Head position when running fast

For some reason, when I run shorter distances at top speed (ie. open 5km or 10km races) i tend to tilt my head skyward during the last half of the race as i’m trying to hold my pace. I realize that this is something that many people do to some extent but it seems for me it’s pronounced…to the point where people are pointing it out.

For some reason i have trouble avoiding this. During my last 10ki tried to level my head but it feels like its affecting my pace when i do so - something about my breath, so i gave up. Anyway, i’m wondering if

(a) there’s a good reason that this happens - ie. weak muscles, genetic, running beyond my limit, etc.
(b) if there’s anything i can do to fix it, and
(c) if it’s having an impact on my time.

On average i’m about 38min for a 10k.

This seems like a troll post because it’s so ridiculous but something that i’ve thought about asking for a while.

Thoughts? Does anyone do this or see this?

BQ

I think it’s fairly common. You see it at a lot of high school track and cross country races as kids are running down the homestretch and almost out of gas. Not sure the reason why

Ever see Chariots of Fire? The Eric Liddell character would do this when he got up to speed.
Personally, I used to do this when I was a faster runner, and was trying to get more air down m windpipe as I was nearing the edge of full exertion. Now that I’m a slower runner, I don’t do it anymore…but I’d rather be fast with my head tilted back than slower with “good form”.