But doctors say there are steps parents can take to keep their children injury-free, and many involve common sense.
Keane says children should get in a minimum of one hour of activity to stay healthy, and spring's warmer weather helps make that possible. But parents need to chose ideal playgrounds for such activity, she says.
The primary concern about playground equipment, Keane says, is the surface. She says that it should be soft, so that it gives when children fall or land, and free of glass or other sharp objects.
"The biggest thing you need is to have supervision," Keane adds. "Children don't always know how to behave, and adults don't always know how to behave around children. You want your kids to have fun on the playground, but make sure to keep an eye on him or her."
Erin Spotte of Baltimore and Katie Burton of Perry Hall, Maryland, were following that advice recently while their young children played at Meadowood Park in Brooklandville.
They're part of a group of parents who meet each Friday at the playground, in part because its wood-chip and sand surface cushions falls. They also prefer areas that are fenced to prevent their children from wandering.
And while the group allows their children to frolic freely, Burton says, "At least one parent always has an eye on the other's child."
Her 2-year-old son, Andrew, enjoyed the monkey bars along with Spotte's 2-year-old son, Oscar. "We just keep our fingers crossed," Spotte says, "and hope no one falls."
Some parents take it upon themselves to ensure their children's safety on such equipment by using it with them. But that's not always a good idea.
Orthopedists at the Cleveland Clinic, for example, say they have seen an increase in tibia fractures in children who are going down playground slides with parents and grandparents.
Dr. Tracy Ballock, director of the Center for Pediatric Orthopaedic Surgery at the Cleveland Clinic, said children sliding with adults can catch their feet on the way down the slide and break a bone. "We recommend that children not go down the slide until they can climb the ladder on their own," Ballock says.
Parents can allay fears about playground injuries by ensuring that playground equipment is built to proper safety standards, said Dr. Keshia Pollack, assistant professor with the Johns Hopkins Center for Injury Research and Policy.
She pointed to 2009 U.S. Consumer Product Safety Commission data that showed there were 2,691 incidents associated with playground equipment from 2001 to 2008. The data showed that 67 percent of those incidents involved falls or equipment failure.
While the majority of the injuries the commission reported did not require hospitalization, there were 40 fatalities associated with playground equipment — including 27 that were the result of hangings and other asphyxiations, and seven that involved head and neck injuries.
The commission says that playground equipment should be age-appropriate. Children under age 2, for example, should use climbing equipment lower than 32 inches. Children ages 4 to 5 should use horizontal ladders 60 inches tall or lower. Spiral slides with a 360-degree turn are appropriate for children ages 5-12.
The CPSC says that if bare or painted metal surfaces are used on platforms, they should be oriented so that the surface is not exposed to direct sun year-round. All fasteners, connectors and covering devices should not be loose or be removable without the use of tools.
And all hooks, such as S-hooks and C-hooks, should be closed so that there is no gap greater than .04 inch (or about the thickness of a dime).