"Falls over backwards" is an idiom that refers to someone making an extraordinary effort or going out of their way to please or impress someone. There are many synonyms for this expression, including bend over backwards, go the extra mile, go out of one's way, make a major effort, and spare no effort. Each of these phrases implies that someone is willing to work very hard or do something out of the ordinary to achieve a goal or make someone happy. These expressions are often used to describe people who are very dedicated, motivated, or generous, and they can be used in a variety of contexts, from personal relationships to work situations.