TMZ.com

Medics had to help Post off the stage because he was so bad, and the fans didn't know if they should pack it in or wait.

He was performing at the Enterprise Center when it happened.

Post walked down a ramp onto the floor of the arena. He used to lower his guitar on the floor and it hadn't been covered up.

He fell on the floor. One of the man's legs was shaking uncontrollably, according to an eye witness. As he left the stage, medics rushed in and surrounded him.

He asked fans to give him a few minutes to collect himself, but everyone was worried and doubtful he'd return.

Post came back 15 minutes later to perform "Rockstar" and "Cooped Up". Even though he was in pain, Post was determined to keep going.

Post apologized to the crowd and said there was a big-ass hole in the stage. He signed a few autographs after the show.

He's going to continue his tour in Columbus Sunday.