Scan Is Set for Bush’s Aching Knees

President Bush is scheduled to undergo a magnetic resonance imaging scan today so doctors can pinpoint the reason for his aching knees, which have sidelined him from running, his favorite form of exercise, the White House said Wednesday.

The procedure is to be performed at Washington’s Walter Reed Army Medical Center.

Bush, 57, is a serious exercise buff, but he has been slowed since early this year by his knees and by a torn muscle in his right calf. That was caused by insufficient warmups before running, the president has said. After the tear, Bush continued running hard and aggravated the injury.

Later, he used an elliptical trainer, swam and “water-jogged” in the White House swimming pool. He also continued lifting weights.

“He’s still working out regularly, but he does enjoy running,” White House Press Secretary Scott McClellan told reporters aboard Air Force One Wednesday morning en route to Kill Devil Hills, N.C., where the president spoke at the 100th anniversary celebration of the first flight by Orville and Wilbur Wright.

Despite on-and-off rain, thousands of history and aviation buffs turned out to hear the president and partake in the festivities.

Speaking from a pavilion that afforded only partial shelter from the rain, a bare-headed Bush kept his remarks brief -- just 23 minutes -- and then left immediately for Washington.

He praised the Wright brothers’ perseverance in the face of widespread doubts about manned aviation.

“There is something in the American character that always looks for a better way, and is unimpressed when others say it cannot be done,” he said. “The Wright brothers’ invention belongs to the world, but the Wright brothers belong to America.”

The president already was scheduled to visit Walter Reed today to spend time with U.S. soldiers wounded in Iraq and Afghanistan, McClellan said.

MRIs produce high-resolution images that help doctors see small structures, allowing for more accurate diagnoses. After the exam, Bush will consult with his personal physician, Dr. Richard Tubb, and an orthopedic surgeon about any other procedures that might be called for, McClellan said.

The president’s condition does not sound uncommon for aging athletes, said Dr. James Garrick, an orthopedic surgeon and head of the Center for Sports Medicine at St. Francis Hospital in San Francisco.

A calf injury like the one the president suffered this year often can lead to a knee problem on the same side, especially when the athlete resumes running before the calf muscle’s strength and flexibility are fully restored, Garrick said. That causes the athlete to unconsciously favor that leg, leading to the knee pain, he added.

He said Bush’s MRI was likely to turn up a tear in the meniscus, or knee cartilage, if for no reason other than his age. “An MRI on a 57-year-old person who’s been active is undoubtedly going to show some abnormality,” Garrick said in a phone interview from San Francisco. But a simple tear in the meniscus would not necessarily require any medical treatment, he said, adding that a full recovery would come with time -- and specific exercises designed to regain the calf muscle’s strength and flexibility.