scholarly journals Arm waving in stylophoran echinoderms: three-dimensional mobility analysis illuminates cornute locomotion

2020 ◽  
Vol 7 (6) ◽  
pp. 200191 ◽  
Author(s):  
Elizabeth G. Clark ◽  
John R. Hutchinson ◽  
Peter J. Bishop ◽  
Derek E. G. Briggs
Keyword(s):  
Range Of Motion ◽  
Three Dimensional ◽  
Lateral Movement ◽  
Mobility Analysis ◽  
Early Ordovician ◽  
Digital Modelling ◽  
Rigid Skeleton

The locomotion strategies of fossil invertebrates are typically interpreted on the basis of morphological descriptions. However, it has been shown that homologous structures with disparate morphologies in extant invertebrates do not necessarily correlate with differences in their locomotory capability. Here, we present a new methodology for analysing locomotion in fossil invertebrates with a rigid skeleton through an investigation of a cornute stylophoran, an extinct fossil echinoderm with enigmatic morphology that has made its mode of locomotion difficult to reconstruct. We determined the range of motion of a stylophoran arm based on digitized three-dimensional morphology of an early Ordovician form, Phyllocystis crassimarginata . Our analysis showed that efficient arm-forward epifaunal locomotion based on dorsoventral movements, as previously hypothesized for cornute stylophorans, was not possible for this taxon; locomotion driven primarily by lateral movement of the proximal aulacophore was more likely. Three-dimensional digital modelling provides an objective and rigorous methodology for illuminating the movement capabilities and locomotion strategies of fossil invertebrates.

Three-Dimensional Torso Motion in Tethered Front Crawl Stroke and its Implications on Low Back Pain

2016 ◽  
Vol 32 (1) ◽  
pp. 50-58 ◽  
Author(s):  
Tanghuizi Du ◽  
Ikumi Narita ◽  
Toshimasa Yanai
Keyword(s):  
Low Back Pain ◽  
Back Pain ◽  
Range Of Motion ◽  
Twist Angle ◽  
Three Dimensional ◽  
Low Back ◽  
Front Crawl ◽  
Active Range Of Motion ◽  
High Incidence ◽  
Competitive Swimmers

Low back pain is a common problem among competitive swimmers, and repeated torso hyperextension is claimed to be an etiological factor. The purpose of this study was to describe the three-dimensional torso configurations in the front crawl stroke and to test the hypothesis that swimmers experience torso hyperextension consistently across the stroke cycles. Nineteen collegiate swimmers underwent 2 measurements: a measurement of the active range of motion in 3 dimensions and a measurement of tethered front crawl stroke at their maximal effort. Torso extension beyond the active range of torso motion was defined as torso hyperextension. The largest torso extension angle exhibited during the stroke cycles was 9 ± 11° and it was recorded at or around 0.02 ± 0.08 s, the instant at which the torso attained the largest twist angle. No participant hyperextended the torso consistently across the stroke cycles and subjects exhibited torso extension angles during tethered front crawl swimming that were much less than their active range of motion. Therefore, our hypothesis was rejected, and the data suggest that repeated torso hyperextension during front crawl strokes should not be claimed to be the major cause of the high incidence of low back pain in swimmers.

scholarly journals Imagens táteis tridimensionais: um modelo para a tradução tátil a partir de imagens estáticas bidimensionais | Three-dimensional tactile images: a model for tactile translation from two-dimensional static images

2017 ◽  
Vol 14 (2) ◽  
pp. 234-252
Author(s):  
Emilia Christie Picelli Sanches ◽  
Claudia Mara Scudelari Macedo ◽  
Juliana Bueno
Keyword(s):  
Visual Information ◽  
Three Dimensional ◽  
Information Design ◽  
Blind People ◽  
Two Dimensional ◽  
Test Results ◽  
Visual Content ◽  
Tactile Sense ◽  
Digital Modelling ◽  
Static Images

A acessibilidade na educação de pessoas cegas é um direito que deve ser cumprido. Levando-se em consideração que o design da informação almeja transmitir uma informação de forma efetiva ao receptor, e que uma imagem estática precisa ser adaptada para que um aluno cego tenha acesso a esse conteúdo visual, propõe-se uma maneira de traduzir a informação visual para o tátil. O propósito deste artigo, então, é apresentar um modelo para tradução de imagens estáticas bidimensionais em imagens táteis tridimensionais. Por isso, parte de uma breve revisão da literatura sobre cegueira, percepção tátil e imagens táteis. Na sequência, apresenta o modelo de tradução em três partes: (1) recomendações da literatura; (2) estrutura e (3) modelo preliminar para teste. Depois, descreve o teste do modelo realizado com dois designers com habilidades de modelagem digital (potenciais usuários). Como resultado dos testes, obtiveram-se duas modelagens distintas, uma utilizando da elevação e outra utilizando texturas, porém, os dois participantes realizaram com sucesso a tarefa pretendida. Ainda, a partir dos resultados dos obtidos, também, foi possível perceber falhas no modelo que necessitam ser ajustadas para as próximas etapas da pesquisa.+++++Accessibility in education of blind people is a right that must be fulfilled. Considering that information design aims to transmit an information in an effective way to the receiver, and that a static image needs to be adapted so that a blind student can have access to this visual content, it is proposed a way to translate the visual information to the tactile sense. The purpose of this paper is to present a translating model of static two-dimensional images into three-dimensional tactile images. First, it starts from a brief literature review aboutblindness, tactile perception and tactile images. Second, it presents the translating model in three sections: (1) literature recommendations; (2) structure and (3) finished model for testing. Then, it describes the tests with the model and two designers with digital modelling abilities (potential users). As a result from the tests, two distinct models were obtained, one using elevation and other using textures, although, both participants successfully made the intended task. Also from the test results, it was possible to perceive flaws on the model that need to be adjusted for the next steps of the research.

Comparision of Cup Anteversion and Tilt Effects on Dislocation Propensity for Small-Head-Size Total Hip Replacements

2000 ◽  
Author(s):  
Mark E. Nadzadi ◽  
Douglas R. Pedersen ◽  
John J. Callaghan ◽  
Thomas D. Brown
Keyword(s):  
Range Of Motion ◽  
Three Dimensional ◽  
Element Model ◽  
Head Size ◽  
Modular System ◽  
Total Hip ◽  
Total Hip Replacements ◽  
Apparent Stiffness ◽  
Hip Replacements ◽  
Laboratory Examinations

Abstract While dislocation is a leading cause of total hip replacement failure, empirical observations far outnumber systematic laboratory examinations of this phenomenon. A previously validated three-dimensional, non-linear, contact finite element model was used to study how surgical placement affects dislocation propensity. The computational model employed a widely used 22mm modular system, and examined range of motion prior to impingement as well as peak moment developed to resist dislocation under a typical leg-crossing maneuver. Results were compared to a previous study of an otherwise similar 26mm modular head system, using the same formulation. Similar trends occurred. Increasing tilt and/or anteversion increased both the range of motion and the peak resisting moment, while apparent stiffness seemed to be unaffected. Further, impingement range of motion was independent of head size, but peak resisting moment was nearly 25% less for the 22mm head sizes.

Assessing Spatial Design in Virtual Environments

2014 ◽  
pp. 74-123 ◽  
Author(s):  
Andrew Cram ◽  
Russell Lowe ◽  
Katy Lumkin
Keyword(s):  
Virtual Environments ◽  
Collaborative Design ◽  
Three Dimensional ◽  
Spatial Design ◽  
Student Cohorts ◽  
Assessment Techniques ◽  
Modelling Techniques ◽  
Digital Modelling ◽  
Work Samples ◽  
Support Students

There is growing interest in adopting three-dimensional virtual environments within spatial design courses to use digital modelling techniques to support students' learning. One pedagogical issue that has received little attention so far is the question of how 3D virtual environments can be used to implement assessment techniques that support students' learning of spatial design expertise. This chapter seeks to assist spatial design educators who are considering digital modelling by presenting two case studies that highlight assessment practices within spatial design courses using virtual environments. Rubrics and student work samples are included. These courses both involve students creating architectural designs within virtual environments, yet contrast in several ways: learning outcomes, 3D modelling technologies, and student cohorts. The cases examine how the affordances of virtual environments for iterative, immersive, and collaborative design can enable formative and summative assessment, with both design process and the final artefact playing important roles.

Reconstructive Architectural and Urban Digital Modelling

2018 ◽  
pp. 7856-7868
Author(s):  
Roberta Spallone
Keyword(s):  
Case Studies ◽  
Three Dimensional ◽  
Graphical Analysis ◽  
Basic Data ◽  
Three Dimensional Modeling ◽  
Digital Reconstruction ◽  
Dimensional Modeling ◽  
Original Shape ◽  
Methods And Techniques ◽  
Digital Modelling

The digital reconstruction of architectural and urban complexes which were demolished, transformed or have been only theoretically conceived, remaining 'on paper', is now a tool of considerable heuristic value, allowing to preserve, interpret and create new images of cultural heritages that no longer exist in their original shape or never reached a material construction. The tools, methods and techniques of representation (graphical analysis, two and three-dimensional modeling, animation, prototyping) should be carefully chosen, case by case, in order to interpret properly the basic data and create original interpretations, using as research sources and ideas not only the archival drawings and any surviving vestiges, but also the autograph writings and the more inspired analysis developed by the architecture critics. The examination of several international case studies, and also some experiences personally conducted highlights the different strategies used for the preservation of the memory of such heritage.

In-vivo three-dimensional motion analysis of the wrist during dart-throwing motion after midcarpal fusion and radioscapholunate fusion

2020 ◽  
Vol 45 (5) ◽  
pp. 501-507
Author(s):  
Lisa Reissner ◽  
Olga Politikou ◽  
Gabriella Fischer ◽  
Maurizio Calcagni
Keyword(s):  
Range Of Motion ◽  
Motion Capture ◽  
Three Dimensional ◽  
Healthy Controls ◽  
Dart Throwing ◽  
Radioscapholunate Fusion ◽  
Infrared Cameras ◽  
Basic Motion ◽  
Throwing Motion

We recorded the dart-throwing motion and basic motion tasks in patients following radioscapholunate fusion and midcarpal fusion with a three-dimensional motion capture system in vivo, using digital infrared cameras to track the movement of reflective skin markers on the hand and forearm. During the dart-throwing motion, 20 healthy volunteers showed a median range of motion of 107°. As expected, patients had significantly reduced wrist range of motion during basic motion tasks and dart-throwing motion compared with the healthy controls, except for ulnar flexion occurring in the dart-throwing motion in patients treated by midcarpal fusion and radial deviation after midcarpal fusion or radioscapholunate fusion. In addition, patients who had undergone radioscapholunate fusion had significantly reduced range of motion during dart-throwing motion compared with patients after midcarpal fusion.

A three-dimensional printed patient-specific scaphoid replacement: a cadaveric study

2018 ◽  
Vol 43 (4) ◽  
pp. 407-412 ◽  
Author(s):  
Philipp Honigmann ◽  
Ralf Schumacher ◽  
Romy Marek ◽  
Franz Büttner ◽  
Florian Thieringer ◽  
...  
Keyword(s):  
Range Of Motion ◽  
Three Dimensional ◽  
Cadaveric Study ◽  
Patient Specific ◽  
Test Results ◽  
Physiological Range

We present our first cadaveric test results of a three-dimensional printed patient-specific scaphoid replacement with tendon suspension, which showed normal motion behaviour and preservation of a stable scapholunate interval during physiological range of motion.

Relationship Between Weightbearing Ankle Dorsiflexion Passive Range of Motion and Ankle Kinematics During Gait

2017 ◽  
Vol 107 (1) ◽  
pp. 39-45 ◽  
Author(s):  
Min-Hyeok Kang ◽  
Jae-Seop Oh
Keyword(s):  
Range Of Motion ◽  
Three Dimensional ◽  
Knee Extension ◽  
Ankle Dorsiflexion ◽  
Physically Active ◽  
Ankle Kinematics ◽  
The Difference ◽  
Analysis System ◽  
The Relationship ◽  
Paired T Test

Background: Measurement of weightbearing ankle dorsiflexion (DF) passive range of motion (PROM) has been suggested as a way to estimate ankle kinematics during gait; however, no previous study has demonstrated the relationship between ankle DF during gait and ankle DF PROM with knee extension. We examine the relationship between maximum ankle DF during gait and nonweightbearing and weightbearing ankle DF PROM with knee extension. Methods: Forty physically active individuals (mean ± SD age, 21.63 ± 1.73 years) participated in this study. Ankle DF PROM with knee extension was measured in the nonweightbearing and weightbearing conditions; maximum ankle DF during gait was assessed using a three-dimensional motion analysis system. The relationship between each variable was calculated using the Pearson product moment correlation coefficient, and the difference in ankle DF PROM between the nonweightbearing and weightbearing conditions was analyzed using a paired t test. Results: The weightbearing measurement (r = 0.521; P < .001) for ankle DF PROM showed a greater correlation with maximum ankle DF during gait than did the nonweightbearing measurement (r = 0.245; P = .029). Ankle DF PROM was significantly greater in the weightbearing than in the nonweightbearing condition (P < .001) despite a significant correlation between the two measurements (r = 0.402; P < .001). Conclusions: These findings indicate that nonweightbearing and weightbearing measurements of ankle DF PROM with knee extension should not be used interchangeably and that weightbearing ankle DF PROM with the knee extended is more appropriate for estimating ankle DF during gait.

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