where is the off switch?!?!?!

Sam came with us to the wing night we attend each month with several other families. He played with the big kids andn ot so big kids (my friends grand daughter was there who is 2 and adorable)- he was wound up- but not in a bad mood, just hyper. He didnt fall asleep until nearly 945....i expected him to be asleep until nearly 8am. Then what to my surprise did i hear at 3:14am?! Little Sam feet pounding on the floors...roaming the top floor...just running around...not screaming and sad, not confused- on a mission. He was up and needed us to know he felt he should stay up. I tried to get him back to sleep- gave up after 45 min, left him in the big bed with John, and came down stairs....he slept maybe an hour more, then came trotting down the stairs. I tried to lay down with him from 6:15am until after 700am ...no avail. I even drove him around a bit after we dropped off gabe...let him run around the house and have an early lunch...tried for a nap at 1030- he slept like 45 minutes and was up again....he is still awake...would not take a later nap at 4pm either- we tried to fall asleep for over half an hour. I have no clue what is going on, but he has had less than 6 hours of sleep in the last day and he usually has 10 or 11.....yikes
Tomorrow we go to see a peds ortho specialist for his legs!