Falling off the Curb sensation

Is there a medical or scientific explanation for why when people are lying in bed they will suddenly feel like their foot slipped off the curb?

I read a thread in the archive about suddenly jerking awake but couldnt tell if that was talking about the same thing.

I’m pretty sure it’s the same thing. What I never get is how does my brain think up this scenario so fast because I will just be drifiting off then suddenly I’m walking, and boom, I fall off the curb. It seems impossible to imagine that I start to dream about walking on a sidewalk in anticipation of needing an explanation for jerking awake in a few seconds. I guess at the exact second my body falls off the curb my mind kind of goes back and says, “oh you must have been on a sidewalk” but it sure is tricking me because I could swear every time that I was having a nice dream of walking down the street when I missed a step.

The more I think about it the more freaky it is. Does everyone fall off the curb? Or do some people maybe step into a gopher hole?

For me it’s stairs sometimes. But never a long fall (like a whole flight of stairs), always a short one (just the last step or two).

For a fraction of a second, it’s really a frightening and bewildering feeling.

Never a curb for me; usually a small bridge, or some stairs.

I get the curb sometimes, other times it is like someone jerked the bed out from under me.

The master speaketh.

BTW, I love the ads this thread has generated.