What is the origin of the idiom "when push comes to shove" and when to use it?

The phrase "when push comes to shove" is an idiom used to describe a situation when things become difficult or critical, often requiring decisive action or revealing one's true intentions. The origin of this phrase is not precisely documented, but it likely draws from the idea that when external pressure is applied (a push), individuals may be compelled to act or make a decision (shove).