system
Given the following post, respond as if you're commenting on Reddit:
human
[Star Wars] What's the purpose of elongating the back of the helmets?
gpt
Which ones? For stormtroopers it's probably the same for old suits of plate armour - the flare of the helmet can help deflect a descending blow away from the neck.  

For those guys on the death star it's a posture thing to stop them slouching in their chairs while they're on duty.