Engineers seek to reduce ATV injuries

Every year at OSF Saint Francis Medical Center in Peoria, doctors treat between 40 and 50 children who are injured while riding all-terrain vehicles that are designed for adults.

Nationally, more than 115,000 ATV riders ages 16 and younger are hurt on adult ATVs every year, according to Those are numbers that Dr. John Hafner, an emergency room physician at St. Francis, set out to reduce.

“We saw children getting hurt on adult-sized ATVs, but there hadn’t been a lot of work on the physics of why that happens,” Dr. Hafner says. “I thought this would be a valuable project for Bradley engineering students — to give biomedical answers to our anecdotal observations.”

The resulting study, “Definition and Measurement of Rider-intrinsic Physical Attributes Influencing All-terrain Vehicle Safety,” published in the Journal of Neurosurgery, was a collaboration among Bradley, St. Francis, the University of Illinois College of Medicine in Peoria and the Department of Neurosurgery at the Illinois Neurological Institute.

Three Bradley mechanical engineering students, under the guidance of professors Dr. Martin Morris ’77 MSME ’79 and Dr. Julie Reyer, developed an apparatus to measure the forces that undersized ATV riders experience on full-sized ATVs. Those vehicles can weigh more than 600 pounds and can reach speeds of 60 mph.

The researchers recruited a small adult to carry out controlled experiments on a closed course.

What they found was that lightweight riders with small arm spans — primarily children — are under considerable risk of injury when operating an ATV due to lateral, longitudinal and vertical operational instability.

“The implication for the average population is that full-sized ATVs are designed for adults,” Dr. Morris says. “Children don’t have the weight, height or range of motion required to control a large vehicle. They lose control, and that leads to collisions and injuries.”

Dr. Hafner adds, “Most vehicles are passive, but ATVs require drivers to be actively involved in steering and shifting weight. Generally, the smaller the child and the larger the ATV, the more serious injuries we see.”

As ATVs can cost several thousand dollars depending on the model, parents are reluctant to spend large sums on vehicles their children quickly will outgrow, Dr. Hafner says. But the researchers want parents and others to realize that appropriately sized ATVs come with increased rider safety and peace of mind.

“This study is important for consumers, doctors and engineers,” Dr. Hafner says. “It shows how collaborating with other disciplines can answer real-world problems.”