Biomechanical analysis for how to attain proficiency in ball impact technique in soccer

快速踢球是足球运动员的基本能力。通过日常训练，球员们学会了如何有效地将脚和腿的动量传递给球。本研究的目的是用横截面法探讨儿童到青少年运动员脚背踢中球的冲击特性的变化。51名8至24岁的熟练（包括职业）足球运动员参加了比赛。用2台超高速摄像机以2000 fps的速度捕捉最大脚背踢球冲击过程中小腿、足部和球的运动。检测足部三维角运动，计算球脚速度比（BFVR）作为球冲击效率的指标。为了量化碰撞所传递的质量，从动量守恒方程中估计了踢肢的有效击打质量。球前脚速度、球速度、BFVR随年龄有系统的增加。在大多数试验中，无论年龄大小，在球撞击过程中，足部的受力更多地表现为足底屈曲、外展和外翻。与Asami和Nolte（1983）认为足部刚度是良好足球冲击的关键因素相反，这些被动的足部角位移与BFVR没有关系。有效撞击质量与体重呈显著正相关（r=0）。89)，足部质量(r=0。91)， BFVR(r=0。88)。脚和鞋的质量之和等于84。0±9。lees和Nolan（1998）还推测，如果踝关节在球的冲击下变得更加僵硬，那么通过在脚上增加一部分小腿质量，可以增加有效的打击质量。然而，我们的研究结果表明，如果脚以适当的位置击球(如。（E.围绕质心），球的撞击很可能被认为是穿鞋的脚和球之间的碰撞。足球运动员的体型对球的冲击效率有很大的影响。因此，由于脚的质量小，即使年轻球员的踢球技术很好，在有效地踢球方面也有一些劣势。少

To kick the ball faster is essential ability for soccer players. Through daily training, the players learn how to impart the foot and leg momentum into the ball effectively. The purpose of this study was to investigate the change of ball impact characteristics in instep kicking from childhood to adolescent players by the cross-sectional method.Fifty one skilled(including professional) soccer players from 8 to 24 years old participated. The shank, foot and ball motions during ball impact of maximal instep kicking were captured by two ultra-high-speed video cameras at 2000 fps. 3D foot angular motion was detected, and the ball-foot velocity ratio(BFVR) was calculated as the index of ball impact efficiency. To quantify how much the mass was imparted for the collision, effective striking mass of kicking limb was estimated from the equation of momentum conservation.Foot velocity before ball impact, ball velocity, and BFVR increased systematically with age. In most trials, the foot was force … More d into plantar flexion, abduction and eversion during ball impact regardless of age. In contrast to Asami and Nolte(1983) who suggested that the rigidity of the foot is critical factor for good foot-ball impact, these passive foot angular displacements have no relationship to BFVR. The effective striking mass was strongly correlated with their body mass(r=0. 89), foot mass(r=0. 91), and BFVR(r=0. 88). The sum of the mass of the foot and shoe corresponded to 84. 0±9. 6% of the striking massLees and Nolan(1998) also speculated that if the ankle becomes more rigid at ball impact, the effective striking mass would increase by adding some part of the shank mass on the foot. However, our results suggested that if the foot hit the ball with appropriate position(i. e. around the centre of mass), the ball impact is most likely assumed to be a collision between the shod foot and the ball.The physical size of the soccer players has great influence on the ball impact efficiency. Therefore, due to the small mass of the foot, younger players have some disadvantage to kick the ball effectively even if their kicking technique is well skillful. Less