Democritus University of Thrace, School of Physical Education and Sport Science, Department of Physical Education and Sport Science, Komotini, Greece.
Aristotle University of Thessaloniki, School of Physical Education and Sport Science, Department of Physical Education and Sports Sciences, Thessaloniki, Greece.
J Biomech. 2022 Sep;142:111255. doi: 10.1016/j.jbiomech.2022.111255. Epub 2022 Aug 10.
The aim of the current study was to compare the arm-stroke kinematics during maximal and sub-maximal breaststroke swimming using both discrete and continuous data analysis. Nine male breaststrokers swam 2 × 25 m with maximal and sub-maximal intensity and their full body 3-D kinematics were obtained using eight video cameras. The arm-stroke was divided into five phases: recovery, glide, out-sweep, in & down-sweep and in & up-sweep. The statistical treatment of selected discrete variables was conducted using t-test, while the analysis of their equivalent time series, when applicable, was conducted using Statistical Parametric Mapping. Sub-maximal trial, compared to maximal, presented lower swimming velocity, greater stroke length and less stroke rate. Moreover, the absolute and relative duration of the glide phase was longer, while the relative duration of all the other phases was shorter. The resultant hand velocity during the arm recovery was slower, as well as the hand velocity time series in the transverse and longitudinal axis which were slower from ∼ 45 % to ∼ 60 % and from ∼ 5 % to ∼ 15 % of the stroke cycle, respectively. Both discrete and continuous data analysis revealed that the main discriminating factor between the two conditions concerns to the adjustment of the glide and the recovery phase and consequently the continuation of the propulsive movements.
本研究旨在比较使用离散和连续数据分析在最大和次最大强度下的蛙泳臂部划水运动学。9 名男性蛙泳运动员以最大和次最大强度游 2×25 米，并使用 8 台摄像机获取其全身 3D 运动学数据。将臂部划水动作分为五个阶段：恢复、滑行、外扫、内扫和下扫、内扫和上扫。选择离散变量的统计处理采用 t 检验，而当其等效时间序列可分析时，则采用统计参数映射进行分析。与最大强度相比，次最大强度试验的游泳速度较低，划水距离较长，划水频率较低。此外，滑行阶段的绝对和相对持续时间较长，而所有其他阶段的相对持续时间较短。手臂恢复过程中的手速较慢，横向和纵向轴的手速时间序列也较慢，分别约为 45%到 60%和约 5%到 15%的划水周期。离散和连续数据分析均表明，两种条件之间的主要区别因素与滑行和恢复阶段的调整有关，进而与推进运动的连续性有关。
