Whether some American football players suffer from concussion after a hit on the head may depend on the number and severity of head impacts that they sustain in the days, weeks, and months leading up to the concussion, rather than a single large head impact. This is according to Brian Stemper of the Marquette University and Medical College of Wisconsin in the US. Stemper is lead author of a study on concussion in college football in the Springer-branded journal Annals of Biomedical Engineering. The findings provide further support for policies that try to limit head impact exposure during football training and games.
