原因一：跑时全脚掌着地跑是单脚前脚掌着地支撑与腾空相互交替的周期性运动。教学时，许多教师往往忽视提醒学生跑时前脚掌着地支撑腾空的动作要点，大多数学生下意识地认为跑是走的一种加速运动。练习时采用全脚掌着地支撑，后蹬用力不够，身体重心前移不到位，脚后跟着地次 One reason: running the whole foot palm to run is a single foot before the foot support and vacate the cyclical movement alternately. When teaching, many teachers often neglect reminding students to run when the front of the ground to support the emptiness of the action points, most students subconsciously think that running is an accelerated movement. Foot exercises used to support the whole foot, pedal force is not enough, the body center of gravity forward is not in place, heel with the ground