system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Do helmets prevent concussions? Why or why not?

Just doing some thinking and it just occurred to me for the first time in my dumb existence concussions are the brain rattling in the skull for XYZ reasons... but what can a helmet actually do for that?
gpt
They do. If you look at the design of a helmet, you'll see that they're designed to distribute force throughout the whole thing. When you get concussed, your brain is suddenly accelerated in a direction, so if the force that causes that is dispersed over a larger area, the damage will be negated or at least less.

Just a safety warning. If you ever get in an accident in which your helmet takes the brunt of the force, get a new helmet. They're only going to be able to do that once.