arm movement during naps

randcbaby

My son sleeps great at night in the Rock n Play and naps unswaddled in his crib. I watch him napping on the monitor, and he tends to fall asleep with his arms raised in the air. As they drop down toward the mattress, he'll jerk them back up. He doesn't wake up when he does this except when he jerks them and they accidentally knock out his pacifier. If his pacifier falls out on its own, he's fine.

Is there anything I can do to help him? Is this something he'll just outgrow of? When he does wake up, I can often just go back in, re-insert his paci, and he'll go right back to sleep. I just feel like he can't be getting as good of a nap if he is waking up once or twice in the middle. (Plus, it would be nice not to have to go back in to his room!)

 Thanks in advance!