New Study: Football Players With Concussion Three Times More Likely To Suffer Another One

The study, published in the September-October issue of the American Journal of Sports Medicine, suggests that the brain is more susceptible to injury when it has not had enough time to recover from a first injury. Researchers say the finding is important because concussions can lead to permanent brain damage, vision impairment or even death if not managed properly.

"We believe recurrences are more likely because injured players are returning to practice and to games too quickly after blows to the head," said Dr. Kevin M. Guskiewicz, assistant professor of exercise and sport science at UNC-CH and study leader. "Many clinicians are not following the medical guidelines that players should be symptom-free for several days before returning."

Guskiewicz directs the Sports Medicine Research Laboratory and the Undergraduate Athletic Training Education Program, both at UNC-CH. Co-authors of the new paper are Nancy L. Weaver, research associate for the N.C. High School Injury Surveillance Program; Darin A. Padua, doctoral student in sports medicine at the University of Virginia; and Dr. William E. Garrett Jr., professor and chair of orthopaedics at the UNC-CH School of Medicine.

For three years, the researchers surveyed a random sample of 242 certified athletic trainers across the United States who worked with high school and college football teams. More than 17,500 football players were represented in the study, which covered 1995 to 1997. About 5 percent suffered concussions each year. Researchers also conducted telephone interviews with a smaller group.

"We wanted to learn more about concussions -- the incidence of injury, the mechanism of injury and whether players seemed to be injured more frequently on artificial turf than on grass," Guskiewicz said. "We found the incidence of injury to be highest at the high school and Division III level, while Division I and II college players suffered fewer concussive injuries."

Possible explanations include poorer quality and fit of protective equipment, he said. Another possibility is that college players are more skilled on average, and better players are known to be less susceptible to injury.

The UNC-CH professor and colleagues found that 31 percent of athletes with concussions began playing again the same day they were injured.

"This didn't surprise us, but it does worry us," Guskiewicz said. "Eighty-six percent of players reported having at least a headache after the incident, and you should never return to play with a headache. It was probably all right for the 14 percent of players with no symptoms to return."

Artificial turf didn't produce more head injuries than natural grass, the researchers found. Concussions on artificial turf, however, were more serious. Artificial athletic fields are sheets of synthetic grass over shock-absorbing pads stretched across concrete slabs.

Another key finding was that only one in 20 players suffered a concussion during the season rather than the one in five reported in 1983. Almost 15 percent of injured players suffered a second concussion in the same season, and it tended to be more serious than the first. The most common symptoms were headache, dizziness and confusion.

"That earlier 20 percent figure appears to have been a gross over-estimation," Guskiewicz said. "Still, the rules have changed to make the game safer and the equipment, especially helmets, are safer and have to be approved by the National Operating Committee on Standards in Athletic Equipment (NOCSAE). Also, many coaches are being smarter in limiting physical contact time in practices. They are stressing the importance of players keeping their heads up during blocking and tackling, not dropping their heads, which is against the newer rules and is much more dangerous."

Defensive backs, offensive linemen and linebackers were the most frequently concussed players, but special team players and wide receivers were more likely to suffer more serious concussions. During the 1999 season, all six U.S. high school players killed as a direct result of football accidents died from injuries to their brains, according to a different UNC-CH study released in August.