Adolescent gymnasts are developing arm, wrist and hand injuries rarely seen before, say two doctors who've studied the MRIs of young gymnasts complaining of hand or wrist pain.

"These young athletes are putting an enormous amount of stress on their joints and possibly ruining them for the future," said Dr. Jerry Dwek, lead author of a study of 125 patients, ages 12-16, who suffered chronic wrist or hand pain.

Earlier studies have reported injuries to the bones of adolescent gymnasts have been rising. But the paper presented by Dr. Dwek and his coauthor, Dr. Christine Chung, at the annual meeting of the Radiological Society of North America in Chicago Dec. 1 uncovered some injuries that have not previously been reported. Both Dr. Dwek and Dr. Chung are on the radiology faculty at the University of California, San Diego.

"We were surprised to be looking at injuries every step down the hand all the way from the radius to the small bones in the wrist and on to the ends of the finger bones at the knuckles," Dr. Dwek said. "These types of injuries are likely to develop into early osteoarthritis."

Gymnasts and the physicians who treat them have long been familiar with an ailment known as "gymnast's wrist," a shortening of the radius, the bone in the forearm that takes the most stress during gymnastics, said Dr. Victor Prisk, an orthopedic surgeon at UPMC who was an all-American gymnast at Michigan State University. Due to damage to the radial growth plates, the bone does not grow in proportion to the rest of the skeleton, in particular in relation to the ulna, a long bone in the forearm which runs parallel to the radius. Some former gymnasts have to have surgery later in life to shorten the ulna to regain the proper fit of the wrist bones into the forearm.

"This study seems to be showing there is a new problem, a flattening of the metacarpal heads from the constant pounding," Dr. Prisk said. "Having been a gymnast myself for 20 years, I understand the stress it puts on joints. There is probably no other sport that puts quite as much stress on the wrist and hand."

But Drs. Dwek and Chung were "making a leap" when they asserted the wrist injuries gymnasts suffer could cause arthritis in the future, said Dr. Prisk, who is a team physician for the Pitt gymnastics team.

"There are no studies which show this progresses to arthritis," Dr. Prisk said.

Drs. Dwek and Chung drew broad conclusions from a pretty small sample, said Dr. Mark Baratz, chief of the division of hand and upper extremity surgery at Allegheny General Hospital, and a medical consultant to the Pittsburgh Pirates.

"The study basically looked at the MRIs of 125 kids, of whom only a dozen were gymnasts," Dr. Baratz said. "They saw mostly things we expect to see in gymnasts. What they saw that was uncommon was a problem with the bone by the knuckle. In two kids, there was what was described as a vascular necrosis [early death] of the bones of the knuckles."

"When you think about all the kids who are involved in gymnastics, these problems are uncommon," Dr. Baratz said.

But the study indicates it's important for parents and coaches not to be dismissive when a young athlete complains about pain, he said.

"The right thing to do is to check things out," Dr. Baratz said. "MRIs can help us confirm suspicions or diagnose problems in these kids."

"It is possible that by changing the way that practice routines are performed, we might be able to limit the stress on the joints and on delicate growing bones," Dr. Dwek said.

Former Pitt gymnast Edward Swerdlow is co-owner of Gymkhana Gymnastics Schools, which offer both recreational and competitive gymnastics training for young people in the Pittsburgh area. Mr. Swerdlow said he wants to read the study, but expressed skepticism at its findings.

"Our injury rate has been pretty similar for the last 20 years," he said. "But then we've been doing things the same way for the last 20 years."

The most common injuries his students suffer are twisted ankles or shin splints, Mr. Swerdlow said. Wrist injuries typically occur when a student lands improperly and uses her hands to break her fall, he said.

The primary reason why there are more injuries to adolescent athletes today is because more adolescents -- especially adolescent girls -- are taking part in competitive athletics, Mr. Swerdlow speculated.

"It's like driving a car," he said. "The more often you do something, the more likely it is you'll get hurt doing it."