Symbolism, Imagery, Allegory
Antoine is a handyman. He's a little handsy. He's all hands on deck.
Nope. No amount of wordplay can disguise the fact that Antoine is just a sadsack facing a doozy of an existential crisis. But it does affect him… in a hands-on sort of way. (Hey-o!)
When Antoine starts feeling his philosophical "Nausea," the first place it strikes him is his hands. As he tells us:
There is something new about my hands, a certain way of picking up my pipe or fork. (2.3)
This makes sense, because Antoine's relationship with the world of material things around him is played out mostly through his hands, through his sense of touch. That's why when he starts to feel disconnected from the world, the feeling of strangeness happens mostly in his hands:
How unpleasant it was! It came from the stone, I'm sure of it, it passed from the stone to my hand. Yes, that's it, that's just it—a sort of nausea in the hands. (3.27)
At certain times, Antoine even loses track of what his hands are doing. It's as if they have taken on a mind of their own, as we find when he writes:
I opened my hand, looked: I was simply holding the doorknob. (2.3)
Antoine's major problem with existence is the fact that the physical things around him are cold and distant. Antoine doesn't feel like he has a meaningful connection with the world anymore, and the first symptom of this disconnection is the sense that his hands are completely alien to him.