Marker-less motion capture for biomechanical analysis using the Kinect sensor BACHERLOR'S THESIS Escola Tècnica Superior d'Enginyeria Industrial de Barcelona (original) (raw)

Accuracy of joint angles tracking using markerless motion system I

2014

Human motion analysis is a widely accepted diagnostic tool in the field of medicine, sports, and biomechanics. Clinicians and Rehabilitators use this technology to identify the fundamentals of human gait and posture deviations. Various motion analysis methods exist, some track body motion using markers placed on the body while others track motion without using markers. In this paper, the performance of Microsoft Kinect as a marker-less system to track Sit-to-Stand movement is compared with the performance of a Myomotion system that uses inertial sensors to track the same motion. Four healthy adult persons performed sit to stand movement and Joint angles of hips, knees and ankles were collected at real time using Kinect and Inertial sensors. A correlation analysis was performed on the angles calculated from the data collected using the Kinect and Inertial sensors. Results showed a high correlation for kinematics of knee and lower values for hips and ankles. RMSE (Root mean square err...

Acquiring Kinematics of Lower extremity with Kinect

European Journal of Science and Technology, 2022

Gait analysis is used in monitoring the procedures of treatment and determining many illnesses notably musculoskeletal system disorders. Gait analysis has been carried out with divergent methods for a long time. In this study, kinematic parameters of lower human extremities are determined using Kinect, a camera called Time of Flight that is usually used in the entertainment sector. Kinect is recommended as a low-cost solution for existing gait analysis systems. Kinematic parameters that are used to analyze walking are found by filtering RGB images of colored markers that are attached to joints. 3D world coordinates of the marker centers were determined and labeled by mapping the depth information, which is obtained from Kinect, on RGB images. We used the Kalman filter to estimate the coordinates of markers when the coordinates cannot be accurately determined because of motion blurring. 15 kinematic parameters for each joint are extracted from the coordinates of these markers.

Automatic 2D Motion Capture System for Joint Angle Measurement

Advances in Computational Intelligence, 2017

Joints angles are some of the most common measurements for the evaluation of lower limb injury risk, specially of lower limb joints. The 2D projections of these angles, as the Frontal Plane Projection Angle (FPPA), are widely used as an estimation of the angle value. Traditional procedures to measure 2D angles imply huge time investments, primarily when evaluating multiple subjects. This work presents a novel 2D video analysis system directed to capture the joint angles in a cost-and-timeeffective way. It employs Kinect V2 depth sensor to track retro-reflective markers attached to the patient's joints to provide an automatic estimation of the desired angles. The information registered by the sensor is processed and managed by a computer application that expedites the analysis of the results. The reliability of the system has been studied against traditional procedures obtaining excellent results. This system is aimed to be the starting point of an autonomous injury prediction system based on machine learning techniques.

Upper Limb Joints and Motions Sampling System Using Kinect Camera

2018

The needs of research on human posture and its joint-motion relationships are important. Providing a real-time postural measurement tool has attracted the attention of many human postural-related researchers. This study has developed and performed a validation analysis on a new innovative system for sampling and finding the angles of motions of each posture with its related joints using Kinect camera. The validation investigated the static and dynamic accuracy analyses by comparing to a Jamar goniometer and ErgoFellow system. The results showed that Mean Absolute Errors of Kinect in static and dynamic motions are 15.12% and 45.33% respectively. It is concluded that the postural measurement system developed by this study requires further improvements.

Development of a Motion Capture System Using Kinect

Jurnal Teknologi, 2015

Microsoft Kinect has been identified as a potential alternative tool in the field of motion capture due to its simplicity and low cost. To date, the application and potential of Microsoft Kinect has been vigorously explored especially for entertainment and gaming purposes. However, its motion capture capability in terms of repeatability and reproducibility is still not well addressed. Therefore, this study aims to explore and develop a motion capture system using Microsoft Kinect; focusing on developing the interface, motion capture protocol as well as measurement analysis. The work is divided into several stages which include installation (Microsoft Kinect and MATLAB); parameters and experimental setup, interface development; protocols development; motion capture; data tracking and measurement analysis. The results are promising, where the variances are found to be less than 1% for both repeatability and reproducibility analysis. This proves that the current study is significant an...

Feasibility Study of Markerless Gait Tracking Using Kinect

2014

Gait analysis is a complex process since it involves tracking motion with high degrees of freedom. It has seen a lot of development in recent years with approaches changing from Markerbased to Markerless systems. This paper presents a new approach for gait analysis that is based on Markerless human motion capture using Microsoft’s popular gaming console Kinect XBOX. For this study, the RGB camera mode output of the Kinect system was used as Markerbased system. The skeleton mode output of the Kinect system was used as Markerless system. The system introduced in this paper tracked the human motion in a real time environment using foreground segmentation and computer vision algorithms developed for this purpose. The study shows that Kinect can be used both as Markerbased and Markerless systems for tracking human motion. The degree angles formed from the motion of 5 joints namely shoulder, elbow, hip, knee and ankle were calculated. The RGB camera of Kinect was used to track marks place...

Performance of Dual Depth Camera Motion Capture System for Athletes’ Biomechanics Analysis

MATEC Web of Conferences, 2017

Motion capture system has recently being brought to light and drawn much attention in many fields of research, especially in biomechanics. Marker-based motion capture systems have been used as the main tool in capturing motion for years. Marker-based motion capture systems are very pricey, lab-based and beyond reach of many researchers, hence it cannot be applied to ubiquitous applications. The game however has changed with the introduction of depth camera technology, a markerless yet affordable motion capture system. By means of this system, motion capture has been promoted as more portable application and does not require substantial time in setting up the system. Limitation in terms of nodal coverage of single depth camera has widely accepted but the performance of dual depth camera system is still doubtful since it is expected to improve the coverage issue but at the same time has bigger issues on data merging and accuracy. This work appraises the accuracy performance of dual depth camera motion capture system specifically for athletes' running biomechanics analysis. Kinect sensors were selected to capture motions of an athlete simultaneously in three-dimension, and fused the recorded data into an analysable data. Running was chosen as the biomechanics motion and interpreted in the form of angle-time, angleangle and continuous relative phase plot. The linear and angular kinematics were analysed and represented graphically. Quantitative interpretations of the result allowed the deep insight of the movement and joint coordination of the athlete. The result showed that the root-mean-square error of the Kinect sensor measurement to exact measurement data and rigid transformation were 0.0045 and 0.0077291 respectively. The velocity and acceleration of the subject were determined to be 3.3479 ms-1 and −4.1444 ms-2. The result showed that the dual Kinect camera motion capture system was feasible to perform athletes' biomechanics analysis.

Measuring human movement for biomechanical applications using markerless motion capture

Three-Dimensional Image Capture and Applications VII, 2006

Modern biomechanical and clinical applications require the accurate capture of normal and pathological human movement without the artifacts associated with standard marker-based motion capture techniques such as soft tissue artifacts and the risk of artificial stimulus of taped-on or strapped-on markers. In this study, the need for new markerless human motion capture methods is discussed in view of biomechanical applications. Three different approaches for estimating human movement from multiple image sequences were explored. The first two approaches tracked a 3D articulated model in 3D representations constructed from the image sequences, while the third approach tracked a 3D articulated model in multiple 2D image planes. The three methods are systematically evaluated and results for real data are presented. The role of choosing appropriate technical equipment and algorithms for accurate markerless motion capture is critical. The implementation of this new methodology offers the promise for simple, time-efficient, and potentially more meaningful assessments of human movement in research and clinical practice.

MICROSOFT KINECT™ ACCURACY IN THE KINEMATIC ANALYSIS OF THE HUMAN MOVEMENT Acurácia do Microsoft Kinect® na análise cinemática do movimento humano Autor de correspondência

The lack of low cost devices apt to collaborate both researches and clinical intervention s quality for health promotion is quite significant, peculiarly in developing countries. The objective of this study consisted in calculating the accuracy of the hardware Kinect™ by Microsoft™. Methods: anthropometric data were collected from a subject in orthostatic position, at four different distances from the optical axes of the hardware, on X, Y and Z. The normality and the variances homogeinity of the data were stated through Kolmogorov-Smirnov and Barlett’s tests, in this order. It has been adopted a significance P < 0.05 for all the statistical tests, and the size effect for all of the spatial coordinates (in the four different placements) exceeded 0.80. Results: the relative error presented no significant differences in all of those distances in the three spatial axels and the accuracy averaged 0.047m; such result allows to conclude that the hardware presents satisfactory both scientific and clinical applicability, embracing potentially human movement investigations and interventions, as well as orthopedics, physiotherapy, physical education, and sports among others.

Flexible software for the elimination of the markers used in the analysis of human posture through kinect®sensor

Archives of Physiotherapy and Global Researches, 2016

From a cibernetic approach, the body system can be defined like a net of structural and functional related subsystems with motor equifinality inside the concept of balance, energetic economy and comfort: therefore the ideal posture is the one that allows the maximum effectiveness of motor gesture, in absence of pain with the maximum energetic economy. The present study research is based on the necessity to individuate a real objective evaluation system of the postural parameters, inexpensive and of simple use compared to the evaluation instruments in use already scientifically validated. The instrument used in this study is the Microsoft Kinect®, gaming platform combined with the Xbox console. Created by Microsoft in the field of play, the Microsoft Kinect® for years has entertained millions of consumers through the Motion Capture System, the recording of movement through cameras and instant or deferred replay. The primary aim of this randomized controlled single-blind research is the demonstration that, despite being commonly defined objective the evaluation systems that utilize markers, is essential to look for an alternative evaluation method to minimize the systematic human error. The results demonstrate the real validity of Kinect®, and have verified the reliability of the data obtained from the assessment, showing the scientific reliability of this innovative objective evaluation method in rehabilitation-clinical field.