Literal Translation
To fold oneself in four
Actual Meaning
To bend over backwards
Etymology
Dating back to the 17th century, this expression was used differently in the past. In fact, people used to say “se mettre en quatre quartiers” (similar to “se décarcasser”) or “se couper en quatre”, which is a more explicit image.
This expression is generally used to mean doing someone a favour or accomplishing a difficult task. Four people are much more efficient and productive than one.
If everyone who wanted to help others had a magic formula to create three clones, they would easily be able to bend over backwards.
Furthermore, in “se plier en quatre”, it is easy to imagine trying to bend one’s body into four pieces, which quickly evokes the difficulty and effort required to achieve something. In short, this expression is mainly used to signify an effort made towards someone.