WASHINGTON -- Exercise by young athletes -- especially by those who train in one sport -- can cause stress fractures of the back, doctors say.
Spondylolysis, often-painful tiny cracks in spinal bones, may account for almost half of low back pain cases among active teen-agers who seek medical attention for their pain, according to a report in the January issue of the medical journal The Physician and Sports Medicine.
And spondylolysis is more common than doctors visits indicate, the article said. Teens "often cope with the condition by hoping it will just go away," the journal reported.
In many cases, it does go away, or teens play despite the pain. But treatment can reduce the pain and possibly head off a recurrence.
Those who specialize early
Spondylolysis typically happens to young athletes who specialize early in a sport such as gymnastics which can require the athletes to bend repeatedly far backward, putting pressure on bones in the lower spine, said Dr. James L. Moeller. Chairman of sports medicine at William Beaumont Hospital in Troy, Mich., Moeller was co-author of the journal article.
Risk of injury rises with the level of competition and time spent in a sport, Moeller said. The risk is greater in college or pro activity than in middle or high schools, he said, but young athletes who specialize early in one sport face similar dangers.
It would be better if kids varied their sports while they were young, and didn't decide on a favorite until they were in their early teens, Moeller said. This would reduce the risk of overuse injury, he said.
Young athletes also can reduce their risk by strengthening muscles in the abdomen, as well as hip flexors and other muscles that support the back, Moeller said. Typically, however, coaches prefer to focus their limited training time on muscles needed for the sport instead of on prevention of injury, he said.
"I think if they work on this prior to any problems, they might be able to avoid the problems altogether," Moeller said.
Pain in backbend a sign
Doctors look for the condition by having the patient bend backward. If it hurts, that's a sign of spondylolysis. The tiny cracks also can show up on X-rays, but more sophisticated imaging may be needed to make a diagnosis, the journal article said.
The cracks can heal in two ways -- the bone fuses back together, or a softer material called collagen fills in the crack. Collagen self-repair is less stable, however, and increases the possibility of a recurrence of spondylolysis, said Dr. John Sarwark, a professor of orthopedic surgery at Children's Memorial Hospital in Chicago.
Doctors treat the condition with painkillers, a back brace to stabilize the area of the spine affected and time away from physical activity.
"If we got the kids early and brace right away, most go back to all activity in two months," Sarwark said. Kids we got later -- after six months or more of symptoms -- took longer."
Some of the later cases had to wait up to year to play without pain, said Sarwark, who reported on injuries in 2000 in the Journal of Pediatric Orthopaedics.
Doctors differ in their opinions on when young athletes are fit to play. Sarwark allows children to play while wearing the brace, as long as the pain is manageable. Moeller prohibits play until the brace is removed.
However, the doctors agree that spondylolysis is highly treatable and that few cases go on to require surgery.