bend over 弯腰；俯身。bend v.弯曲；使弯曲；屈服；屈从；集中于。
bend/lean over backwards竭力，尽力。

【例句】
He bent over and picked up a silver coin.
他弯腰拾起一枚银币。

I've been bending over backwards trying to help you, and this is all the thanks I get!
我一直在尽力帮助你，没想到这就是你对我的感谢！