and more for purposes that have nothing to do with phone calls or simple data transfers. One example is the recognition of human activity, which is relevant information for many applications in the domains of medical diagnosis, elderly assistance, indoor localization, and navigation. The information captured by the inertial sensors of the phone (accelerometer, gyroscope, and magnetometer) can be analyzed to determine the activity performed by the person who is carrying the device, in particular in the activity of walking. Nevertheless, the development of a standalone application able to detect the walking activity starting only from the data provided by these inertial sensors is a complex task. This complexity lies in the hardware disparity, noise on data, and mostly the many movements that the smartphone can experience and which have nothing to do with the physical displacement of the owner. In this work, we explore and compare several approaches for identifying the walking activity. We categorize them into two main groups: the first one uses features extracted from the inertial data, whereas the second one analyzes the characteristic shape of the time series made up of the sensors readings. Due to the lack of public datasets of inertial data from smartphones for the recognition of human activity under no constraints, we collected data from 77 different people who were not connected to this research. Using this dataset, which we published online, we performed an extensive experimental validation and comparison of our proposals. Full article

(This article belongs to the Special Issue Human and Animal Motion Tracking Using Inertial Sensors)

► Show Figures

Figure 1

12 pages, 1197 KiB

Open AccessArticle

A Method to Estimate Horse Speed per Stride from One IMU with a Machine Learning Method

by Amandine Schmutz, Laurence Chèze, Julien Jacques and Pauline Martin

Sensors 2020, 20(2), 518; https://doi.org/10.3390/s20020518 - 17 Jan 2020

Cited by 12 | Viewed by 4595

Abstract

With the emergence of numerical sensors in sports, there is an increasing need for tools and methods to compute objective motion parameters with great accuracy. In particular, inertial measurement units are increasingly used in the clinical domain or the sports one to estimate [...] Read more.

With the emergence of numerical sensors in sports, there is an increasing need for tools and methods to compute objective motion parameters with great accuracy. In particular, inertial measurement units are increasingly used in the clinical domain or the sports one to estimate spatiotemporal parameters. The purpose of the present study was to develop a model that can be included in a smart device in order to estimate the horse speed per stride from accelerometric and gyroscopic data without the use of a global positioning system, enabling the use of such a tool in both indoor and outdoor conditions. The accuracy of two speed calculation methods was compared: one signal based and one machine learning model. Those two methods allowed the calculation of speed from accelerometric and gyroscopic data without any other external input. For this purpose, data were collected under various speeds on straight lines and curved paths. Two reference systems were used to measure the speed in order to have a reference speed value to compare each tested model and estimate their accuracy. Those models were compared according to three different criteria: the percentage of error above 0.6 m/s, the RMSE, and the Bland and Altman limit of agreement. The machine learning method outperformed its competitor by giving the lowest value for all three criteria. The main contribution of this work is that it is the first method that gives an accurate speed per stride for horses without being coupled with a global positioning system or a magnetometer. No similar study performed on horses exists to compare our work with, so the presented model is compared to existing models for human walking. Moreover, this tool can be extended to other equestrian sports, as well as bipedal locomotion as long as consistent data are provided to train the machine learning model. The machine learning model’s accurate results can be explained by the large database built to train the model and the innovative way of slicing stride data before using them as an input for the model. Full article

(This article belongs to the Special Issue Human and Animal Motion Tracking Using Inertial Sensors)

► Show Figures

Figure 1

Review

Jump to: Editorial, Research

22 pages, 836 KiB

Open AccessReview

Sensor-to-Segment Calibration Methodologies for Lower-Body Kinematic Analysis with Inertial Sensors: A Systematic Review

by Léonie Pacher, Christian Chatellier, Rodolphe Vauzelle and Laetitia Fradet

Sensors 2020, 20(11), 3322; https://doi.org/10.3390/s20113322 - 11 Jun 2020

Cited by 44 | Viewed by 5496

Abstract

Kinematic analysis is indispensable to understanding and characterizing human locomotion. Thanks to the development of inertial sensors based on microelectronics systems, human kinematic analysis in an ecological environment is made possible. An important issue in human kinematic analyses with inertial sensors is the [...] Read more.

Kinematic analysis is indispensable to understanding and characterizing human locomotion. Thanks to the development of inertial sensors based on microelectronics systems, human kinematic analysis in an ecological environment is made possible. An important issue in human kinematic analyses with inertial sensors is the necessity of defining the orientation of the inertial sensor coordinate system relative to its underlying segment coordinate system, which is referred to sensor-to-segment calibration. Over the last decade, we have seen an increase of proposals for this purpose. The aim of this review is to highlight the different proposals made for lower-body segments. Three different databases were screened: PubMed, Science Direct and IEEE Xplore. One reviewer performed the selection of the different studies and data extraction. Fifty-five studies were included. Four different types of calibration method could be identified in the articles: the manual, static, functional, and anatomical methods. The mathematical approach to obtain the segment axis and the calibration evaluation were extracted from the selected articles. Given the number of propositions and the diversity of references used to evaluate the methods, it is difficult today to form a conclusion about the most suitable. To conclude, comparative studies are required to validate calibration methods in different circumstances. Full article

(This article belongs to the Special Issue Human and Animal Motion Tracking Using Inertial Sensors)

► Show Figures

Figure 1

20 pages, 1447 KiB

Open AccessReview

Wearable Inertial Sensors to Assess Gait during the 6-Minute Walk Test: A Systematic Review

by Fabio Alexander Storm, Ambra Cesareo, Gianluigi Reni and Emilia Biffi

Sensors 2020, 20(9), 2660; https://doi.org/10.3390/s20092660 - 06 May 2020

Cited by 43 | Viewed by 4711

Abstract

Wearable sensors are becoming increasingly popular for complementing classical clinical assessments of gait deficits. The aim of this review is to examine the existing knowledge by systematically reviewing a large number of papers focusing on the use of wearable inertial sensors for the [...] Read more.

Wearable sensors are becoming increasingly popular for complementing classical clinical assessments of gait deficits. The aim of this review is to examine the existing knowledge by systematically reviewing a large number of papers focusing on the use of wearable inertial sensors for the assessment of gait during the 6-minute walk test (6MWT), a widely recognized, simple, non-invasive, low-cost and reproducible exercise test. After a systematic search on PubMed and Scopus databases, two raters evaluated the quality of 28 full-text articles. Then, the available knowledge was summarized regarding study design, subjects enrolled (number of patients and pathological condition, if any, age, male/female ratio), sensor characteristics (type, number, sampling frequency, range) and body placement, 6MWT protocol and extracted parameters. Results were critically discussed to suggest future directions for the use of inertial sensor devices in the clinics. Full article

(This article belongs to the Special Issue Human and Animal Motion Tracking Using Inertial Sensors)

► Show Figures

Figure 1

Journal Menu

Journal Browser

Human and Animal Motion Tracking Using Inertial Sensors

Share This Special Issue

Special Issue Editor

Special Issue Information

Published Papers (13 papers)

Editorial

Research

Review

Further Information

Guidelines

MDPI Initiatives

Follow MDPI