I found myself looking at FN Barrick instead. 
Yeah, she ain’t bad. She can touch up my bulkhead anytime.
OK, I think I’ve finally come up with a plausible explanation for this. I just learned about lymphedema, a medical condition in which limbs (or parts of them) become enormously bloated by fluid retention. Googling for pictures of the condition reveals a lot of photographs which very closely match what I saw.
Maybe this zombie was descended from \Alley Oop:
For those wondering: Popeye’s first appearance in Thimble Theater preceded Alley Oop’s by three years. And Popeye had the ridiculous forearms (and calves) first.
Matthias Schlitte’s forearm measures 46cm and has led him to glory in the world of arm wrestling…
Matthias can win in his weight class, as he is rather puny except in the one fore arm… where he has large functional muscles.
Most other winners have larger biceps … as in upper arm is larger than the forearm…
Some obese people may put the fat on their forearms… they might lose weight from their belly and legs, but not thin out at the arms… thus keep thick arms…
Here’s a boy … maybe its just baby fat… Maybe it means they did no excercise, they’d have puny arms unless they had such excess fat
lymphedema is a possibility - which means lymph fluid is causing the swelling,
it could be lipedema, it would probably affact their lower legs too, … which means unusual fat deposit.
In any fat problem, they probably would avoid becoming obese around the torso so as to keep their limbs mobile… you can’t get fat if you can’t eat… when they have a problem with their forearm, they stop eating…
here’s an example of someone who lost weight after a developing a problem… NSFW … NSFSP (sane people)
http://www.scielo.br/img/revistas/rcbc/v41n1//0100-6991-rcbc-41-01-00018-gf01.jpg
Guy I knew back in the SCA who made riveted ring mail had arms like that (mostly his right arm, for obvious reasons, which was weird.)
ETA - sorry, just noticed this is a zombie. But, I mean, I DID know a guy who DID make riveted mail and DID have weirdly huge forearms. So it’s not like it’s not relevant.
OK, zombie thread and all but the power tool commercial in that link, featuring Mr. Schlitte, is pretty funny. He obviously has a sense of humor about his unusual gift. The boat scene made me laugh out loud.
It is what it is.
[Popeye] I wants me brains.[/Popeye]
I saw a guy in Toronto with lymphedema (of the legs) about an hour ago.
Since this is already shambling about, there’s no harm in adding another profession that develops massive forearms: baker.
My brother baked for Dunkin’ Donuts, and then for a local grocery store, and all the time spent kneading dough and working with just his hands and the flex of his wrist gave him forearms that were big and as hard as rocks.
His shorthand for describing how his arms looked back then is to laugh like Popeye. 