GREEN BAY, Wis. (AP) -- Changes to the NFL's kickoff rules appear to account for a slight decline in the number of concussions reported across the league last season.

That's according to a new study of injury data provided by the NFL Players Association.

Jesse David, senior vice president at Edgeworth Economics, tells The Associated Press that the number of concussions reported on kickoffs decreased by about 43 percent from 2010 to 2011. The resulting slight dropoff in the overall number of reported concussions reverses a trend toward more head injuries in recent years.

There were 266 overall concussions reported last season, a decrease from the 270 reported in 2010. The number of concussions that occurred on kickoffs dropped from 35 in 2010 to 20 in 2011.