What the hell is that weird feeling of “fallin” or “tripping” just as I’m going to sleep? Sometimes I think I jump a foot off the bed. Anyone know what this is?
Nickrz, this is one time I think Uncle Cece gave the letter writer short shrift, turning the subject to sleep apnea instead of talking more about hypnagogic myoclonus.
Dalou, the following is just my recall of what I have read/heard on the subject elsewhere, so be advised.
Hypnagogic myoclonus is what happens when, supposedly, your mind/brain ‘disconnects’ from the voluntary nervous system and it’s control of musculature (myoclonus) at the onset of full sleep (hypnogogia). The theory I have read is that this was an evolutionary adaptation that prevents you from ‘acting out’ your dreams during your sleep. Naturally, in a waking situation, the sudden loss of voluntary muscle control would be an occasion for panic; the part of your mind that’s still somewhat ‘awake’ reacts to this with that ‘missing a stair in the dark’ sensation (as I think of it) that brings you bolt upright with a cold sweat.
Unless it happens every time you fall to sleep, or it happens often enough that it really bothers you, I wouldn’t – uh – let it bother me. If you’re not to the point of seeing a doctor, I’d recommend taking an aspirin tablet (or two, depending on your weight and gastric sensitivity to aspirin, et al an hour or so before bed.
Actually, the real reason is that you’re actually levitating about a foot off the bed as you fall asleep, but then you lose your psychic concentration and gravity returns.
But you already knew that, I’m sure. 
This is often a result of trying to sleep while standing up. The accepted cure for this condition is to find horizontal surface upon which to lie down before going to sleep.
The only place I ever “tripped” to sleep was at a 1982 Dead show.
~Konrad~, you darling boy, you have done it again! Your wit and humor never cease to amaze me! You are just so, so FUNNY!
But, if I could point out one itsy-bitsy, teensy-weensy mistake - there should be an ‘a’ between ‘find’ and ‘horizontal’. Otherwise it reads like pidgen Japanese.
Toodle-oo, ~Konnie~!
The woods would be very silent if no birds sang there except those that sang best. - Henry Van Dyke
Cecil said hypnagogic myoclonus “…basically consists of sudden full-body twitches, and often it’s preceded by a sensation of falling. It’s not clear why myoclonus occurs, but it’s nothing to worry about.” but if the OP would rather listen to other blather and take aspirin for it, that’s his prerogative.