摘要
In soccer, the bicycle kick has provided view- ers moments of breathtaking spectacle that seem virtuosic in scope. The novelty of such moments is underscored by the rarity with which players have performed this complex skill during national or international tournaments. The rarity of these occurrences is both a product of perceptions that it is a high-risk, low return skill and by the fact that there is a dearth of scientific research on the biomechanics of the technique. Two genera can be discerned based on starting position： 1） back-facing the goal, and 2） side-fac- ing the goal. The current study, using 3D motion capture technology and full-body biomechanical modeling, identi- fies elements that govern entrainment of the technique by examining jumping, kicking and falling phases of the skill execution. Motor sequencing during the first two phases can be characterized by analyzing the following pa- rameters： 1） angle between the player＇s thighs （humerus bones） upon take-off, 2） the whip-like control of the kicking leg, 3） timing between ball motion and joint co- ordination and, for the side-facing bicycle kick, 4） rotation of the player＇s trunk during the jumping phase. Dispersion of energy during falling after the kick is accomplished by sharing the load using a sequence of partial landings. Collectively, this information could help entrainment of the skill. Virtuosic in appearance, more frequent use of the kick can only enhance the excitement of the game.
足球"倒挂金钩"技术给观众提供了令人惊叹的奇观瞬间,但少有球员在国家及国际级比赛中完成此精湛技艺.这一"魔术"般技能的稀有原因是:(1)高风险、低回报,(2)没有科学的方法来量化和揭秘该技能的动作要素.目前观察到背对球门和侧对球门2种踢法.我们用三维动作捕捉技术和人体运动生物力学模型对其的量化,结果表明下列要素起到决定性作用:(1)髋关节的柔软性,(2)踢球腿的"鞭抽"控制,(3)时控;此外,侧对球门的踢法还有另一要素:起跳前的躯干逆向旋转将增大踢球的动量.完成踢球后的落地是训练时的心理障碍.分散吸收落地冲量可避免受伤.让更多的球员掌握"倒挂金钩"技术将进一步提升足球的魅力.
基金
supported by National Sciences and Engineering Research Council of Canada
