An Electromyographic Study on Development of Kicking Pattern in Children

本研究的目的是探讨儿童踢球的发展过程。对11名年龄从1岁8个月到5岁的儿童进行了为期5年的纵向记录，并对另外55名受试者进行了横断面记录。此外，还通过一种特殊的电子设备测量了另外580名研究对象（包括1至13岁的儿童、成年人和足球运动员）的球速。球的速度随着年龄的增长而增加，男孩从1岁的1.86m/秒增加到13岁的18.29m/秒，女孩从13岁的12.90m/秒。1岁和2岁的儿童在撞击前表现出股直肌、股内侧肌和腹直肌的电活动非常弱。3 ~ 4岁时，蹬腿向前摆动时，股内侧肌有较强的放电，但接触前的放电较接触后弱。这表明孩子们不能有效地利用膝关节伸展进行踢腿。在5 ~ 6岁阶段，腿部摆动的总弧度显著增加，手臂出现代偿性运动。5)在踢腿向前摆动时，腹直肌表现出强烈的爆发力。7 ~ 8岁时，股内侧肌的强烈放电由接触球后向接触球前转移(6)。超过10岁，男孩的膝盖、臀部、躯干和肩部肌肉的放电模式和踢腿形式几乎与成人相同。然而，就肌肉活动而言，人们无法识别踝关节的固定。从以上结果来看，学习踢球的最佳时间可能是9 ~ 13岁，此时儿童的身体平衡和球速接近成人水平。

The purpose of this study was to examine the developmental process of the ball-kick in children. EMG activity and Form were longitudinally recorded throughout periods of over five years for eleven children ranging in age from 1 year 8 months to 5 years, and cross-sectionally recorded for anothe 55 subjects.In addition, ball speed for another 580 subjects, including children 1 to 13 years old, adults, and soccer-players, was measured through a special electrical device.1). Ball speed increased with the age in both sex, from 1.86m/sec for 1 year to 18.29m/sec for 13 year old boys, and to 12.90m/sec for 13 year old girls.2). One and two year old children showed very weak electrical activity of the rectus femoris, vastus medialis, and rectus abdominis muscles throughout the period before impact.3). At the stage of 3 to 4 years of age, the vastus medialis showed a strong discharge during the forward swing of the kicking leg, but the discharge was weaker before contact than after. This indicated that the children were not able to use the knee extension effectively for kicking.4). At the stage of 5 to 6 years of age, the total arc of leg-swing increased significantly and a compensatory arm movement appeared. The rectus abdominis showed a strong burst during the forward swing of the kicking leg.5). At the stage of 7 to 8 years of age, the strong discharge of the vastus medialis shifted from the period after ball contact to before.6). Beyond 10 years of age, the discharge pattern of knee, hip, trunk, and shoulder muscles, and kicking form showed almost the same pattern in boys as in adults. However, one could not recognize fixation of the ankle joint in terms of muscle activity.7). From the above results, the optimum time to learn the kick might be existed between 9 and 13 years of age, when children approach the adult level of body balance and of ball speed.