As your left leg slides back your right arm should swing forward.

当你的左脚向后滑时，你的右手臂就得向前摆。

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Swinging leg should actively swing forward after taking off the board to lower horizontal speed loss and improve the jumping speed.

摆动腿蹬离地面后积极前摆对加快起跳腿的下压着板、减少水平速度损失、获得较大的腾起初速度有利。

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On the first day of school, Socrates told his students, "Today, we'll only learn one thing. That is to swing your arm forward and backward."

在开学的第一天，苏格拉底告诉他的学生：“今天，我们只学一件事情。那就是前后摆动你的手臂。”

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Their long, heavy arms, good for hanging from branches, act as pendulums to swing their weight forward as they uncoil from the crouch.

BBC: Gibbons' extraordinary jumps 'down to technique'

Seth started to give chase, but another guy stepped forward and took a swing at his jaw.

FORBES: Magazine Article

Plans have been put forward to replace the floating swing bridge with an automated moving pontoon.

BBC: New Broads river crossing planned