Oliver doesn't move much in his sleep. For ages he would stay exactly where he way put down. Then we had a rough patch where he was waking frequently and we figured out it was the sleeping bag, he wanted to sleep on his tummy but couldn't roll over in it. So we got rid of it and he is now a tummy sleeper. Once he is asleep he still doesn't move at all, but he will wriggle around a bit to get comfy before falling into a deep sleep, and he does wriggle on waking. He is very active when awake so I don't worry.