Brain injuries associated with full-contact football appear to be rising among high school students, a new report says.

2011 saw 13 injuries that resulted in permanent disability among high school students. The number, until recently, remained in single digit, according to the latest catastrophic football research annual report from UNC-based National Center for Catastrophic Sports Injury Research.

According to the researchers based at University of North Carolina at Chapel Hill, the increase is alarming and indicates that more coaches and athletic trainers should change how they teach the fundamental skill of the game.

“These 2011 numbers are the highest since we began collecting catastrophic brain injury data,” said Fred Mueller, the report’s lead author. ”This is a major problem.”

About 4.2 million football players compete nationwide, including 1.1 million high-school students.

The center has collected data and published annual reports for more than 48 years on catastrophic football injuries, including fatalities, disabilities and serious injuries.

Since 1977, about 67% of football-related catastrophic injuries have been suffered by players as they made tackles. Mueller said part of the problem is that despite being prohibited in 1976, head-to-head contact - such as butt-blocking, face tackling or spearing tackles - is still occurring. These strategies make the head the initial primary contact with an opposing player, and often lead to cervical spine fractures or permanent brain injuries.

Since 1984, there have been 488 cervical cord and cerebral injuries with incomplete recovery, including 164 brain injuries, of which 148 were among high school students.

2001 to 2010 saw a 25% jump in football-related disability brain injuries over the previous decade, increasing to 66 from 32 incidents among all types of players.

Mueller said reversing the trend required several changes. Coaches must be well versed in the signs and symptoms of concussions, such as headaches, dizziness, nausea and light sensitivity, and pull players from the game if they exhibit those indicators.

The report also recommends that schools should hire coaches who teach proper fundamental skills, and retain athletic trainers certified by National Athletic Trainers’ Association. Referees must be vigilant about throwing flags when they see illegal tackles and parents also must be involved in meetings and discussions about concussions.

“All these measures are important if we want to continue to make a positive impact on the game,” he said.” We have to continue research in this area. Accurate data not only indicate problem spots, but they also help us offer appropriate precautions and reveal the adequacy of our preventive measures.”

In a separate report, Centers of Disease Control and Prevention had said that high school athletes account for an estimated 2 million injuries, 500,000 doctor visits and 30,000 hospitalizations annually.