Our evolutionary history puts women at 50% more risk doing the same tasks as men. Men's upper bodies are better built to withstand sports.


When concussions make the news, it’s usually about football. But head injuries happen in other sports too, and not just to men. During a congressional hearing on concussions in youth sports on Friday, Dawn Comstock, an epidemiologist who studies sports injuries, told a House Energy and Commerce subcommittee that in sports like soccer and basketball in which girls and boys play by the same rules, with the same equipment and the same facilities, “girls have higher concussion rates than boys.” Comstock, a researcher at the Colorado School of Public Health, is the first author of a 2015 study published in JAMA Pediatrics that quantified concussions in high school soccer and found that they were about one and a half times more common in girls than in boys.

When U.S. Rep. Diana DeGette, D-Colo., asked whether more data was needed to show that girls have higher concussion rates, Comstock replied, “We already have the data that’s consistently shown this gender difference.” What we don’t have, she said, is a proven explanation for the discrepancy.

Some researchers have wondered whether women and girls are simply more likely to report their symptoms than men and boys are. “It’s a sexist way to say that they’re not as tough,” said Katherine Price Snedaker, executive director of Pink Concussions, an organization that is seeking answers to how concussions affect women and girls.

The group recently held a summit on female concussion and traumatic brain injuries at Georgetown University, and one of the speakers was Shannon Bauman, a sports physician who presented data from 207 athletes — both male and female — who’d been evaluated at her specialty concussion clinic in Barrie, Ontario, between September 2014 and January 2016. Bauman said concussions were often more severe in girls and women — she found differences not only in subjective reported symptoms but also in objective cognitive and visual symptoms that doctors noted during physical exams. Bauman counted objective physical signs of concussions such as trouble maintaining one’s balance and vision problems, and female patients had an average of 4.5 of them, compared with 3.6 for males. “Females are reporting more symptoms, but they’re also objectively having more physiological signs of concussion,” Bauman said.

The differences don’t stop there. Bauman’s data also showed that females take longer to heal. Thirty-four percent of men and boys who came to the clinic finished treatment within two months, yet only 12 percent of concussions in women and girls improved this fast. About 35 percent of females were still experiencing concussions six months or more after their injury.

Researchers are just starting to look for explanations for these differences, but hormones probably play some role, Snedaker said, because gender differences in concussions seem to emerge around puberty, when hormone levels change. Researchers at the University of Rochester School of Medicine and Dentistry have found that mild traumatic brain injuries heal less quickly when sustained during certain phases of the menstrual cycle, and they’ve proposed that the difference may come down to progesterone levels. Another proposed explanation, Bauman said, is that because women tend to have less neck strength than males, their necks aren’t as able to stabilize the head after they’ve been hit, resulting in more “sloshing” as the brain shifts in the skull.

The next logical question is whether women are also more vulnerable to chronic traumatic encephalopathy, or CTE, a neurodegenerative condition that may be linked to concussions. Several U.S. women’s national soccer team players have recently pledged to help find out by donating their brains after they die so research can be done into CTE. Brandi Chastain was the first, and now Abby Wambach and Megan Rapinoe have joined in too. I hope that it is many decades before their donations happen. Professional wrestler Chyna’s donation came tragically early. The WWE star died unexpectedly in April at the age of 46, and her manager reported that her brain has been donated to famed neuropathologist Bennet Omalu to look for signs of CTE.

I smashed my face in a bike wreck when I was 16, losing consciousness and breaking my jaw in two places. Whenever I find myself at a loss for a particular word or forgetting where I left my phone, I wonder if that old head injury is to blame and worry that I could be losing my mind. That’s what’s so difficult about uncertainty — in the absence of knowledge, we create our own stories, and I, for one, tend to expect the worst. More research in this area could help set my mind at ease, or at least give people like me a clearer sense of what’s in store and what we might do about it.