Catastrophic brain injuries among high school football players appear to be increasing, according to data collected by the National Center for Catastrophic Sports Injury Research at the University of North Carolina.

Despite a widespread educational effort and rule changes designed to make the game safer, 13 high school football players suffered catastrophic brain injuries nationally in 2011, the most since the center began tracking them them in 1984.

The three highest yearly totals for football-related catastrophic brain injuries have come in the last four years.

“I think a part of it is that we are educating people better and injuries that might not have been reported in the past are being reported now,” said Bob Colgate of the National Federation of State High School Associations. “But we also have a responsibility to keep emphasizing that the head has to be taken out of tackling and blocking.”

From 1984 until 2007, the number of catastrophic brain injuries was nine or less each year. The total rose to 10 brain injuries in 2008 and 10 again in 2009.

The 10-year average for brain injury was 5.0 in 1992 through 2001 but has risen to 8.2 for 2002 through 2011.

“This is a major problem,” said Dr. Fred Mueller, the report’s lead author, director of the center and professor emeritus of exercise and sports science in the College of Arts and Sciences.

Mueller said that the head cannot be used as the initial point of contact during blocking and tackling. A 1976 rule change made it illegal to lead with the head in blocking and tackling, but Mueller believes the rule must be enforced more vigorously by officials and that coaches must teach the proper fundamentals.

Improper tackling and blocking techniques also were a factor in six high school players having cervical cord injuries with incomplete recovery.

Mark Dreibelbis, the N.C. High School Athletic Association supervisor of officials, said officials are trained to look for players leading with their heads while tackling and blocking.

“This is something that we work at all of the time. We discuss the rule, and we watch clips,” he said.

Concussions and brain injury are a national topic for football at all levels.

North Carolina passed a law in 2011 that requires middle school and high school players who are suspected of having a brain injury to leave a game and not return to play or practice until after being cleared by a medical professional.

Dreibelbis said football game officials have been trained in recent years to look for players who seem to have received a head injury. If an official escorts a player to the sidelines because of a possible medical condition, the player cannot return to play until he has been cleared by medical personnel.

The National Federation of High School Associations and the NCAA adopted rules this year that send players whose helmets come off to the sidelines to have the helmets fitted better.

The NFL has changed its kickoff rules in an effort to reduce concussions, and New York Giants owner John Mara recently said that he could envision a day when kickoffs might be eliminated.

At least six of the players who had catastrophic brain injuries in 2011 had experienced a previous brain injury.

Defensive players are much more likely than offensive players to have a catastrophic injury. Tackling has been associated with 66.7 percent of catastrophic injuries since 1977.

The center has collected data and published annual reports on catastrophic football injuries, including fatalities, disabilities and serious injuries for 48 years and began collecting brain data in 1984. The report defines catastrophic injuries as those that result in brain or spinal cord injury or skull or spine fracture, which involve some disability at the time of the accident.

The report’s recommendations also include schools hiring coaches who teach proper fundamental skills, and schools retaining athletic trainers certified by the National Athletic Trainers’ Association.

Stevens: 919-829-8910