Your mother should’ve taught you, “There’s a right way to do everything.”
That includes falling down a flight of stairs.
Here’s how stunt men do it. The difference is they expect to fall down the stairs, they’re ready for it, and they’ve practiced a lot. We just slip and fall.
But heck, it’s just like I learned in judo school, many years ago: tuck your chin against your chest, protect your head, and don’t stick your arms out. After a few thousand practice falls, you’ll have it down pat.
Then you can practice falling down the stairs.