chick throwing head side to side and stretching neck Help????

[toetoe]

I have a chick that is throwing its head from side to side like shaking something off it's beck. It also is stretching it's neck out like it is trying to swallow something but can't get it down.
It is very slow in it's walk and just wants to get under mom. It is 21 weeks old.
It is drinking, put a little vitamins in it's water and has eaten a little chick feed but now it is been doing this stretching thing the past 45 min.

Dose anyone have any ideas???

 

[toetoe]

Before letting it go in the hen house with mom tonight I picked it up and felt it's throat. Between the top of the throat and the crop I felt a hard area like it was grit or something stuck in the throat. If there is something stuck there how would I be able to get it out?
It feels like if you put 4 or 5 grains of rice in the neck if a balloon.

Anyone have any ideas please.