For me the upper c spine alignment must have been off after my horse bucked me off as a teenager. But no internet back then...to learn about these things.

After all the years later (30+) & repetitive job I got more aches & strains and noticed uneven shoulders, uneven hips etc .
see www.upcspine.com for more info on that part of it.

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http://www.upcspine.com/self.htm


And Sharon Butler's ( www.selfcare4rsi.com ) theory is the sticky fascia angle - which I think applies for me too.
I do have to loosen up most mornings and cold wet weather is the worst for getting going some days.

repetitive motion damages + sticky fascia + unevenness caused by off centered atlas/axis of the c1 c2