这个短语的字面解释是“向后弯腰”，这是什么意思呢？请看对话：

    A: You didn’t speak a word with John at the party. I thought you were friends.

    B: We are friends no more. I bent over backwards to help him, and he never ever thanked me.

    Note: Unless you are extremely flexible, actually bending over backwards is quite a feat. It’s not at all surprising that the origin of the idiom “bend over backwards” is in gymnastics. The term was used as early as A.D. 920 to compare the athletic act of back bending with an expenditure of effort to ensure that something went as planned. This idiom is a figurative way to say “working very hard to accomplish something for someone.” We often use it in the structure to “bend over backwards (to do something) (for someone).”