Exercise and Sport Science, Faculty of Medicine and Health, The University of Sydney, Sydney, Australia.
School of Sport, Faculty of Life and Health Sciences, Ulster University, Jordanstown, Northern Ireland.
Sports Biomech. 2023 Aug;22(8):982-996. doi: 10.1080/14763141.2020.1773915. Epub 2020 Jul 7.
The aim of this study was to determine the influence of torso morphology on maximum instantaneous hydrodynamic resistance in front crawl swimming. Outlines of the torso in the frontal and anteroposterior planes were calculated from photographic images to determine continuous form gradients (m/m) for the anterior, posterior and lateral aspects of the torso. Torso cross-sectional areas at each vertical sample (0.001 m) were used to calculate maximal rate of change in cross-sectional area (m/m) in the chest-waist and waist-hip segments. During the non-propulsive hand phase in middle-long distance front crawl, kicking propulsion is negligible and therefore the net force is equal to the drag. Drag coefficients were calculated at the instant of maximum horizontal deceleration of centre of mass during the non-propulsive hand phase of 400 m pace front crawl. Maximal rate of change in cross-sectional area ( = 0.44, = 0.014) and posterior form gradient ( = 0.50, = 0.006) of the waist-hip torso segment had moderate positive correlations with the maximal drag coefficient. A regression model including these variables explained 41% of the variance ( = 0.001). Indentation at the waist and curvature of the buttocks may result in greater drag force and influence swimming performance.
本研究旨在确定躯干形态对自由泳中最大瞬时水动力阻力的影响。从前视和额状面的照片中计算出躯干轮廓，以确定躯干前、后和侧面的连续形态梯度（m/m）。在每个垂直样本（0.001 m）处测量躯干横截面积，以计算胸部-腰部和腰部-臀部段的横截面积最大变化率（m/m）。在中长距离自由泳的非推进手阶段，踢腿推进可以忽略不计，因此合力等于阻力。在 400 米自由泳的非推进手阶段，在质心最大水平减速瞬间计算阻力系数。腰部-臀部躯干段的横截面积最大变化率（ = 0.44， = 0.014）和后形态梯度（ = 0.50， = 0.006）与最大阻力系数呈中度正相关。包括这些变量的回归模型解释了 41%的方差（ = 0.001）。腰部凹陷和臀部曲线可能会导致更大的阻力，并影响游泳表现。
