What sleeps start

Have you ever experience drifting of to sleep and then suddenly having a sensation of falling and jerking awake,? what you experience is called a sleep start, a sudden and oftentimes violent jerking of the body. usually at the arms, and legs. that occurs as you falling a sleep. sleep starts goes by the names hypnotic ( or pedagogic jerk) and sleep jerk. it is known why it occurs?, but there are two theories about it.

1. is that starts are natural sleep in or, by product of body muscular.
2. is that as we fall asleep there is a point at which muscles completely relax to our brain interprets our relaxation as a sign of falling down.