Involuntary muscle movements have never been a general problem, although it does happen on occaision.

For example, I was trying to sleep with music on last night and whenever I was drifting off my leg would jerk. It would have been kind of funny if I wasn't so tired. As it was it was just annoying.

I find I quite often get some sort of cramp in my legs and feet while I'm trying to get to sleep, which poses a simelar problem. I have to rearrange my legs and then start relaxing over again.