scholarly journals KINEMATIC DIFFERENCES IN LEFT-RIGHT SIDE IN BLOCKING AMONG COLLEGE WOMEN'S VOLLEYBALL PLAYERS IN JAPAN

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Koki Numata ◽  
Yoshie Motoshima ◽  
Koji Hamada ◽  
Misato Sakanaka ◽  
Shunsuke Murakami ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Block System ◽  
Left Handed ◽  
Motion Time ◽  
Volleyball Players ◽  
Optical Motion ◽  
The Difference ◽  
Optical Motion Capture ◽  
Women's Volleyball ◽  
Better Than

In recent years, the attacking tactics of top-level teams have been dominated by a combination of four attackers. The basic approach to defending against this move is to block in the direction of the toss (Read Block System). This study compares and examines the difference between the left and right sides of the crossover step of women's volleyball players using the read block system. Fifteen Japanese college women's volleyball players (age: 20.1±1.1 years, height: 169.3±5.5 cm) were eligible for the study. A time-synchronized 16 camera Mac3D optical motion capture systems (Motion Analysis Co.) and 10 force plates (Tec Gihan Co.) were used to determine three dimensional (3-D) coordinates of 38 retroreflective markers. The players were told that the toss from the setter would go up randomly in one of the left or right direction, and they were asked to block in response to the toss from the centre of the net. The results showed that the performance of the jump height (p = 0.04, d =0.50), maximum block reach (p = 0.01, d =0.51), and motion time (p =0.02, d =0.75) was better than the left, and the effect size was large. Since most of the subjects in this study were right-handed (two of the Opposites were left-handed), it is assumed that they tended to perform better on the left side, which is a block stepping similar to spike stepping. However, some players may not use the spiking hand, so individualized instruction is required.

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

2020 ◽  
pp. 175433712096544 ◽  
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.

A Dynamic Position Measurement Method for Destructive Process of Structures Using Image Processing

2004 ◽  
Author(s):  
Hiroshi Nishizawa ◽  
Satoshi Fujita ◽  
Osamu Furuya
Keyword(s):  
Image Processing ◽  
High Precision ◽  
High Speed ◽  
Spherical Surface ◽  
Three Dimensional ◽  
Measuring System ◽  
Position Measurement ◽  
Surface Emission ◽  
Optical Motion ◽  
Optical Motion Capture

In order to clarify the destruction mechanism of large structures in large seismic movements, a non-contacting displacement measurement system with a three-dimensional dynamic position with high precision is required. We have developed a three-dimensional measuring system with image processing using optical motion capture technology. This system consists of light emitting markers installed on the object structure and plural high speed cameras which obtain images of markers’ movement simultaneously, to measure the dynamic position of the three dimensional spatial coordinates of the markers. In order to measure the dynamic position with high precision, we have ever developed sub-pixel processing method which is able to measure very small displacements of the markers by analyzing the luminance distribution. Moreover, we have developed a new marker of spherical surface emission type which formed the luminance profile to improve furthermore the accuracy in rotational movement. Shaking tests were carried out with this measuring system and the results indicated that this system using new markers had sufficient accuracy within errors of a few millimeters in the structure of a 4 meter cube. Consequently, we have acquired the potential to apply to the measurement to the 3-D Full Scale Earthquake Testing Facility (E-Defense).

scholarly journals Comparison of modelling and tracking methods for analysing elbow and forearm kinematics

2019 ◽  
Vol 233 (11) ◽  
pp. 1113-1121 ◽  
Author(s):  
Wei Wang ◽  
Dongmei Wang ◽  
Mariska Wesseling ◽  
Bin Xue ◽  
Feiyue Li
Keyword(s):  
Three Dimensional ◽  
Optimal Estimation ◽  
Elbow Flexion ◽  
Coordinate Systems ◽  
Kinematic Data ◽  
Measurement Protocol ◽  
Flexion Extension ◽  
Good Consistency ◽  
Optical Motion ◽  
Optical Motion Capture

This study aimed to find an optimal measurement protocol of elbow and forearm kinematics using different modelling and tracking methods. Kinematic data of elbow flexion/extension and forearm pronation/supination was acquired using optical motion capture from 12 healthy male volunteers. Segment coordinate systems for humerus, forearm, radius, ulna, and hand were defined. Different tracking methods, using anatomical markers or rigid or point maker clusters, were used to compute the three-dimensional rotations. Marker placement errors were assessed to evaluate the rigid body assumption. Multiple comparisons demonstrated statistical differences between tracking methods: compared to using only anatomical markers, tracking using clusters reduced the estimated range of pronation/supination by 14.9%–43.2%, while it estimated increased flexion/extension by 5.3%–9.1%. The study suggests using only anatomical markers exerts the optimal estimation of elbow and forearm kinematics. Modelling using the coordinate systems of the humerus and forearm and of the humerus and ulna, respectively, demonstrated good consistency with literature and are correspondingly regarded as the most appropriate approach for measuring pronation/supination and flexion/extension. The results are valuable in establishing a measurement protocol for analysing elbow and forearm kinematics, avoiding confusions and misinterpretations in communicating results from different methodologies.

scholarly journals An Automated Three-Dimensional Bone Pose Tracking Method Using Clinical Interleaved Biplane Fluoroscopy Systems: Application to the Knee

2020 ◽  
Vol 10 (23) ◽  
pp. 8426
Author(s):  
Cheng-Chung Lin ◽  
Tung-Wu Lu ◽  
Jia-Da Li ◽  
Mei-Ying Kuo ◽  
Chien-Chun Kuo ◽  
...  
Keyword(s):  
Imaging System ◽  
Three Dimensional ◽  
Pose Tracking ◽  
Model Based ◽  
X Ray Imaging ◽  
Custom Made ◽  
Optical Motion ◽  
Optical Motion Capture ◽  
Tibiofemoral Kinematics ◽  
Biplane Fluoroscopy

Model-based tracking of the movement of the tibiofemoral joint via a biplane X-ray imaging system has been commonly used to reproduce its accurate, three-dimensional kinematics. To accommodate the approaches to existing clinical asynchronous biplane fluoroscopy systems and achieve comparable accuracy, this study proposed an automated model-based interleaved biplane fluoroscopy image tracking scheme (MIBFT) by incorporating information of adjacent image frames. The MIBFT was evaluated with a cadaveric study conducted on a knee specimen. The MIBFT reproduced skeletal poses and tibiofemoral kinematics that were in good agreement with the standard reference kinematics provided by an optical motion capture system, in which the root-mean-squared (Rms) errors of the skeletal pose parameters ranged from 0.11 to 0.35 mm in translation and 0.18 to 0.49° in rotation. The influences of rotation speed on the pose errors were below 0.23 mm and 0.26°. The MIBFT-determined bias, precision, and Rms error were comparable to those of the reported model-based tracking techniques using custom-made synchronous biplane fluoroscopy. The results suggested that the further use of the clinical imaging system is feasible for the noninvasive and precise examination of dynamic joint functions and kinematics in clinical practice and biomechanical research.

Research on Intangible Cultural Heritage Based on Motion Capture

2014 ◽  
Vol 568-570 ◽  
pp. 676-680
Author(s):  
Si Xi Chen ◽  
Shu Chen
Keyword(s):  
Cultural Heritage ◽  
Motion Capture ◽  
Low Cost ◽  
Three Dimensional ◽  
Intangible Cultural Heritage ◽  
Three Dimensional Model ◽  
Motion Data ◽  
Optical Motion ◽  
Capture Method ◽  
Optical Motion Capture

The application of digital technology on the protection of intangible cultural heritage is a major topic of research in recent years. The motion capture technology of protection will gradually replace the traditional recording methods such as texts, pictures and videos. It is valuable to build a high-fidelity, high-modular and low-cost digital platform for choreographic data collection and extended application. This paper studies the intangible cultural heritage of Quanzhou breast-clapping dance, one of the most famous choreographic intangible cultural heritages from China with standard optical motion capture method. The data are acquiring and processing after the dance motion capture, we binds the motion data and three-dimensional model using Motion Builder and build digital demonstration platform base on an OGRE engine to display the movements. The viewer can view at any angle and distance. The system can be easily applied in motion intangible cultural heritages protection project. Furthermore, the system can be provided versatile motion data for additional use.

scholarly journals Optical motion capture dataset of selected techniques in beginner and advanced Kyokushin karate athletes

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Agnieszka Szczęsna ◽  
Monika Błaszczyszyn ◽  
Magdalena Pawlyta
Keyword(s):  
Motion Capture ◽  
Three Dimensional ◽  
Data File ◽  
Human Motion ◽  
Skill Levels ◽  
Human Motion Capture ◽  
Optical Motion ◽  
Optical Motion Capture ◽  
Capture Techniques ◽  
Karate Athletes

AbstractHuman motion capture is commonly used in various fields, including sport, to analyze, understand, and synthesize kinematic and kinetic data. Specialized computer vision and marker-based optical motion capture techniques constitute the gold-standard for accurate and robust human motion capture. The dataset presented consists of recordings of 37 Kyokushin karate athletes of different ages (children, young people, and adults) and skill levels (from 4th dan to 9th kyu) executing the following techniques: reverse lunge punch (Gyaku-Zuki), front kick (Mae-Geri), roundhouse kick (Mawashi-Geri), and spinning back kick (Ushiro-Mawashi-Geri). Each technique was performed approximately three times per recording (i.e., to create a single data file), and under three conditions where participants kicked or punched (i) in the air, (ii) a training shield, or (iii) an opponent. Each participant undertook a minimum of two trials per condition. The data presented was captured using a Vicon optical motion capture system with Plug-In Gait software. Three dimensional trajectories of 39 reflective markers were recorded. The resultant dataset contains a total of 1,411 recordings, with 3,229 single kicks and punches. The recordings are available in C3D file format. The dataset provides the opportunity for kinematic analysis of different combat sport techniques in attacking and defensive situations.

Performance Analysis and Optimization of Flange Bolt Joint under the Influence of Inhomogeneous Temperature Field

2011 ◽  
Vol 121-126 ◽  
pp. 1656-1662
Author(s):  
Qing Wang ◽  
Xian Jun Zhou ◽  
Zhi Liang Liu ◽  
Hong Jie Bi
Keyword(s):  
Temperature Field ◽  
Mechanical Performance ◽  
Three Dimensional ◽  
Inhomogeneous Temperature ◽  
Inhomogeneous Temperature Field ◽  
Joint Parameters ◽  
The Difference ◽  
Disc Spring ◽  
Different Parts ◽  
Better Than

A three-dimensional mechanical model and a transcalent model of flange bolt joint were built, considering the nonlinearity of gasket and the contact problem, the effect of inhomogeneous temperature field and its variation to pressure of bolt and gasket was studied, and the joint parameters of two schemes were compared; based on the orthogonal text, two bolt system schemes, adding disc spring and adding sleeve, were experimentally studied. The investigation showed that the sealability of different parts of the gaskets is different, owing to the difference of each bolt in radial and axial displacement under the influence of inhomogeneous temperature field, and the fatigue of gasket and bolt is easily caused; the scheme of disc spring is better than sleeve, and the disc spring, whose thickness is 0.9mm, was selected to improve the mechanical performance of bolt system.

scholarly journals Biomechanical Evaluation and Strength Test of 3D-Printed Foot Orthoses

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Kuang-Wei Lin ◽  
Chia-Jung Hu ◽  
Wen-Wen Yang ◽  
Li-Wei Chou ◽  
Shun-Hwa Wei ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Motion Capture ◽  
Reaction Force ◽  
Three Dimensional ◽  
Compressive Load ◽  
Foot Orthoses ◽  
Significant Difference ◽  
Optical Motion ◽  
3D Printed ◽  
Optical Motion Capture

Foot orthoses (FOs) are commonly used as interventions for individuals with flatfoot. Advances in technologies such as three-dimensional (3D) scanning and 3D printing have facilitated the fabrication of custom FOs. However, few studies have been conducted on the mechanical properties and biomechanical effects of 3D-printed FOs. The purposes of this study were to evaluate the mechanical properties of 3D-printed FOs and determine their biomechanical effects in individuals with flexible flatfoot. During mechanical testing, a total of 18 FO samples with three orientations (0°, 45°, and 90°) were fabricated and tested. The maximum compressive load and stiffness were calculated. During a motion capture experiment, 12 individuals with flatfoot were enrolled, and the 3D-printed FOs were used as interventions. Kinematic and kinetic data were collected during walking by using an optical motion capture system. A one-way analysis of variance was performed to compare the mechanical parameters among the three build orientations. A paired t-test was conducted to compare the biomechanical variables under two conditions: walking in standard shoes (Shoe) and walking in shoes embedded with FOs (Shoe+FO). The results indicated that the 45° build orientation produced the strongest FOs. In addition, the maximum ankle evertor and external rotator moments under the Shoe+FO condition were significantly reduced by 35% and 16%, respectively, but the maximum ankle plantar flexor moments increased by 3%, compared with the Shoe condition. No significant difference in ground reaction force was observed between the two conditions. This study demonstrated that 3D-printed FOs could alter the ankle joint moments during gait.

Direct Measurements of the Wing Kinematics of a Bat in Straight Flight

2020 ◽  
Vol 143 (4) ◽  
Author(s):  
Sudeep Kumar Singh ◽  
Li-Biao Zhang ◽  
Jing-Shan Zhao
Keyword(s):  
Angle Of Attack ◽  
Three Dimensional ◽  
Leading Edge ◽  
Elastic Membrane ◽  
Wing Kinematics ◽  
Novel Approach ◽  
Dimensional Reconstruction ◽  
Optical Motion ◽  
Optical Motion Capture ◽  
Primary Relationship

Abstract Bat is the only mammal in the nature that can fly. Compared with birds and insects, bats are quite special in that their wings are formed by an elastic membrane, which renders that the airfoil deforms greatly during downstroke and upstroke. Due to the compliant skin of a bat, the movements of its wings are three-dimensionally complex during diverse flight behaviors. To understand the maneuverability and flight performance, three-dimensional reconstruction of the flight kinematics is essential. This study focuses on the reconstruction of the wing kinematics of the bat and identifies the primary relationship of parameters of aerodynamics in straight flight. With markers pasted on the wings and body of a bat, the motions of these points are recorded by a computerized optical motion capture system. The kinematic analysis shows that the motion of wings is very intricate. The digits of the wing display the sign of coupled motion. A novel approach was developed to measure the angle of attack and flapping angle of the wing. The angle of attack of leading edge differs with the overall angle of attack of the wing. The kinematics of the bat's wing is helpful to interpret the secret of the bat's flight.

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