scholarly journals Stride-to-Stride Variability of the Center of Mass in Male Trained Runners After an Exhaustive Run: A Three Dimensional Movement Variability Analysis With a Subject-Specific Anthropometric Model

2021 ◽  
Vol 3 ◽  
Author(s):  
Felix Möhler ◽  
Bernd Stetter ◽  
Hermann Müller ◽  
Thorsten Stein
Keyword(s):  
Center Of Mass ◽  
Three Dimensional ◽  
Vertical Direction ◽  
Uncontrolled Manifold ◽  
Position Vector ◽  
Movement Variability ◽  
Lateral Direction ◽  
Relevant Variable ◽  
The Right ◽  
Trained Runners

The motion of the human body can be described by the motion of its center of mass (CoM). Since the trajectory of the CoM is a crucial variable during running, one can assume that trained runners would try to keep their CoM trajectory constant from stride to stride. However, when exposed to fatigue, runners might have to adapt certain biomechanical parameters. The Uncontrolled Manifold approach (UCM) and the Tolerance, Noise, and Covariation (TNC) approach are used to analyze changes in movement variability while considering the overall task of keeping a certain task relevant variable constant. The purpose of this study was to investigate if and how runners adjust their CoM trajectory during a run to fatigue at a constant speed on a treadmill and how fatigue affects the variability of the CoM trajectory. Additionally, the results obtained with the TNC approach were compared to the results obtained with the UCM analysis in an earlier study on the same dataset. Therefore, two TNC analyses were conducted to assess effects of fatigue on the CoM trajectory from two viewpoints: one analyzing the CoM with respect to a lab coordinate system (PVlab) and another one analyzing the CoM with respect to the right foot (PVfoot). Full body kinematics of 13 healthy young athletes were captured in a rested and in a fatigued state and an anthropometric model was used to calculate the CoM based on the joint angles. Variability was quantified by the coefficient of variation of the length of the position vector of the CoM and by the components Tolerance, Noise, and Covariation which were analyzed both in 3D and the projections in the vertical, anterior-posterior and medio-lateral coordinate axes. Concerning PVlab we found that runners increased their stride-to-stride variability in medio-lateral direction (1%). Concerning PVfoot we found that runners lowered their CoM (4 mm) and increased their stride-to-stride variability in the absorption phase in both 3D and in the vertical direction. Although we identified statistically relevant differences between the two running states, we have to point out that the effects were small (CV ≤ 1%) and must be interpreted cautiously.

scholarly journals The relation between kinematic synergy to stabilize the center of mass during walking and future fall risks: a 1-year longitudinal study

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Momoko Yamagata ◽  
Hiroshige Tateuchi ◽  
Itsuroh Shimizu ◽  
Junya Saeki ◽  
Noriaki Ichihashi
Keyword(s):  
Older Adults ◽  
Center Of Mass ◽  
Three Dimensional ◽  
Vertical Direction ◽  
Frontal Plane ◽  
Community Dwelling ◽  
Uncontrolled Manifold ◽  
Whole Body ◽  
Baseline Visit ◽  
Segmental Coordination

Abstract Background Incorrect body weight shifting is a frequent cause of falls, and the control of the whole-body center of mass (CoM) by segmental coordination is essential during walking. Uncontrolled manifold (UCM) analysis is a method of examining the relation between variance in segmental coordination and CoM stability. However, no prospective cohort study has thoroughly investigated how variance in segmental configurations to stabilize the CoM relates to future falls. This study explored whether variance to stabilize the CoM was related to future falls. Methods At the baseline visit, 30 community-dwelling older adults walked 20 times on a 6-m walkway. Using kinematic data collected during walking by a three-dimensional motion capture system, UCM analysis was performed to investigate how segmental configuration contributes to CoM stability in the frontal plane. One year after the baseline visit, we evaluated whether the subjects experienced falls. Twelve subjects had experienced falls, and 16 had not. Comparisons of variance between older adults with and without falls were conducted by covariate analysis. Results No significant differences in variance were found in the mediolateral direction, whereas in the vertical direction, older adults with fall experiences had a greater variance, reflecting an unstable CoM, than those with no fall experiences. Conclusions We verified that the high variance in segmental configurations that destabilize the CoM in the vertical direction was related to future falls. The variables of UCM analysis can be useful for evaluating fall risk.

MADYMO Simulations of Occupant and Vehicle Kinematics in Offset and Oblique Barrier Tests

2005 ◽  
Author(s):  
Rex T. Shea ◽  
Jiri Kral
Keyword(s):  
Degrees Of Freedom ◽  
Three Dimensional ◽  
Vertical Direction ◽  
Oblique Impact ◽  
Test Method ◽  
Vehicle Interior ◽  
Center Of Rotation ◽  
Frontal Impacts ◽  
Coordinate Origin ◽  
The Right

Oblique and offset impacts occur more frequently than full frontal impacts and the resulting occupant and vehicle kinematics are more complicated. Simulations of these test modes are more involved with added vehicle degrees of freedom. Additional occupant interactions with the vehicle interior need to be considered so that the occupant kinematics can be correlated more accurately. In order to capture the vehicle motion in an offset or oblique impact, a prescribed motion approach is preferred where the vehicle is given a three-dimensional motion with six degrees of freedom. With a planar motion assumption, the dominant angular motion about the vertical direction can be derived from linear accelerations measured at two locations where the vehicle deformation is a minimum. In a previous study the angular kinematics was given to a coordinate origin located on the vehicle centerline and longitudinally near the rear rocker. The instantaneous center of rotation was assumed to be fixed at this point during the event. This is referred to as Method I in this paper. A new approach, referred to as Method II, applied translational displacement to three bodies, which carried the passenger compartment through stiff spring elements. The displacements were integrated from measured accelerations, eliminating the uncertainty of a shifting center of rotation. Both methods assumed the vehicle frame between the front and rear rockers as a rigid body. The IP and steering column intrusions and floor deformations were neglected. The results from both methods were correlated to a pair of 40 kph 30 degree angle impact tests and an IIHS ODB test. Method II showed a slightly better timing correlation for the angle tests and the IIHS ODB test. However, both methods didn’t predict the lateral head contact for the driver in the left angle test and the passenger in the right angle test. More interior details have to be included in the model to capture the lateral motion of the occupants. The prescribed motion method is a more general approach than the commonly used inverse kinematics method, and can be applied to full frontal impact as well. The versatility of the method provides a basis for a modular approach in occupant simulations.

scholarly journals Application of 3D Computed Tomography Reconstruction Images to Assess the Thickness and Dimensions of the Posterior Palatal Seal Area

2019 ◽  
Vol 2019 ◽  
pp. 1-7
Author(s):  
Soeun Lim ◽  
Seoung-Jin Hong ◽  
Joo-Young Ohe ◽  
Janghyun Paek
Keyword(s):  
Computed Tomography ◽  
3D Model ◽  
Three Dimensional ◽  
Ct Images ◽  
Anterior Border ◽  
Lateral Direction ◽  
Mean Dimension ◽  
The Mean ◽  
The Right ◽  
Palatal Mucosa

Few studies have been reported on the scientific measurements of the thickness and dimensions of the posterior palatal seal (PPS) area. The purpose of this study is to measure and analyze the thickness of palatal mucosa by using a three-dimensional (3D) model reconstructed with computed tomography (CT) images and to present objective values by identifying the PPS area. The CT images were reconstructed as a 3D model by separating the maxillary palate mucosa and teeth. Each reconstructed model was analyzed and the thickness was measured at 93 crossing points of each divided plane. The dimension of the PPS area was measured and the right and left dimensions of the PPS area were compared. The thickness of the palatal mucosa was thicker toward the posterior area. The thickness increased in the lateral direction and decreased again. In the PPS area, the mean dimension between the rearmost of anterior border and the most posterior line was 2.19 mm and the mean dimension between the forefront of anterior border and the most posterior line was 5.19 mm in the right side and 5.16 mm in the left side. The mean dimension from the center of the palate to the right most forward point was 6.85 mm, and the left was 7.36 mm. The new measurement method of palatal mucosal thickness is noninvasive, accurate, and easy to store and study, so it can be used effectively in planning and manufacturing the maxillary complete denture in the digital workflows.

scholarly journals Biomecânica aplicada ao polo aquático: revisão de parâmetros cinemáticos e cinéticos da pernada em eggbeater

2016 ◽  
Vol 85 (3) ◽  
Author(s):  
Flávio Antônio de Souza Castro ◽  
Luana Maciel Da Silva
Keyword(s):  
Lift Force ◽  
Three Dimensional ◽  
Vertical Direction ◽  
Lower Limbs ◽  
Water Polo ◽  
De Se ◽  
Biomechanical Parameters ◽  
The Right ◽  
Kinematics And Kinetics ◽  
Kinematics Parameters

Introdução: O eggbeater é uma técnica propulsiva fundamental para o polo aquático. Implica em força resultante propulsiva para cima, sendo utilizada no polo aquático para passes, marcação e chutes a gol.Objetivo: O objetivo desta revisão de literatura foi apresentar e discutir  parâmetros biomecânicos (cinemáticos e cinéticos) relacionados à técnica de execução da pernada de eggbeater.Métodos: As palavras-chave utilizadas para procura dos estudos revisados neste artigo foram: eggbeater kick, water polo e technique, em inglês e português. Foram utilizadas as bases Scopus, Portal Periódico da CAPES e Google Acadêmico. Dezenove estudos foram selecionados para a revisão.Resultados e Discussão: O movimento é caracterizado por uma ação cíclica e alternada dos membros inferiores, ou seja, enquanto a perna esquerda move-se no sentido horário, a perna direita move-se no sentido anti-horário. Estudos demonstram que o movimento não deve ser focado na direção vertical, mas na horizontal (sentido ântero-posterior e médio-lateral) para gerar maior força de sustentação. Em relação à cinemetria, a análise tridimensional parece ser a melhor ferramenta. Já para análise cinética, existe a necessidade de desenvolver tecnologias adequadas à mensuração das forças propulsivas no meio aquático. Ainda, resultados indicam que testes específicos, ou seja, o movimento executado em ambiente aquático mais próximo da realidade de jogo, apresentaram-se mais adequados para avaliar aspectos cinéticos e cinemáticos do movimento em análise.Conclusão: A fim de se incrementar a força de sustentação, a técnica deve ser horizontalizada. Biomechanics Apllied to the Water Polo: Review of Kinetics And Kinematics Parameters of the Eggbeater KickIntroduction: The eggbeater kick is a elementary propulsive technique for the water polo.Objective: The aim of this study was to review the biomechanical parameters (kinematics and kinetics) related to the eggbeater kick, description and analysis.Methods: The keywords used to search for the studies reviewed were: eggbeater kick, water polo and technique, in English and Portuguese. Scopus, CAPES and Google Scholar bases were used.Results and Discussion: The movement is characterized by a cyclic and alternating action of the lower limbs, i.e., while the left leg moves clockwise, the right leg moves in the counterclockwise direction. The eggbeater kick technique promotes a propulsive resultant upward force and it’s used in water polo for passes, marking and shots on goal. Studies have shown that the movement should not be focused in the vertical direction, but horizontally (anteroposterior and mid-lateral) to generate more lift. Regarding to kinematics, the three-dimensional analysis seems to be the best tool. As for kinetic analysis, it is necessary to develop appropriate technologies to measure the propulsive forces in water. Therefore, results indicate that more specific tests, performed in the aquatic enviroment, next to the game’s reality, are more adeqate to asses kinetc and kinematic aspects of the analyzed movement.Conclusion: In order to increase the lift force, the technique should be horizontalized. Development of specific assessments should be encouraged.

Facial Left-Right Dominance in Cleft Lip and Palate: Three-Dimension Evaluation

1994 ◽  
Vol 31 (6) ◽  
pp. 461-465 ◽  
Author(s):  
Frank Ras ◽  
Luc L.M.H. Habets ◽  
Floris C. Van Ginkel ◽  
Birte Prahl-Andersen
Keyword(s):  
Transverse Direction ◽  
Cleft Lip ◽  
Cleft Lip And Palate ◽  
Three Dimensional ◽  
Vertical Direction ◽  
Control Group ◽  
Three Dimension ◽  
Craniofacial Anomalies ◽  
Frequent Use ◽  
The Right

Studies on facial left-right dominance in individuals without craniofacial anomalies have demonstrated controversial results. This is probably due to the frequent use of two-dimensional methods, yet left-right dominance consists of transverse, vertical, and sagittal components. The aim of the present study was to describe three-dimensionally facial left-right dominance in individuals with an operated complete unilateral cleft lip and palate on the left side (LUCLP), on the right side (RUCLP), and in individuals without craniofacial anomalies (controls). Using stereophotogrammetry, three-dimensional coordinates for 16 bilateral and 10 midsagittal facial landmarks were determined for the LUCLP group (N=32), the RUCLP group (N=17), and the control group (N=80). Left-right dominance was measured in three directions. Individuals without craniofacial anomalies showed a facial left sided dominance in the transverse direction, a facial right sided dominance in the sagittal direction, and no particular dominated side in the vertical direction. Individuals with a unilateral cleft lip and palate demonstrated a facial dominance of the nonaffected side in the vertical direction as well as in the sagittal direction, with no particular side dominant in the transverse direction. Generally, there was more variation in left-right dominance within the face in the vertical and sagittal directions.

Drogue-cluster and dye-dispersion measurements

1987 ◽  
Vol 14 (3) ◽  
pp. 320-326 ◽  
Author(s):  
Merv D. Palmer ◽  
Rob Jarvis ◽  
Larry Thompson
Keyword(s):  
Water Surface ◽  
Center Of Mass ◽  
Three Dimensional ◽  
Vertical Direction ◽  
Dispersion Data ◽  
Batch Release ◽  
Surface Dispersion ◽  
The Mean ◽  
The Difference ◽  
Lagrangian Data

Near the water surface, dispersion and transport were extensively measured in the coastal regions of Lake Ontario using dye patches and clusters of water sail and surface drogues. The measurements were carried out for 6–8 h. Each method produced different measurements of dispersion magnitudes with the largest dilution occurring for the dye, followed by sail drogue clusters (40% of the dye's value) and then surface drogue clusters (25% of the dye's value). Both the sail and surface drogues measured the two-dimensional dispersion. The mean surface dispersion was about 50% less than the dispersion 1.5 m below the water surface. The dilution characteristics decreased as the water surface was approached. The sail dispersion was about half of the dye-dispersion data. It was not known how much of the difference was attributable to the dye being three-dimensional and affected by dispersion in the vertical direction; consequently, as time progressed, the dye patch was measuring dispersion at greater depth than the water sail drogues, which were set for a depth 1.5 m below the water surface. The statistical increase of the variance with time was computed for each method of measuring dispersion, and the results were compared. A method for predicting dilution envelopes for a location using the path lines of the drogue-cluster centroids or center of mass of the dye patch was developed for both a batch release and a continuous discharge. These dilution envelopes are based entirely on Lagrangian data for both the velocity and dispersion estimates. Key words: lake, dispersion, drogue clusters, dye, surface streaking.

The Relation of Kinematic Synergy to Stabilize the Center of Mass During Walking With Future Falls: A 1-Year Longitudinal Study

2020 ◽  
Author(s):  
Momoko Yamagata ◽  
Hiroshige Tateuchi ◽  
Itsuroh Shimizu ◽  
Junya Saeki ◽  
Noriaki Ichihashi
Keyword(s):  
Older Adults ◽  
Center Of Mass ◽  
Vertical Direction ◽  
Frontal Plane ◽  
Community Dwelling ◽  
Uncontrolled Manifold ◽  
Baseline Visit ◽  
Segmental Coordination ◽  
One Year ◽  
Base Of Support

Abstract Background: An incorrect transfer of center of mass (CoM) to outside the base of support is a frequent cause of falls, and segmental coordination to control CoM is crucial during walking. Uncontrolled manifold (UCM) analysis is a method of examining the relation between variances in segmental coordination and the CoM stability. However, no study has investigated through a prospective cohort study how variance in segmental configurations to stabilize CoM relates to future falls. This study explored whether variances to stabilize the CoM were related to future falls.Methods: At the baseline visit, 30 community-dwelling older adults walked 20 times on a 6-m walkway. Using kinematic data during walking, UCM analysis was performed to investigate how segmental configuration contributes to the CoM stability in the frontal plane. One year after the baseline visit, we evaluated whether the subjects experienced falls; 12 had experienced falls and 16 had not. Comparisons of variances between older adults with and without falls were conducted by covariate analysis.Results: No significant differences in variances were found in the mediolateral direction, whereas in the vertical direction, older adults with fall experiences had a greater variance, reflecting unstable CoM, than those with no fall experiences.Conclusions: We verified that the high variance in segmental configurations that destabilize CoM in the vertical direction was related to future falls. The variables of UCM analysis can be useful to evaluate fall risks.

Center of Mass Theorem and the Separation of Variables for Two-Body System on a Three-Dimensional Sphere

2020 ◽  
Vol 23 (3) ◽  
pp. 306-311
Author(s):  
Yu. Kurochkin ◽  
Dz. Shoukavy ◽  
I. Boyarina
Keyword(s):  
Constant Curvature ◽  
Jacobi Equation ◽  
Separation Of Variables ◽  
Center Of Mass ◽  
Three Dimensional ◽  
Relative Distance ◽  
Dimensional Sphere ◽  
Body System ◽  
Spaces Of Constant Curvature ◽  
Hamilton Jacobi Equation

The immobility of the center of mass in spaces of constant curvature is postulated based on its definition obtained in [1]. The system of two particles which interact through a potential depending only on the distance between particles on a three-dimensional sphere is considered. The Hamilton-Jacobi equation is formulated and its solutions and trajectory equations are found. It was established that the reduced mass of the system depends on the relative distance.

About the Development of Brick-Design in Russia

2020 ◽  
Vol 787 (12) ◽  
pp. 21-24
Author(s):  
Y.A. Bozhko ◽  
◽  
K.A. Lapunova ◽  
Keyword(s):  
Functional Role ◽  
Three Dimensional ◽  
Vertical Direction ◽  
Basic Unit ◽  
Design Development ◽  
European Cities ◽  
Unique Material ◽  
Decisive Action ◽  
Color Combinations ◽  
Insufficient Number

The article reflects the authors view on the technical and aesthetic side of the use of face bricks in the architecture of our country. The term brick design combines such indicators of brickwork as the color, size and surface of the brick itself, as well as the type of masonry and seam parameters. Unfortunately, the analysis of the current situation shows that the culture of consumption of face bricks in Russia remains at a low level, which is due to the lack of proper knowledge and insufficient number of qualified master masons. The main goal of brick design development is to popularize various types of three-dimensional masonry and reveal the potential of using bricks as a basic unit. The comparison shows the architecture of European cities, which does not differ in the complexity of architectural forms, but has advantages in the form of unusual masonry, color combinations, vertical direction of masonry and other elements of technical aesthetics. The use of bricks in various levels of brick design will allow you to avoid using architectural decoration on the facades of buildings, while preserving its authenticity and individuality. The brick, as a basic unit, is self-sufficient and is able to fulfill not only its functional role, but also its aesthetic one. In this situation, a necessary and decisive action will be competent communication with industry specialists, architects and designers, leading manufacturers and technologists who realize that we have a unique material that does not need additional wrapping when used efficiently.

scholarly journals Right-sided Bochdalek hernia in an adult with hepatic malformation and intestinal malrotation

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Naoki Enomoto ◽  
Kazuhiko Yamada ◽  
Daiki Kato ◽  
Shusuke Yagi ◽  
Hitomi Wake ◽  
...  
Keyword(s):  
Elective Surgery ◽  
Abdominal Cavity ◽  
Three Dimensional ◽  
Simulation Software ◽  
3D Simulation ◽  
Diaphragmatic Defect ◽  
Intestinal Malrotation ◽  
Intestinal Loop ◽  
Bochdalek Hernia ◽  
The Right

Abstract Background Bochdalek hernia is a common congenital diaphragmatic defect that usually manifests with cardiopulmonary insufficiency in neonates. It is very rare in adults, and symptomatic cases are mostly left-sided. Diaphragmatic defects generally warrant immediate surgical intervention to reduce the risk of incarceration or strangulation of the displaced viscera. Case presentation A 47-year-old woman presented with dyspnea on exertion. Computed tomography revealed that a large part of the intestinal loop with superior mesenteric vessels and the right kidney were displaced into the right thoracic cavity. Preoperative three-dimensional (3D) simulation software visualized detailed anatomy of displaced viscera and the precise location and size of the diaphragmatic defect. She underwent elective surgery after concomitant pulmonary hypertension was stabilized preoperatively. The laparotomic approach was adopted. Malformation of the liver and the presence of intestinal malrotation were confirmed during the operation. The distal part of the duodenum, jejunum, ileum, colon, and right kidney were reduced into the abdominal cavity consecutively. A large-sized oval defect was closed with monofilament polypropylene mesh. No complications occurred postoperatively. Conclusion Symptomatic right-sided Bochdalek hernia in adults is exceedingly rare and is frequently accompanied by various visceral anomalies. Accurate diagnosis and appropriate surgical repair are crucial to prevent possible incarceration or strangulation. The preoperative 3D simulation provided comprehensive information on anatomy and concomitant anomalies and helped surgeons plan the operation meticulously and perform procedures safely.

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