> > That happens to me very frequently. At least once every two nights. Last night was the first time it happened to my wife. We were dozing off and all of the sudden, her leg jerked. That never happens to her. That's my thing!
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> Happens to nearly everybody, nearly every the time one descends into REM sleep. Leen even studied it in one of her biology-related courses in college. Basically, you twitch or jerk when you fall into REM, and sometimes, depending on the circumstances, it's enough to wake you right back up. If you've ever watched someone go to sleep right next to you, usually there will be *some* kind of quiver, severe or not. I think I vaguely remember that being overtired makes it more likely that it'll be severe enough to wake you right back up, but I'm not positive about that. That seems likely to be true in my case, at least.

I tend to get annoyed when that happens. I'm almost fully asleep when my whole body suddenly jerks. This isn't just a leg thing, the way Faux Pas and Grishny described. No, it's my whole body. It often happens when I'm having a flying or falling dream. I'm about to land when that twitch-jerk-spasm thing happens. It startles me awake, I get mildly irritated, and then I drift off to sleep again.

Ell"Heavy sleeper 90% of the time"myruh