The Fall GuyPosted on October 22nd, 2012 No comments
Research by pediatric surgeon Peter F. Ehrlich may help make playground equipment safer and prevent thousands of injuries from falls each year
Hovering parents get a bad rep, but it’s a dangerous world out there. Falls account for about a third of unintentional injuries to children. They’re the number one reason for kids’ emergency room visits. And while infants often tumble from furniture, many older youngsters fall while climbing playground equipment — leading to roughly 15 deaths each year and 200,000 trips to the ED for broken bones, head injuries and open wounds.
Peter F. Ehrlich, M.D., associate professor of surgery at the University of Michigan Medical School and director of pediatric trauma at C.S. Mott Children’s Hospital, aims to cut those statistics dramatically. Ongoing research by Ehrlich and a team of colleagues centers on preventing injuries through a deep understanding of the biomechanics of falls. They believe their findings could aid the design of safer playground equipment and the crafting of smarter national safety standards.
“What we’ve found is that we can use much more sophisticated data to build safer playgrounds without taking away any of the fun,” he says. “We’re not saying that everybody needs to wear a helmet, knee pads or be in a plastic bubble when they go out to play — but, just like with the car industry, a state-of-the-art approach to safety can prevent a lot of trauma and a lot of pain.”
A review of data from Mott hospital found 1,015 children were hospitalized for falls between 2004 and 2007. Nearly 25 percent had a traumatic brain injury and 67 percent sustained fractures. Half of the cases were the result of falls from playground equipment.
The U-M researchers’ primary focus has been on children’s ability to hang onto the rungs and bars of jungle gyms and other climbing structures. Current handhold design recommendations are based on grip strength, which is generally measured using an adult-sized dynamometer — a device that’s held like a suitcase handle and squeezed like a nutcracker. But findings suggest that the measurement isn’t a reliable predictor of children’s ability to hang on.
“It doesn’t give complete information and it overestimates a child’s grip capacity, which varies by age, gender and hand,” says Ehrlich. “The numbers correlate, but they don’t provide the sophistication that needs to be there.” He compares the idea to declaring that all cars should have tires, but not looking closer at which tires would be most appropriate for each model.
With grant funding from the U-M Bone and Joint Injury Prevention and Rehabilitation Center, the research team — which includes faculty from the U-M College of Engineering with expertise in ergonomics and handgrip assessment — built a device to test children’s one-handed breakaway strength. To use it, a child hangs on to an instrumented rung, which is slowly raised until she can no longer support her weight and lets go. Breakaway force and torque data from the rung are recorded and a video camera captures changes in hand posture throughout the trial. Their findings are forthcoming in Human Factors: The Journal of Human Factors and Ergonomics Society.
The study showed that children’s capacity to hang onto bars with smaller diameters greatly exceeded their capacity to hang onto larger bars. “If you put a smaller kid on equipment with a larger handhold, they’re many, many times more likely to fall off,” says Ehrlich. “And that’s not including other factors, such as whether the rung is wet, whether it’s vertical or horizontal, whether it’s mobile or fixed, and so on.”
Ehrlich and his colleagues believe that that data from their research can inform a systematic approach to setting national standards for playground design, with age-appropriate recommendations for the size of rails and rungs, sliding poles, monkey bars and merry-go-rounds. A color-coded approach could help parents (and children) figure out whether a particular piece of playground equipment should be used; one color would indicate it was the right size for smaller children, while another might warn that it was made for larger hands.
“Injury is the number one cause of pediatric morbidity and mortality worldwide. In a certain sense, it may not be as splashy as cancer research — but the number of kids who get cancer is relatively small, thank goodness, compared to the dramatically larger number that get seriously injured in a variety of ways,” says Ehrlich, who also studies Wilms’ tumor and other childhood cancers. “That’s why injury prevention research is so critical.”