Breaststroke swimmers moderate internal work increases toward the highest stroke frequencies

JOURNAL OF BIOMECHANICS

卷:48

Article

Lauer, Jessy^1,2  Olstad, Bjorn Harald¹  Minetti, Alberto Enrico³  Kjendlie, Per-Ludvik¹  Rouard, Annie Helene² 

[1] Norwegian Sch Sport Sci, Dept Phys Performance, Oslo, Norway

[2] Univ Savoy, Lab Exercise Physiol EA4338, Le Bourget Du Lac, France

[3] Univ Milan, Dept Pathophysiol & Transplantat, Milan, Italy

关键词: Mechanical energy;    Swimming;    Predictive equation;    Quadrupedal locomotion;   

DOI  :  10.1016/j.jbiomech.2015.07.033

来源: Elsevier

【 摘 要 】

A model to predict the mechanical internal work of breaststroke swimming was designed. It allowed us to explore the frequency-internal work relationship in aquatic locomotion. Its accuracy was checked against internal work values calculated from kinematic sequences of eight participants swimming at three different self-chosen paces. Model predictions closely matched experimental data (0.58 +/- 0.07 vs 0.59 +/- 0.05 J kg(-1) m(-1); t(23)=-0.30, P=0.77), which was reflected in a slope of the major axis regression between measured and predicted total internal work whose 95% confidence intervals included the value of 1 (beta=0.84, [0.61, 1.07], N=24). The model shed light on swimmers ability to moderate the increase in internal work at high stroke frequencies. This strategy of energy minimization has never been observed before in humans, but is present in quadrupedal and octopedal animal locomotion. This was achieved through a reduced angular excursion of the heaviest segments (7.2 +/- 2.9 degrees and 3.6 +/- 1.5 degrees for the thighs and trunk, respectively, P< 0.05) in favor of the lightest ones (8.8 +/- 23 and 7.4 +/- 1.0 degrees for the shanks and forearms, respectively, P< 0.05). A deeper understanding of the energy flow between the body segments and the environment is required to ascertain the possible dependency between internal and external work. This will prove essential to better understand swimming mechanical cost determinants and power generation in aquatic movements. (C) 2015 Elsevier Ltd. All rights reserved.

【 授权许可】

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