Institute of Health and Sport Sciences, University of Tsukuba, Tsukuba, Japan; Advanced Research Initiative for Human High Performance (ARIHHP), University of Tsukuba, Tsukuba, Japan.
School of Physical Education, Health and Sport Sciences, University of Tsukuba, Tsukuba, Japan.
Hum Mov Sci. 2024 Oct;97:103272. doi: 10.1016/j.humov.2024.103272. Epub 2024 Aug 21.
The distribution of motor errors can influence optimal motor planning (where to aim). In football instep kicking, it was shown that ball landing locations exhibit the right-up-left-down elliptical distribution in right-footed kickers and vice versa. However, this was reported as a result of mixed multiple kickers; the individual-level error distribution has been unclear. Here we show substantial inter-individual variability in error shape and error direction in the 30 kicks aimed at a target (1.7 m high, 11.0 m in front) by 27 male football players. All players exhibit right-up-left-down distributions with ellipticity (minor/major radius ratio of the 95% confidence ellipse) ranging from 0.25 to 0.77 and major axis angle ranging from 13 to 67° from the horizontal axis. The mean absolute error and the area of the 95% confidence ellipse are not significantly correlated with major axis angle (ρ ≤ 0.312) and ellipticity (|r| ≤ 0.343). By simulating shots aimed at the top-right and top-left edges of a goal with these observed ranges and normalised ellipse area, we reveal a wide range of probability of shots on goal (top-right: 2.7-fold difference, top-left: 1.5-fold difference) due to inter-individual variability in error shape and direction independent of error size. Further simulation shows that, depending on the shape-direction combination, the aiming points with the same 80% probability of shots on goal change by up to 0.3 m vertically, even for the same minimal error size. We highlight the importance for football players to consider not only accuracy/precision, but also error shape and direction to optimise motor planning.
运动误差的分布会影响到最佳的运动规划（即瞄准哪里）。在足球正脚背踢球中，研究表明右脚踢球者的球着地点呈现出右-上-左-下的椭圆形分布，反之亦然。然而，这是基于混合了多个踢球者的报告结果；个人层面的误差分布尚不清楚。在这里，我们展示了 27 名男性足球运动员在 30 次踢向目标（高 1.7 米，距离 11.0 米）的射门中，个体间的误差形状和方向存在显著差异。所有球员的着地点都呈现出右-上-左-下的椭圆形分布，其椭圆度（95%置信椭圆的短半轴与长半轴之比）在 0.25 到 0.77 之间，主半轴角度在 13 到 67°之间，与水平轴的夹角。平均绝对误差和 95%置信椭圆的面积与主半轴角度（ρ≤0.312）和椭圆度（|r|≤0.343）没有显著相关性。通过模拟以这些观察到的范围和归一化椭圆面积瞄准球门右上角和左上角的射门，我们揭示了由于个体间误差形状和方向的差异，射门命中球门的概率有很大的差异（右上角：2.7 倍差异，左上角：1.5 倍差异），而与误差大小无关。进一步的模拟表明，根据形状-方向组合，即使误差大小相同，具有相同 80%射门命中球门概率的瞄准点在垂直方向上也可能相差 0.3 米。我们强调了足球运动员不仅要考虑准确性/精度，还要考虑误差的形状和方向，以优化运动规划的重要性。
