I don't have T-rex arms, but if I did, it would be for a very good reason.
/One of my friends famously described me as a "neckless stump with legs for arms."
This wasn't nice, but when I use that description onstage to describe myself, it always gets a laugh, so I embrace it.
Anything for the laugh.
Another friend watched me golfing one day and described me as having T-Rex arms. Short and stubby.
I have since proven that my arms are appropriately proportioned to my body.
Sadly, the T-rex comment has stuck, so even though I have taken the measurements and proven him wrong, I still hear this less funny insult from time to time.
"The more dinosaurs we find, the more it is becoming clear that many theropods reduced their forelimbs. It is a recurring pattern," said Steve Brusatte, a paleontologist at University of Edinburgh
The purpose for these short, stumpy arms?
"I think there is good evidence that the arms got smaller as the head got larger, so the head was taking over many of the duties that the arms once had, like procuring and processing food. But they must have still been doing something, or else evolution would probably have just gotten rid of them, the same way snakes lost their legs when their legs no longer served a purpose."
So if I had short and stumpy arms (which I don't), they would probably serve some extremely useful purpose related to a larger head size (I do have a large head) that has yet to be determined.
All of this is moot, of course, because my arms are perfectly proportionate to my body in every way. Regardless of what my friends my say.