Welcome to BYC.
So sorry you are having problem with your chick. The swelling is consistent with a full crop, but IMO would be unusual in a young chick unless it is eating litter, bugs, treats - anything other than chick starter crumbles. Or has a problem lower in the GI system. More information would help and photos always help.
How old is the chick? What are you feeding them, what other than food do they have access to? Have you seen the chick in question eating the bedding/litter? Have you examined the chick well to rule out limb or other obvious problems?
Most chickens seem to sit when they are ill or injured and the primary cause is not always obvious.
Chicks in brooders awaken and eat nearly 24 hours a day. They have to learn what is food and what is not food. But impacted crops are not a usual occurrence in the really young babies.
Please consider the questions and post under emergencies. Hope this is something that can be corrected.