PITTSBURGH -

Pennsylvania Gov. Tom Corbett is recovering from back surgery at Allegheny General Hospital in Pittsburgh.

The surgery the governor went through is a very common procedure to treat spinal stenosis, which doctors explain results in pain when you walk because your nerves going through your spine are under pressure.

"The yellow represents where the nerves go through usually that's the size of a quarter unfortunately his canal was the size of a pencil," explained Dr. Mark Fye, director of orthopedic spine trauma.

Fye was one of the doctors who performed surgery on Corbett, 61, on Monday.

"Governor Corbett is recovering nicely," said Fye. "He presented to me approximately one month ago with typical spinal stenosis symptoms."

The first lady said the governor had back pain and pain when he walked during the campaign, but he thought it would come to an end when he took office.

"We thought at first, once he was off the campaign trail and with a few months of exercising, it would improve, but when it didn't, that's when we started investigating what it was," said Susan Corbett.

A local spine specialist, Dr. William Cano of Performance Spine and Sports Physicians in Pottstown, Montgomery County, explained what the doctors in Pittsburgh did to the governor to release the pressure on his nerves in his spine.

"Removes the lamina on both sides, usually, and the spinal process, which is this spine bone which we all feel the ridges of the back," said Cano, pointing to a spine model. "It's a relatively easy procedure and it has very good results because people experience improvement in their leg pain fairly soon after surgery, perhaps with a little bit of rehabilitation afterwards."

"He's alert, joking with the nurses," said Susan Corbett at a news conference in Pittsburgh. "As soon as he became governor he had a big smile on his face and asked for coffee. And we told him, he was governor everywhere but the recovery room because he can't have any of that."

"I expect a full recovery and I think he'll most likely get out of bed this evening," said Fye.

Doctors said the governor will be in the hospital at least 24 hours. He'll then spend several days recovering at his home in suburban Pittsburgh.

Lt. Gov. James Cawley of Bucks County served as acting governor while Corbett was under general anesthesia.