Dream FAQ Dictionary: What is a myoclonic jerk?
What is a myoclonic jerk? This term denotes a common experience with sudden contractions of thebig body muscles while falling asleep. This mostly causes a feeling ofstumbling, falling or similar and subsequently waking up again. The exact cause is not known, it probably is some disturbance in thebrain’s functions in the first stage of sleep. Surely it is common,and does not cause serious problems unless it stops you from sleeping(but then you have general sleeping problems as well). [From: Corey Thompson