Simulations of dolphin kick swimming using smoothed particle hydrodynamics

Mathematics, Informatics & Statistics, CSIRO, Gate 5 Normanby Rd., Clayton, VIC 3168, Australia.
Human movement science (Impact Factor: 1.6). 08/2011; 31(3):604-19. DOI: 10.1016/j.humov.2011.06.008
Source: PubMed


In competitive human swimming the submerged dolphin kick stroke (underwater undulatory swimming) is utilized after dives and turns. The optimal dolphin kick has a balance between minimizing drag and maximizing thrust while also minimizing the physical exertion required of the swimmer. In this study laser scans of athletes are used to provide realistic swimmer geometries in a single anatomical pose. These are rigged and animated to closely match side-on video footage. Smoothed Particle Hydrodynamics (SPH) fluid simulations are performed to evaluate variants of this swimming stroke technique. This computational approach provides full temporal and spatial information about the flow moving around the deforming swimmer model. The effects of changes in ankle flexibility and stroke frequency are investigated through a parametric study. The results suggest that the net streamwise force on the swimmer is relatively insensitive to ankle flexibility but is strongly dependent on kick frequency.

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    • "Because of its mesh-free formation, SPH is particularly well suited to systems with moving and deforming boundaries, which is a key requirement when modelling biomechanical systems. Models of swimming and platform diving (Cohen et al., 2012; Cleary et al., 2013; Harrison et al., 2012) have comprised athlete-specific representations of body shape and movements to understand the relationship between technique, performance and injury in elite sport. Geometric risk factors for carotid artery disease have been assessed under pulsatile flow conditions using real patient vasculature (Sinnott et al., 2014). "
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    ABSTRACT: Abstract Food digestion involves the flow of material and its transformation from entry into the mouth, during passage along the gastrointestinal tract, to its eventual exit from the body. The range of food materials and their complex structures and the range of processes that are used by the human body to liberate nutrients for absorption are varied and complex. Their effectiveness is critical to human nutrition and health. An understanding of the operation of these processes can be improved substantially using advanced computational models. The complexity of this system presents many challenges for such modelling to be realistic and effective. This chapter describes the nature of these challenges and the current status of such modelling.
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    • "In the literature, there is no consensus on the influence of flexibility on swimming results. Although some studies did find a relationship between joint flexibility and swimming performance (Jagomägi & Jürimäe, 2005; Cohen et al., 2012; Kippenhan, 2002; McCullough et al., 2009; Sugimoto et al., 2008), others could not confirm this (Maglischo, 1992). The velocity of a swimmer is determined by biomechanical and bioenergetics factors. "
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    ABSTRACT: a b s t r a c t The velocity of a swimmer is determined by biomechanical and bioenergetics factors. However, little is known about the effect of ankle flexibility on dolphin kick performance. Next to this, scientific evidence is lacking concerning the influence of ankle muscle strength. Therefore, the aim of this study was to investigate the effect of ankle flexibility and muscle strength on dolphin kick performance in competitive swimmers. Ankle range of motion (ROM) and ankle muscle strength were measured in 26 healthy competitive swimmers. The effect of both was assessed on the swimmer's velocity and lower extremity joint angles during three maximal dolphin kick trials. Additionally, the effect of a flexibility restriction by a tape on the dolphin kick performance was assessed. Correlations were calculated between the flexibility, muscle strength and dolphin kick performance and differences were investigated between the unrestricted and restricted condition. Muscle strength of dorsal flexors and internal rotators were positively significantly correlated with the velocity. Active and passive plantar flexion ROM and internal rotation ROM were not significantly correlated. A plantar flexion–internal rotation
    Full-text · Article · Jun 2014 · Human Movement Science
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    • "However, at present, there is a growing research interest in these competitive techniques (Connaboy et al., 2010; Hochstein & Blickhan, 2011; Puel et al., 2012) as they are supposed to provide a competitive edge to swimmers (Atkinson, Dickey, Dragunas, & Nolte, 2014; von Loebbecke, Mittal, Fish, et al., 2009). Several factors have been reported to affect the effectiveness of underwater undulatory swimming, including the kick frequency (Cohen et al., 2012), amplitude (Houel, Elipot, André, & Hellard, 2013), symmetry (Atkinson et al., 2014) and swimmer morphology (von Loebbecke, Mittal, Fish, et al., 2009). Distances traveled with underwater movements have been found relevant to the starting and turning (Blanksby, Elliott, McElroy, & Simpson, 1998; Tourny-Chollet, Chollet, Hogie, & Papparodopoulos, 2002) competitive performances. "
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    ABSTRACT: The aim of this study was to investigate the effects of different swimming race constraints on the evolution of turn parameters. One hundred and fifty-eight national and regional level 200-m (meters) male swimming performances were video-analyzed using the individualized-distance model in the Open Comunidad de Madrid tournament. Turn (p<.001, ES=0.36) and underwater distances (p<.001, ES=0.38) as well as turn velocity (p<.001, ES=0.69) significantly dropped throughout the race, although stroke velocity and underwater velocity were maintained in the last lap of the race (p>.05). Higher expertise swimmers obtained faster average velocities and longer distances in all the turn phases (p<.001, ES=0.59), except the approach distance. In addition, national level swimmers showed the ability to maintain most of the turn parameters throughout the race, which assisted them in improving average velocity at the end of races. Therefore, the variations in the turning movements of a swimming race were expertise-related and focused on optimizing average velocity. Turning skills should be included in the swimming race action plan.
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