This is a really simple but dirty trick to play on somebody in a game of Apocalypse World. In the first session, you are usually asking the players to describe their characters and in part of this it is assumed that the player will describe what their character looks like. The playbooks give some hints as to how to describe one's appearance, but often players won't go beyond the basic summaries provided and it's the MC's job to help them flesh those bits out.
Your Driver has utility wear? How would you describe it? Is it like a jumpsuit or overalls or something more archaic or more advanced?
Eventually, everybody around the table will get used to your questions about their appearance. They'll be thinking more about the overall look their character has, and you can start asking "What kind of shoes are you wearing?" Somebody might say sandals, somebody might say nothing, somebody might say sneakers, but you're looking for somebody who says boots or steel-toed shoes. The more protective the player describes the shoes, the better.
In the very first fight this character is in and they miss a roll, simply declare "One of your boots rips, the stitching has ripped and the sole is loose from the leather around your toes." Now, every time that character misses a roll you can escalate the harm that is happening to their feet. The shoes get wet mud stuck inside, and between the character toes. Blood and oil and dirt of all kinds will spill into the hole, trapped between the toes and the fabric.
Now you can write this as a countdown clock, or have one prepared already:
3 o'clock: foot swells, skin wrinkled
6 o'clock: rash, foot itches badly
9 o'clock: painful swelling, hard to run
10 o'clock: can't run
11 o'clock: can't walk
Midnight: foot's a goner
It's a pretty simple escalation, and it also has a simple solution: buy new boots (if you can find them) or simply throw away the broken boots. In Apocalypse World, or any post-apocalyptic world, every possible thing can break and eventually cause serious problems if they're not taken care of. I like to use simple things to blindside players because they are often focusing on he crazy maniacs of the world and overlooking these things.