A Basic Study on the Optimum Time to Learn the Crouching Start, Overhand Throwing, and Walking on Stilts - Effectiveness of the Practice in Different Ages -

我们做了三项调查，从练习效率的角度，阐明什么时候是孩子们学习短跑、网球过手投掷和踩高跷开始下蹲的最佳时机。结果表明，下蹲开始变得有效，与其说是因为肌肉力量的增加，不如说是因为肌肉力量的使用方式。也就是说，肌肉以一种新的方式被激活，从而有效地开始蹲伏。我们让132名从小学五年级到初中的男孩在七天的时间里每天练习20分钟的蹲姿开始。这种做法在初一和初二学生中效果最好。我们让278名从小学一年级到初中的孩子进行为期四周(每周4天)的投掷网球练习。EFOF对投掷能力的练习在7岁和8岁的男孩中最好，在8到10岁的女孩中最好。这与投掷距离发展最快的年龄范围很好地对应。我们让252名从幼儿园到小学的孩子在四天的时间里每天练习踩高跷20分钟。从6岁到9岁，练习的数量随着年龄的增长而减少，在这些练习中，他们能够在十步以上的高跷上行走。通过这三项研究，我们得出结论：男童在13岁和14岁左右开始学蹲，男童在7岁和8岁左右，女生在8岁，9岁和10岁左右是学习俯卧撑的最佳时机，无论男女，踩高跷都是在9岁左右。

We did three investigations to clarify when would be the best time for children to learn the crouching start in sprinting, over-hand throwing with a tennisball, and walking on stilts, from the view point of effctiveness of practice. The results suggested that the crouching start became effective not so much because of increased muscle strength as because of manner in which the muscle strength was used. That is, the muscle were activated in a new way for an effective crouching start. We had 132 boys from fifth grade in elementary school through junior high school practice the crouching start 20 minutes a day over a seven day period. the practice was most effective in the first and second year junior high school students. We had 278 children from first grade in elementary school through junior high school practice the over-hand throwing a tennisball for four weeks (4 days per week). The efof practice on throwing ability was greatest in boys at seven and eight years of age, and in girls at eight to ten years of age. this corresponded well with the age ranges at which throwing distance was developing most rapidly. We had 252 children from kindergarten through elementary school practice the walking on stilts 20 minutes a day over a four day period. The number of practice, in which they become able to walk on stilts more than ten steps, decreased with age from six to nine years. From these three studies, we conclude that the best time to learn the crouching start is at about the 13 and 14 years for boy, the over-hand throwing is at about 7 and 8 years for boy, and 8,9 and 10 years for girls, and the walking on stilts is at about 9 years for both sexs.