The panel of experts says football helmets may not be as protective as we thought.
While the opponent can seem intimidating, perhaps a more formidable foe is the "culture of resistance" young athletes face when it comes to speaking up about head injuries.
"They feel like they're letting their letting their teammates down," said Dr. Robert Graham of the Institute of Medicine.
Graham chaired a committee of experts convened by the Institute of Medicine.
The panel urged a change in sports culture to treat blows to the brain as thoroughly as visible injuries.
"Getting a second concussion while recovering from the first does appear to result in a more significant injury that takes longer to recover," Dr. Arthur Maerlender of Dartmouth-Hitchcock Medical Center said.
The experts said helmets are crucial in helping protect against fractures and bleeding in the brain; but there is little evidence helmets do anything to protect against concussions.
"Until we have this fundamental data, we cannot determine whether a given design of a protective equipment can mitigate concussion risk or not," said Dr. Kristy Arborgast of Children's Hosptial of Philadelphia
Helmet manufacturers are aware.
Consumers can't even access the website of helmet maker Schutt without first acknowledging that no helmet can prevent a concussion.
Although it's boys' football that gets the most attention when it comes to concussion risk, the report found rates were higher among female athletes.
Concussion rates are higher for boys in ice hockey, football, lacrosse, wrestling and soccer.
Among female athletes, rates are higher in soccer, lacrosse, ice hockey and basketball.