Age-based guidelines for all-terrain vehicles don't ensure the safety of young riders, according to preliminary results from an ongoing study at the University of Kentucky.
Current national guidelines establish appropriate engine size based on age, but they don't address the range of sizes and shapes that kids come in. And that can spell trouble for young drivers, researchers said.
If arms are too short, drivers can't steer well, said David Pienkowski, a professor of biomedical engineering at UK. If their hands are too small, they can't brake well. If their torso is too short, they can't see very far ahead.
"And remember, you're moving at 30 miles per an hour," Pienkowski said.
Although preliminary, the results show a need for caution, said Dr. Andrew Bernard, a UK trauma surgeon and one of the project's lead researchers.
"We've learned enough to know that great caution should be exercised when making a decision to buy an ATV for your child," Bernard said.
Between 2003 and 2006, 142 Kentuckians died in ATV accidents. Only West Virginia and Florida had more fatal ATV accidents, according to the most recent data available from the Consumer Product Safety Commission, which tracks ATV deaths. Nationally, there were 2,600 deaths reported. (The Consumer Product Safety Commission estimates there were almost 500 unreported deaths for a total of 3,100.)
In Kentucky, there are a growing number of ATV deaths each year, said Scott Wolfson, a spokesman for the commission.
For the UK study, researchers put children on an adult-sized ATV and a child-sized ATV to measure their positions at various degrees of incline. The experiments involved 11 children ages 12 to 15 and eight children ages 6 to 11.
Researchers measured the kids' ability to lift up, or post, when they go over a bump. If their legs are too short and they can't post, the ATV could send them into air when they go over a bump, Pienkowski said.
A large teenager on a small ATV also causes problems, the study found.
The study did not establish what would be a good fit, Pienkowski said. Instead, it looked for obvious misfits.
The data from the experiments will be used to design a larger study that could show what a good fit would be, Bernard said.
Part of the difficulty for the research team is the lack of information about what causes ATV accidents and how people are injured.
"We know so much about crash mechanics for automobiles," said Bernard. "We know very little about crash mechanics for ATVs."
The UK group is not the only group concerned about ATV size and kids.
The Consumer Product Safety Commission is working on new rules for ATVs. One of their proposals would expand the number of youth models from two to three and set speed limitations on the smaller models, Wolfson said. The group also is considering rules to make ATVs for children ages 12 to 15 wider and taller.
Because these kids are too big for youth models, they tend to ride ATVs designed for adults, Wolfson said.
"They are jumping on their parents' or their older siblings' ATVs and they are dying," he said.
The Specialty Vehicle Institute of America, an ATV industry group, said in a statement it has been working with the Consumer Product Safety Commission to develop new size guidelines to address size issues, especially for teens.
The guidelines, as outlined by the institute, focus on maximum speed limits and not frame sizes, which the UK study addresses.