scholarly journals Biomechanical analyses of the performance of Paralympians: from foundation to elite level

2012 ◽  
Vol 36 (3) ◽  
pp. 380-395 ◽  
Author(s):  
Sarah A Curran ◽  
Laurent Frossard
Keyword(s):  
Performance Analysis ◽  
Three Dimensional ◽  
The Body ◽  
Biomechanical Analysis ◽  
Sports Performance ◽  
London 2012 ◽  
Elite Level ◽  
Complexity Constraints ◽  
User Friendly

A biomechanical analysis of sports performance provides an objective method of determining performance of a particular sporting technique. In particular, it aims to add to the understanding of the mechanisms influencing performance, characterization of athletes and provide insights into injury predisposition. While the performance in sport of able-bodied athletes is well recognized in the literature, less information and understanding are known on the complexity, constraints and demands placed on the body of an individual with a disability. This article provides a dialogue that outlines scientific issues of the performance analysis of multi-level athletes with a disability, including Paralympians. Four integrated themes are explored, the first of which focuses on how biomechanics can contribute to the understanding of sports performance in athletes with a disability and how it may be used as an evidence-based tool. This latter point questions the potential for a possible cultural shift led by the emergence of user-friendly instruments. The second theme briefly discusses the role of reliability of sports performance and addresses the debate of two-dimensional and three-dimensional analyses. The third theme addresses key biomechanical parameters and provides guidance to clinicians and coaches on the approaches adopted using the biomechanical/sports performance analysis for an athlete with a disability starting out, to the emerging and elite Paralympian. For completeness of this discourse, the final theme is based on the controversial issues on the role of assisted devices, and the inclusion of Paralympians into able-bodied sport. All combined, this dialogue highlights the intricate relationship between biomechanics and training of individuals with a disability. Furthermore, it illustrates the complexity of modern training of athletes, which can only lead to a better appreciation of the performances to be delivered in the London 2012 Paralympic Games. Clinical relevance Biomechanical analysis can play a fundamental role in optimizing the performance of an athlete with a disability. Clinicians should be aware and understand the mechanisms that may influence performance and have an appreciation of the factors that may predispose such athletes to injury.

scholarly journals Role of Oral and Gut Microbiota in Dietary Nitrate Metabolism and Its Impact on Sports Performance

Nutrients ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3611
Author(s):  
Rocío González-Soltero ◽  
María Bailén ◽  
Beatriz de Lucas ◽  
Maria Isabel Ramírez-Goercke ◽  
Helios Pareja-Galeano ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Gut Microbiota ◽  
Oral Bacteria ◽  
The Body ◽  
Sports Performance ◽  
Dietary Nitrate ◽  
Dietary Strategy ◽  
Nitrate Metabolism ◽  
Nitrate Supplementation

Nitrate supplementation is an effective, evidence-based dietary strategy for enhancing sports performance. The effects of dietary nitrate seem to be mediated by the ability of oral bacteria to reduce nitrate to nitrite, thus increasing the levels of nitrite in circulation that may be further reduced to nitric oxide in the body. The gut microbiota has been recently implicated in sports performance by improving muscle function through the supply of certain metabolites. In this line, skeletal muscle can also serve as a reservoir of nitrate. Here we review the bacteria of the oral cavity involved in the reduction of nitrate to nitrite and the possible changes induced by nitrite and their effect on gastrointestinal balance and gut microbiota homeostasis. The potential role of gut bacteria in the reduction of nitrate to nitrite and as a supplier of the signaling molecule nitric oxide to the blood circulation and muscles has not been explored in any great detail.

A Biomechanical Analysis of Manual Materials Handling Tasks in Restricted Working Postures

1988 ◽  
Vol 32 (11) ◽  
pp. 670-674 ◽  
Author(s):  
Sean Gallagher ◽  
Richard L. Unger
Keyword(s):  
Lumbar Spine ◽  
Three Dimensional ◽  
The Body ◽  
Biomechanical Analysis ◽  
Body Type ◽  
Materials Handling ◽  
The Subject ◽  
Kneeling Work ◽  
Centers Of Mass ◽  
Three Dimensional Coordinate

The U. S. Bureau of Mines has developed a biomechanical modeling system to examine the stresses on the lumbar spine when lifting in stooped and kneeling work postures utilized by low-seam underground coal miners. This system allows Bureau researchers to digitize two videotaped views (frontal and sagittal) of underground miners performing various lifting tasks under laboratory conditions. These points are then translated into a three-dimensional coordinate system, and a link man (developed from known anthropometry of the subject) is fitted to the 3-D coordinates. The centers of mass for the various links are calculated according to the body type (rotund, muscular, thin, or median) of the subject. Compression results were estimated using a linear programming internal/external load model. The location of the L3 vertebral body center was calculated based upon anthropometric data and morphometric studies of the lumbar spine. Results of the compression and shear force analyses for restricted lifting postures are presented and discussed.

scholarly journals Activation becomes highly organized during long-duration ventricular fibrillation in canine hearts

2010 ◽  
Vol 298 (6) ◽  
pp. H2046-H2053 ◽  
Author(s):  
Li Li ◽  
Qi Jin ◽  
Derek J. Dosdall ◽  
Jian Huang ◽  
Steven M. Pogwizd ◽  
...  
Keyword(s):  
Ventricular Fibrillation ◽  
Conduction Block ◽  
Three Dimensional ◽  
Left Ventricular ◽  
The Body ◽  
Long Duration ◽  
Surface Ecg ◽  
Electrode Matrix ◽  
Different Levels

Little is known about the three-dimensional (3-D) intramural activation sequences during long-duration ventricular fibrillation (VF), including the role of the subendocardium and its Purkinje fibers (PFs) in long-duration VF maintenance. Our aim was to explore the mechanism of long-duration VF maintenance with 3-D electrical mapping. We recorded 10 min of electrically induced VF in the left ventricular anterior free wall of six 10-kg, open-chest dogs using a 3-D transmural unipolar electrode matrix (9 × 9 × 6, 2-mm spacing) that allowed us to map intramural activation sequences. At 2.5 ± 1.8 min of VF, although the body surface ECG continued to exhibit a disorganized VF pattern, intramurally a more organized, synchronous activation pattern was first observed [locally synchronized VF (LSVF)]. This pattern occurred one or more times in all dogs and was present 33.4 ± 31.4% of the time during 5–10 min of VF. As opposed to the preceding changing complex activation sequences of VF, during LSVF, wavefronts were large and highly repeatable near the endocardium, first exciting the endocardium almost simultaneously and then rapidly spreading toward the epicardium with different levels of conduction block en route. During LSVF, PF activations always preceded working myocardium activations near the endocardium. In conclusion, long-duration VF in dogs frequently becomes highly organized in the subendocardium, with activation fronts arising in this region and passing intramurally toward the epicardium, even though the surface ECG continues to exhibit a disorganized pattern. PFs appear to play an important role during this stage of VF.

Effect of confinement on three-dimensional stability in the wake of a circular cylinder

2009 ◽  
Vol 642 ◽  
pp. 477-487 ◽  
Author(s):  
SIMONE CAMARRI ◽  
FLAVIO GIANNETTI
Keyword(s):  
Stability Analysis ◽  
Circular Cylinder ◽  
Linear Stability ◽  
Linear Stability Analysis ◽  
Dimensional Stability ◽  
Opposite Sign ◽  
Three Dimensional ◽  
The Body ◽  
Karman Street

This paper investigates the three-dimensional stability of the wake behind a symmetrically confined circular cylinder by a linear stability analysis. Emphasis has been placed on discussing analogies and differences with the unconfined case to highlight the role of the inversion of the von Kármán street in the nature of the three-dimensional transition. Indeed, in this flow, the vortices of opposite sign that are alternately shed from the body into the wake cross the symmetry line further downstream and they assume a final configuration which is inverted with respect to the unconfined case. It is shown that the transition to a three-dimensional state has the same space–time symmetries of the unconfined case, although the shape of the linearly unstable modes is affected by the inversion of the wake vortices. A possible interpretation of this result is given here.

scholarly journals Biomechanical Analysis of Successful and Unsuccessful Snatch Lifts in Elite Female Weightlifters

2019 ◽  
Vol 68 (1) ◽  
pp. 69-79 ◽  
Author(s):  
Andrzej Mastalerz ◽  
Paulina Szyszka ◽  
Weronika Grantham ◽  
Jerzy Sadowski
Keyword(s):  
Performance Analysis ◽  
Body Movement ◽  
Center Of Gravity ◽  
The Body ◽  
Biomechanical Analysis ◽  
Hip Joints ◽  
Factors Affecting ◽  
Analysis System ◽  
Biomechanical Factors

AbstractThe aim of this study was to identify biomechanical factors affecting successful and unsuccessful snatch attempts in elite female weightlifters during the 2013 World Weightlifting Championships. Fourteen female competitors took part in this study. Their successful and unsuccessful snatch lifts with the same load were recorded with 2 camcorders (50 Hz), and selected points were digitized manually on to the body and the barbell using the Ariel Performance Analysis System. The kinetic and kinematic barbell movement as well as the athlete’s body movement variables during the liftoff phase were examined. The results of this study show statistical differences (p ≤ 0.05) between successful and unsuccessful attempts in relation to the angle values in the knee and hip joints in preparation for the aerial phase position. Similarly, the center of gravity velocity was significantly higher in successful attempts during the catch phase. Thus, coaches should pay particular attention to the accuracy of the execution in preparation for the aerial phase position and to the velocity of the center of gravity of the competitors during the catch phase.

The Motion of Euglena Viridis: The Role of Flagella

1966 ◽  
Vol 44 (3) ◽  
pp. 579-588 ◽  
Author(s):  
M. E. J. HOLWILL
Keyword(s):  
Theoretical Analysis ◽  
High Speed ◽  
Body Movement ◽  
Three Dimensional ◽  
The Body ◽  
Propulsive Force

1. Analysis of high-speed cine-films of Euglena viridis reveal that the organism traverses a complex three-dimensional path while helical waves are propagated from base to tip along the flagellum. 2. Theoretical analysis shows that the rapid forward velocity of the organism cannot be produced by the body movement alone. The propulsive force generated by the flagellum is sufficient to maintain the observed velocities. 3. Although the euglenoid flagellum bears mastigonemes the thrust produced by it is in the direction to be expected if the flagellum were smooth. Possible explanations of this observation are given.

scholarly journals Game Performance Evaluation in Male Goalball Players

2015 ◽  
Vol 48 (1) ◽  
pp. 43-51 ◽  
Author(s):  
Bartosz Molik ◽  
Natalia Morgulec-Adamowicz ◽  
Andrzej Kosmol ◽  
Krzysztof Perkowski ◽  
Grzegorz Bednarczuk ◽  
...  
Keyword(s):  
Visual Impairment ◽  
Body Mass ◽  
Body Height ◽  
The Body ◽  
London 2012 ◽  
Arm Span ◽  
Elite Level ◽  
Paralympic Sport ◽  
Total Blindness ◽  
Game Performance

AbstractGoalball is a Paralympic sport exclusively for athletes who are visually impaired and blind. The aims of this study were twofold: to describe game performance of elite male goalball players based upon the degree of visual impairment, and to determine if game performance was related to anthropometric characteristics of elite male goalball players. The study sample consisted of 44 male goalball athletes. A total of 38 games were recorded during the Summer Paralympic Games in London 2012. Observations were reported using the Game Efficiency Sheet for Goalball. Additional anthropometric measurements included body mass (kg), body height (cm), the arm span (cm) and length of the body in the defensive position (cm). The results differentiating both groups showed that the players with total blindness obtained higher means than the players with visual impairment for game indicators such as the sum of defense (p = 0.03) and the sum of good defense (p = 0.04). The players with visual impairment obtained higher results than those with total blindness for attack efficiency (p = 0.04), the sum of penalty defenses (p = 0.01), and fouls (p = 0.01). The study showed that athletes with blindness demonstrated higher game performance in defence. However, athletes with visual impairment presented higher efficiency in offensive actions. The analyses confirmed that body mass, body height, the arm span and length of the body in the defensive position did not differentiate players’ performance at the elite level.

Development of body force model for steady inlet distortions in high-speed multistage compressor

2016 ◽  
Vol 231 (9) ◽  
pp. 1650-1659 ◽  
Author(s):  
Jin Guo ◽  
Jun Hu
Keyword(s):  
Performance Analysis ◽  
Body Force ◽  
Three Dimensional ◽  
Aerodynamic Performance ◽  
The Body ◽  
Force Model ◽  
Source Terms ◽  
Analysis Model ◽  
Multistage Compressor ◽  
The Impact

This study aims at establishing a three-dimensional numerical model, compressor aerodynamic performance analysis model, to simulate the impact of complicated distorted flow on multistage axial flow compressor based on the body force model. The model solves the compressible three-dimensional Euler equations, which are modified to include source terms representing the effect of the blade rows. In this study, the association between blade source terms and entry Mach number together with attack angle could be established with the deviation angle model and loss model. In this paper, compressor aerodynamic performance analysis model is used to evaluate the effect of inlet circumferential total pressure distortion and swirl distortion on a five-stage high-pressure compressor. Calculated operating maps for compressor agree well with the experimental results. Meanwhile, the traveling process of inlet distortions in the multistage compressor is correctly revealed. The wide application prospect of the model can be seen in the area of inlet distortion problems.

scholarly journals An Effective Three-Dimensional Layout of Actuation Body Force for Separation Control

2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
Ittetsu Kaneda ◽  
Satoshi Sekimoto ◽  
Taku Nonomura ◽  
Kengo Asada ◽  
Akira Oyama ◽  
...  
Keyword(s):  
Body Force ◽  
Separation Bubble ◽  
Three Dimensional ◽  
Separated Flow ◽  
Flow Fields ◽  
The Body ◽  
Large Eddy Simulations ◽  
Separation Control ◽  
Large Eddy

We conducted large eddy simulations of the control of separated flow over an airfoil using body forces and discuss the role of a three-dimensional vortex structure in separation control. Two types of cases are examined: (1) the body force is distributed in a spanwise uniform layout and (2) the body force is distributed in a spanwise intermittent layout, with three-dimensional vortices being expected to be generated in the latter cases. The flow fields in the latter cases have a shorter separation bubble than those in the former cases although the total momentum of the body force in the latter cases is the same as or half of the former cases. In the flow fields of the latter type, the three-dimensional vortices, which are not observed in the former cases, are generated by the body force downstream of the body force distributed. Thus, three-dimensional vortices are considered to be effective in controlling the separated flow.

Attending to the disembodied character in research on professional narratives

2011 ◽  
Vol 21 (2) ◽  
pp. 238-257 ◽  
Author(s):  
Julie-Ann Scott
Keyword(s):  
Performance Analysis ◽  
Personal Narratives ◽  
The Body ◽  
Physically Disabled ◽  
Tragic Hero ◽  
Insight Into

This essay provides a rationale of how Performance Analysis and Narrative Positioning within research on Physically Disabled Professionals’ Personal Narratives can provide insight into the role of the body in the analysis of professional narratives. Through analyzing the participants’ open-ended narratives as performances in which the narrators draw upon performativities to reconcile the absurdity associated with their deemed ‘unprofessional’ bodies legitimately occupying a professional space, the author traces the emergence of embodied professional heroes in four variations: the Super Hero, Warrior Hero, Tragic Hero, and Rogue Hero, each which illuminates the importance of the body in the construction of personal narratives of professionalism. In conclusion, the author calls for attention to the potential performance of the Anti Hero across personal narratives that emerge in unmarked bodies in order to attend the underlying performativities and discourses of power within all narratives of professionalism.

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