An Electromyographic Study on Development of Kicking Pattern in Children

本研究旨在探讨儿童踢球动作的发展过程。对11名1岁8个月~ 5岁儿童的肌电活动和形态进行了5年以上的纵向记录，对另外55名儿童进行了横断面记录，并对另外580名儿童（1 ~ 13岁儿童、成人和足球运动员）的球速进行了专门的电子测量。球速随年龄的增长而增加，从1岁时的1.86米/秒增加到13岁时的18.29米/秒，13岁时的12.90米/秒。1岁和2岁的儿童在撞击前的整个期间表现出股直肌、股内侧肌和腹直肌的非常弱的电活动。在3 ~ 4岁阶段，股内侧肌在蹬腿前摆时有较强的放电，但接触前放电较接触后弱。这表明孩子们不能有效地使用膝盖伸展来踢球。在5 ~ 6岁阶段，摆动腿总弧度明显增大，出现了代偿性的手臂运动。腹直肌在踢腿向前摆动时表现出强烈的爆发。7 ~ 8岁时，股内侧肌的强放电由触球后过渡到触球前。10岁以后，膝、髋、躯干和肩部肌肉的放电模式以及踢腿形式在男孩中显示出与成人几乎相同的模式。然而，人们不能从肌肉活动方面认识到踝关节的固定。从以上结果来看，儿童学习踢球的最佳时间可能在9 ~ 13岁之间，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.