Baby reflex

Does anyone else's baby have weird reflexes like he's falling it looks like he's having a siezure could it be that he's so used to small sleeping bassinets and rock and play he sleeps in those more and in the swing more than his crib and when I put him in his crib he wakes up out of his sleep so much bcs he feels like there's a lot more space like he's falling how do I prevent this from happening