American football involves constant collisions. That type of research suggests that even without a “concussion” the same type of damage can occur from repeated, more mild collisions.

Cycling seems like a different order entirely, it’s extremely unusual for a cyclist’s head to hit anything and only happens during an accident or mishap.

Soccer is a good example. You are rarely concussed from heading a soccer ball, but there is some evidence that players may suffer brain damage from from repeatedly heading the ball.

https://www.sciencedaily.com/releases/2018/04/180424112923.h...

45 headers in two weeks were enough. Holy Jesus! Thank you for bringing this to my attention. I probably won't heal but maybe I'll protect from damage.

> They found linemen with the same issues despite no concussion history.

With no reported concussion history.

Reported can mean many things. If I was asked in such a study I would bring up the 7 our situations I know of where I even suspected I might have had a concussion, mostly snowboarding related actually (with helmet), odd given I also played 9 years of football and 9 of Aussie rules. None of them with concussion effects other than maybe I'm done for the day (you tend to take bigger falls when you are tired).

Also seen enough concussions and evaluations to be able to identify those exhibiting obvious symptoms tho I'm not trained in it.

I would let the people running the study decide how to classify them.

Its also not like there is a standard "reporting" form for concussions. Especially further back and esp if you had a team doctor.

I think the parent is implying that all experienced american football linemen have had many concussion situations, so the whole idea of splitting them in to "concussion history" and "no concussion history" can only reflect how the events are reported, and not whether their heads have been smashed repeatedly.

It depends on the definition of concussion used. If you go broad enough everyone likely has had multiple minor ones if they were ever on a playground or ambulatory (walk into wall, accidentally hit in head, fell, etc).

Maybe also of interest in that regard is the movie "Concussion" with Will Smith about the story of Dr. Bennet Omalu.

https://en.wikipedia.org/wiki/Concussion_(2015_film)