Concussion in high school sports are rising at a 15% annual rate, a new study finds. Football tops the list of sports with the highest rates, with girls soccer a distant second among the 12 sports studied.
Studying concussion data for 6 boys' sports (football, lacrosse, wrestling, soccer, basketball and baseball) and 6 girls' sports (field hockey, lacrosse, soccer, basketball, cheerleading, and softball) gathered at 25 public high schools in Fairfax County, Virginia over an 11-year period (1997-2008), researchers from Maryland and Virginia found a 4.2-fold increase over the study period, with concussion rates increasing acr;ss all 12 sports studied, from an average annual increase of 8% for football to 27% for wrestling,The study is reported in the American Journal of Sports Medicine.
- The overall (12-sport) concussion rate increased from 0.12 per 1000 AEs (Athletic exposure = one athlete's participation in a practice or competition) in 1998 to 0.49 per 1000 AEs in 2008;
- Girls had a higher rate of concussion that that of boys in those sports (soccer, basketball, baseball/softball) where the boys' and girls' games are essentially the same. While the reasons for the increased rate remain unclear, a possible bias towards increased reporting of concussion in females continues a likely factor;
- While the concussion rate in cheerleading was relatively low (0.06), the low rate was heavily influenced by the large number of athletic exposures (games and practices) and the fact that participation spans both multiple sports seasons during an academic year. The sport had the second highest absolute number of concussions among girls over the study period behind girls soccer, making the implementation of prevention strategies critical;
- While rates for all 6 boys' sports, whether helmeted or not, increased over time, rates for helmeted sports (football, boys lacrosse, baseball) were nearly twice those of non-helmeted sports. Such findings were, the researchers noted, consistent with previous studies reporting that use of protective equipment does not have a conclusive effect on concussion risk in high-impact helmeted sports and that protection from concussion requires a multifaceted approach to injury prevention.
- Repeat concussions represented 11% of all concussions. Among athletes with repeat concussions, the median interval between concussions was 316 days, but 19% occurred less than 1 month apart.
Concussion Rate (per 1000 Athletic Exposures)
|Annual Increase, %
Possible reasons for increased rates
Among the possible explanations for the year-to-year increases in concussion rates across all sports were the increased availability of ATCs, under-reporting in earlier years, increased intensity of play and greater concussion awareness as a result of extensive media coverage of concussion risk.
While the data revealed an overall increase of 16.5% in annual concussion rates over the past decade, a substantial increase in rates was seen beginning in 2005, when the high schools participating in the study increased athletic trainer coverage from 2 part-time positions to 1 full-time and 1 part-time positions.
Increased access to a trained professional "may have contributed to improved reporting of concussions among student-athletes," said Andrew E. Lincoln, ScD, MS, Director of the Sports Medicine Research Center, MedStar Health Research Institute at Union Memorial Hospital in Baltimore in an interview with MomsTeam. "Having access to an allied health provider, particularly an athletic trainer who often sees student-athletes on a daily basis, would likely facilitate increased reporting of concussions." He could not, however, rule out other possible reasons for the increase in concussion rates.
There is also a "strong possibility," said Dr. Lincoln, that one factor contributing to the increase seen in concussion rates was "under-report[ing] in previous years before the recognition of concussion signs and symptoms among medical professionals as well as players, coaches and parents reached the current level of understanding." He nevertheless cautioned that, "We still have a long way to go in terms of getting athletes and teammates to recognize and report their signs and symptoms rather than honor a duty to their team/coach/teammates to stay in the game following an injury," a phenomenon some dub the "code of silence."
While the study found it unlikely that the increased concussion rates seen since 2005 were due to the increased intensity of play widely observed in high school sports (because, said the study authors, it would not have led to large increases occurring consistently across all sports at one point in time), "There may be some truth that today's more aggressive nature of play and improved athletic capabilities (i.e. bigger, faster, stronger athletes) that result in greater kinetic energy transfer may also contribute to the increased rates that we observed," said Dr. Lincoln.
The researchers suggested that the increased concussion rate observed over the study period in each sport might also be reflection of the extensive media coverage of concussion risk in recent years in professional and amateur sports" and new state laws and rule changes and treatment recommendations by the NCAA, NATA, NFHS, CDC, and sports-governing bodies which have contributed to greater concussion awareness of concussion among players, coaches, parents, and clinicians.
For an article comparing concussion rates reported in studies from 2004, 2007 and 2011, click here.
For the most comprehensive, up-to-date concussion information on the Internet, click here.
Source: Lincoln A, Caswell S, Almquist J, Dunn R, Norris J, Hinton R. "Trends in Concussion Incidence in High School Sports: A Prospective 11-Year Study" Am. J. Sports Med. 30(10) (2011), accessed January 31, 2011 @ http://ajs.sagepub.com/content/early/2011/01/29/0363546510392326.full.pdf+html
Published March 14, 2011; revised August 22, 2011