Deniz Ince loves playing football and baseball video games on his Wii video game console, and says he would swing, pitch and throw with the controller for up to two hours a day when he didn’t have school.

But he soon noticed an unwelcome side effect – wrist pain. And one day, the 11-year-old, who lives in St. Louis, Mo., noticed that his thumb was starting to hurt.

 He asked his father, who is a rheumatologist, if he was going to get arthritis or tendinitis from playing video games. His dad replied that he didn’t know.

Deniz decided he wanted to find out, so he teamed up with Yusuf Yazici, MD, a researcher at New York University School of Medicine, who is one of his father’s colleagues.

The two of them administered questionnaires to elementary school children to find possible associations between pain levels, type of game device, a gamer’s age and how long they played.

Of the 171 children who participated, more than half were girls. The average age of kids in the study was 9.3 years, and 80 percent of them reported playing with a console or handheld.

Almost half of participants reported using these games and devices for less than an hour each day. One-third reported one to two hours of game play daily. Seven percent reported two to three hours per day, and 6.4 percent reported more than three hours each day.

The findings of the study, which were presented this week at the 2009 annual meeting of the American College of Rheumatology in Philadelphia, determined that playing with a video game console, which is an interactive entertainment computer or electronic device, or a hand-held video game, is in fact associated with increased joint pain in young children.

In particular, 12 percent of children reported finger pain, and nearly 10 percent reported wrist pain that limited the amount of time they were able to play video games.

Researchers also discovered that the youngest participants, who were 7 years old, experienced the greatest pain.

Dr. Yazici says he isn’t sure why.

“It seems the younger a kid is when they play with game consoles and handhelds, the more pain they have, regardless of the time spent playing each day,” says Dr. Yazici, who is the director of the Seligman Center for Advanced Therapeutics at NYU. “It may be that they haven't developed their muscles and tendons enough or as much as an older kid to handle playing with gaming devices.”

And playing Wii video games exclusively resulted in more self-reported pain – regardless of age and hours of play.

“My original goal was to prove that the new game systems don’t cause any problem or pain because they are mostly tilt, not press,” Deniz says, “but my study showed otherwise. I hope my friends won’t be too mad at me.”

John Sperling MD, MBA, an orthopedic surgeon at the Mayo Clinic in Rochester, Minn., says the findings are interesting.

“I think the big difference between the video games and sports is that for most sports, people are involved in training and practice but with many games like Wii, there’s no specific training or any degree of fitness required to do them,” he says.

“The other issue is that when people participate in these activities and use the controller, they’re swinging their arm in space, and there’s no resistance, as there is when you swing a tennis racket and the resistance stops your arm from moving forward. So what we see is people with repetitive type injuries. Particularly I see it in the shoulder quite a bit,” he adds.

Barbara Adams, MD, the director of pediatric rheumatology at the University of Michigan in Ann Arbor, is hearing similar reports.

She says just a week ago she saw a 14-year old with severe right arm, shoulder and neck pain who mentioned that she got a Wii for her birthday.

“I began asking her what games she played with it. It was mostly tennis and bowling,” Dr. Adams says. “She told me her friends would come over and they would do this for several hours at a time. And sometimes, it would be five days a week if there was nothing else to do.”

Researchers note that these study findings might suggest there should be a minimum age for children to start using these games and devices, but Dr. Yazici says there is no data to say what the best age is for children to start playing video games. He does believe though that his findings indicate that 7 seems too soon.

“Our data suggest that amount of time spent playing did not make a difference on the pain felt in each group, when we controlled for time spent, younger age still had more pain than older age kids,” Dr. Yazici says.

Researchers are planning another study to look at the kinds of injuries that caused the pain in children’s wrists and fingers and to see if that pain is likely to resolve as they get older or get worse.

They don’t know if the injuries put children at increased risk for arthritis.

“I think these kinds of studies need to be done more frequently,” Dr. Yazici says. “We were lucky that Deniz was observant enough and clever enough to develop a hypothesis from what he observed in his everyday life and helped us test it.”