“Step on a crack, and break your mother’s back.”
My informant first heard this rhyme while he was walking home with his friend Amy after school. He was a seventh or eighth grader in middle school that was located in Downey, CA. To pass the time away and to forget about the fatigue from walking in the blazing sun with their heavy backpacks, they began to play a game. The game started when Amy noticed that David kept stepping on the cracks of the sidewalk. She chanted, “Step on a crack, and break your mother’s back.” They skipped over the lines all the way home. If one of them would accidentally step on a line, the other would shrug and say, “Oh well. Your mother just broke her back.”
I have heard this rhyme myself many times from elementary school to middle school. There is another variation: “Step on a line and break your mother’s spine.” It would be a fun game to play while walking home from school or when we played hopscotch, a game in which you would have to jump over boxes and not touch the lines, someone would always chant this rhyme. I believe the rhyme stemmed from how “crack” and “back” rhymes and since the point of the game was to not step on the crack, kids would warn that in doing so you would break your mother’s back. That would keep you within the rules of the game of not stepping on the crack.