I don't know why, but when I try and go to sleep, I will twitch (eg: my body rapidly does a twitch when trying to sleep (like my whole body,or just one part of me like my neck,arm(s) or leg(s)) I've never had this in the past, but this has been going on for a long matter of months and it's really bugging me now and I can't controll it. I used to smoke cannabis on an occasion in the past, but not touched it since (I keep thinking thats the cause, but I'm not sure)No matter how I'm feeling, happy,relaxed,sad or stressed, I still get these twitches and I have no idea why.
I had something similar happen to me during the day and at night and my doc told me i was expiriencing the aftershock for an overworked body. I would suggest stretches before bed and after you wake up it helps me. hope it helps you too