Gov. Martin O'Malley says he learned a hard lesson last week: He's not 20 anymore.
Hoping to add spice to his workout routine, the 44-year-old politician abandoned the elliptical machine in favor of some "high-impact running" on the treadmill, only to develop sharp pain in both knees. The pain in the right one went away, he said, but the left just got worse.
A trip to the doctor Thursday confirmed that he had suffered a stress fracture in his left tibia and will be forced to use crutches for four to six weeks, he said.
"I had a pretty good routine down where I would run every four years," he said.
He said he tried to play through the pain for about a week, and was noticeably limping at some public events. The fracture was diagnosed by Dr. Andrew Cosgarea, director of the Division of Sports Medicine and Shoulder Surgery at Johns Hopkins Hospital.
"I tried to power through it," O'Malley said. "The doctor said, 'You can't power through it. It's a fractured bone.'"
O'Malley has been a gym rat since his days on the Baltimore City Council, and before being elected governor, he could frequently be found pumping iron at the Downtown Athletic Club. But it was sleeveless T-shirts he was famous for, not shorts, and he said his career as a runner lasted all of three days.
"That was a mistake, in retrospect," he said.
Experts say that tibial stress fractures are caused by the repetitive loading of weight on the lower leg. They're common among joggers, competitive athletes and military recruits who spend a lot of time marching or jogging.
"It's a microfracture through the bone, where strength of the bone just fails," said Dr. James C. Dreese, an orthopedic surgeon and sports medicine specialist at University of Maryland Medical Center and a team physician for the university's athletic program.
The tibia, also known as the shinbone, is one of two bones that connect the knee to the ankle. But unlike the other connecting bone, the fibula, the tibia bears all of the body's weight with each step, Dreese said.
O'Malley said his fracture runs in a horizontal line just below the joint between the tibia and the kneecap.
A jogger who suffers the injury while running will typically experience increasing discomfort. "It's typically a sharp, shooting pain whenever they put weight on it," Dreese said.
Healing a microfracture of the tibia by staying off the leg for six weeks is a "standard course of treatment," Dreese said.
"You want them not to put any weight on it so the bone can heal," he said.
The injury can happen at any age, although the most susceptible group is adolescent girls, he said. Runners who suffer one stress fracture are more likely to suffer one again.
An Israeli study in 2003 showed that treadmill runners are less likely to sustain tibial stress fractures than outdoor joggers. But Baltimore-area physicians say the injury can happen anywhere.
"Usually it doesn't make any difference where someone is running," said Dr. Les Matthews, chief of orthopedic surgery at Union Memorial Hospital.
While recuperating, people with tibial stress fractures can take up swimming or bicycling -- but they should continue to watch for warning signs, Matthews said.
"What we generally tell people is pain should be the guide. If you ride a bike and it hurts, don't do it. If swimming hurts, don't do it," Matthews said.
Josh Levinson, who owns the Charm City Run stores in Timonium and Bel Air, said it's a mistake for new runners to try to do too much too soon. Even if someone, like the governor, is in good shape, running uses different muscles and puts different stress on the body, and any new routine should start slowly, Levinson said.
And although treadmills might seem gentler than road running, they can still lead to injuries, he said.
"On a treadmill, if you go on a steep incline, you can really hurt yourself by putting stress on your calf and Achilles," Levinson said. "Although people recommend treadmills because they're such a soft surface, the repetition can really hurt. You never change your range of motion -- the undulation of hills here and turning and short strides and long strides -- those kinds of things are very good for the body, even though the surface is a lot harder. On the treadmill, you're just pounding the same joints every time."
O'Malley's wife, Baltimore District Judge Catherine Curran O'Malley is a longtime runner, but the governor said his brief stint on the treadmill will be his last: "I'll let Katie handle the distance running."