NEW YORK (CBSNewYork) – A new study found the number of playground injuries has decreased, because of both positive and negative factors.

Hunter College and Yale University researchers examined the number of visits to emergency rooms nationwide due to playground accidents between 2006 and 2014.

They attribute the decline in part to parental supervision and better construction.

“We know for sure that investing in the proper playground equipment and the infrastructure and in maintaining that equipment does pay off,” Hunter College researcher Peter Tuckel told WCBS 880’s Marla Diamond.

However, part of the reason for the drop could be that fewer children are physically active, Tukel says.

“That’s a little disconcerting,” he added.

There are more than 1,000 visits a year to emergency rooms across the country due to playground accidents. Most are from falling off monkey bars.