Well: At Playground, Child Plus Lap Can Equal Danger Last spring, Katie Dickman of Dunkirk, Md., was at the playground with her 18-month-old toddler, Hannah, when the little girl asked to ride down a twisting slide. Ms. Dickman accompanied her daughter, carefully keeping the child on her lap as they coasted to the bottom. But without warning, Hannah's sneaker caught on the side of the slide. Although Ms. Dickman grabbed the leg and unstuck her daughter's foot, by the time they reached the ground, the girl was whimpering and could not walk. A doctor's visit later revealed a fractured tibia. "My wife was just trying to keep Hannah extra safe and make sure she didn't fall," said Hannah's father, Jed Dickman. She felt very guilty about it. As the Dickmans soon learned, such injuries are surprisingly common. Although nobody keeps national statistics, orthopedic specialists say they treat a number of toddlers and young children each year with broken legs as a result of riding down the slide on a parent's lap. A study at Winthrop University Hospital in Mineola, N.Y., found that nearly 14 percent of pediatric leg fractures over an 11-month period involved toddlers riding down the slide with a parent. Dr. Edward Holt, the orthopedic surgeon at Anne Arundel Medical Center in Annapolis who treated Hannah's injury last April, said that just two weeks ago he treated a 4-year-old boy who had been injured going down the slide with his father. "This fracture is entirely preventable," said Dr. Holt, who has created a warning poster for local pediatrician offices and a You Tube video alerting parents to the hazard. This may be one of those counterintuitive cases when a child is safer by himself. If a foot gets caught while the child is sliding alone, he can just stop moving or twist around until it comes free. But when a child is sitting in an adult lap, the force of the adult's weight behind him ends up breaking his leg. The injury is typically treated with a cast from the foot to above the knee; the good news is that no surgery or resetting is needed. The child wears the cast for four to six weeks and heals without any lasting complications. But the damage is not merely physical. "The parents are always crushed that they broke their kid's leg and are baffled as to why nobody ever told them this could happen," Dr. Holt said. Sometimes one parent is angry at the other parent because that parent caused the child's fracture. It has some real consequences to families, and I hate to see it happen. The Mineola study was done by Dr. John Gaffney, a pediatric orthopedic specialist at Winthrop, after he had treated a rash of playground slide fractures. The hospital's data indicated that every sliding fracture involved a child younger than 3 riding in an adult's lap. The fracture might not be immediately obvious, but typically the child appeared to be in pain and could not put weight on the leg. Dr. Gaffney said he has treated three playground fractures in the last month for children sliding with a grandparent, a parent and a baby sitter. "As soon as the weather gets warm, this starts to happen," he said. "It's so common, but parents say: "How did I not know about this? I thought it was doing something good for my child by having them sit on my lap." " Andy Dworkin, a former journalist and who is now a medical student in Portland, Ore., said his son Felix, then 18 months, was playing with a toddler friend at an elementary school where they were drawn to a blue slide. Felix rode down first, on the lap of his mother, but his rubber-soled shoe caught on the slide and he started to scream when he got off the slide. Another mother, at the top of the slide with her own 17-month-old, quickly slid down with her son to try to help. But soon that little boy was crying as well. At the emergency room, both boys were found to have fractures, and they were fitted with orange and blue casts. "I was surprised at how easy it was for a young child to break their leg on a playground," said Mr. Dworkin, who wrote about the experience for his hometown paper, The Oregonian. I was even more surprised how nonchalant the hospital staff was about what was happening. They said they see this all the time. Both boys had full recoveries. Felix, now 3 ½, doesn't remember the accident, but will now go down small slides only and remains cautious around large twisting slides, said Mr. Dworkin. Dr. Holt said he did not want to discourage parents from taking their children to the playground or even playing on slides, but did want to spread the word about the risks of sliding with a child on your lap. To prevent the injury, the best solution is to allow a child to slide by himself, with supervision and instructions on how to play safely. Young children can be placed on the slide at the halfway point with a parent standing next to the slide. At the very least, parents should remove a child's shoes before riding down the slide with the child on their laps, and make sure the child's legs don't touch the sides or sliding surface. "I'm not saying we need to make the entire world out of rubber and insulate kids," he said. But this is something that is so totally predictable and preventable. That's why I want to get the word out this one could go away.