Girls who play high school sports have a higher rate of concussions, and concussions account for more of their injuries than found in boys, according to a study in the December issue of the Journal of Athletic Training (42(4):495–503).
Among findings, girls who played high school soccer sustained concussions 68 percent more often than boys (p=.03), and concussions made up 15.1 percent of their total injuries, compared to 9.4 percent for boys playing the same sport (p=0.01).
The disparity was also seen for basketball. Girls who play high school basketball had almost three times more concussions than boys (p<.01), and concussions accounted for 11.7 percent of the girls' injuries as compared to 3.8 percent for boys (p<0.01).
Study co-author Christy L. Collins said the differences in concussion rates between boys and girls may be explained by biomechanical and sociological factors, as well as by differences in playing styles.
“As we learn more about concussion rates, patterns, and risk factors, we can start putting into place interventions,” she said. Programs aimed at teaching parents and coaches about concussions, as well as better equipment, and stricter enforcement of safety rules may lower concussion rates, she said.
Researchers at Ohio State University and Nationwide Children's Hospital (both in Columbus, OH) analyzed data from 100 U.S. high schools and 180 U.S. colleges from 2005 through 2006. In all, college sports players had higher rates of concussions than high school athletes (0.43 concussions per 1,000 college games or practices versus 0.23 concussions per 1,000 high school games or practices). However, concussions represented a greater proportion of injuries among high school athletes (8.9 percent versus 5.8 percent).
High school football had the highest rate of concussions: 40.5 percent. This was followed by girls' soccer (21.5 percent), boys' soccer (15.4 percent), and girls' basketball (9.6 percent).
REASONS FOR DIFFERENCES
Collins said that girls have smaller ball-to-head ratios and weaker necks, which may partially explain why they are more susceptible than boys to concussion.
In fact, an August article in the British Journal of Sports Medicine, which summarized previous studies of concussions amongst female soccer players, reported that differences in women's neck strength and girth, as well as head mass — compared to men's — may make them more vulnerable to concussions (41 Suppl 1:44–46).
Christopher Giza, MD, a pediatric neurologist and neuroscientist studying developmental brain injury at the University of California-Los Angeles, said these biological findings contradict previous studies that suggested that the female hormones estrogen and progesterone may be neuroprotective in brain injury. But Dr. Giza, who was not involved in the Journal of Athletic Training study, added that most of these studies have been done in animal models of severe traumatic brain injury and therefore, “it is inconclusive as to whether the lab results directly translate to the human condition.” Since concussions are considered mild injuries with little, if any cell death, he said, “that naturally leads to the authors' conclusions that factors other than hormonal contributed to the gender difference in post-concussion syndrome.”
The study authors also suggested that cultural tendencies encourage girls to report injuries while boys are expected to “tough it out,” a difference that could explain the different concussion rates. Coaches, athletic trainers, and parents may treat head injuries in girls more seriously or delay return to play, researchers stated.
But Collins told Neurology Today that as girls' sports become more competitive, it is possible that “girls are under more pressure to increase toughness and level of play.”
She also said that differences in playing styles may explain why girls report more concussions. For example, she and colleagues found that in high school soccer, boys sustain more concussions while goaltending and girls sustain most of their concussions while defending.
Concussions can lead to long-term behavioral and cognitive problems, said Michael V. Johnston, MD, chief medical officer and senior vice president of the Kennedy Krieger Institute, and professor of neurology, pediatrics, and physical medicine and rehabilitation at Johns Hopkins University School of Medicine. Cognitive problems include difficulty in decision-making and executive functioning, such as being able to write at the same level as before the injury. Trouble maintaining self control or overcoming apathy are common behavioral issues, he said.
Follow-up studies should research the degree of injury in boys and girls who sustain concussions, Dr. Johnston said. “They should try to figure out, given the same kind of injury or force supplied, whether boys or girls have different levels of impairment,” he said.
Collins said she and colleagues chose to study concussion rates in high school and college athletes because concussions aren't only a concern for high school football players. Concussions are a serious injury that can happen to athletes playing all types of sports at all levels of play, she said, pointing out that recent studies have suggested that players who sustain multiple concussions are at greater risk for neurocognitive deficits.
“We want to get the message across that concussions aren't unavoidable sports-related injuries,” she said. “They can be prevented and the concussion rates can be reduced through targeted, evidence-based interventions.” She said the Centers for Disease Control's “Heads Up: Concussion in High School Sports” tool kit is a good resource for parents, coaches, and athletes to learn about concussion symptoms and management.
“This study suggests that the rate of injuries and the way in which injuries occur actually differs significantly based on gender and on the level of play,” Dr. Giza said. Physicians shouldn't think of current guidelines on concussion prevention and management as one size fits all: they need to be tailored according to age, gender, and type of sport, he said.
Collins said she and colleagues will use their concussion surveillance system to monitor how concussion rates change as new policies are implemented.
“It's not that we don't want kids to play sports, we just want them to be as safe as possible while doing so,” she said.