What is the origin of the idiom "cover one's back" and when to use it?

The idiom "cover one's back" is related to the idea of providing protection for oneself, particularly in situations where one may face criticism, blame, or consequences. It likely evolved from the more common phrase "cover one's ass" (CYA), which has its origins in American English in the mid-20th century and is often used in a similar sense to describe actions taken by individuals or organizations to safeguard themselves from potential criticism, blame, or adverse consequences.