For the National Football League, the news on head injuries gets worse and worse. New research that examined the brains of 91 deceased football players found signs of a disease called chronic traumatic encephalopathy, or CTE, in 96 percent of them. This is in line with much other evidence that the hazards of professional football extend well into players' retirement.
Notably, the study also found that 40 percent of the afflicted had been linemen, players who get hit on almost every play. This bolsters previous evidence that repeated minor blows to the head could be more dangerous, over the long term, than the single violent hits that get more attention. And it confirms that confronting CTE will require ambitious changes to football programs at every level.