What to look for in a kitten that accidentally took a smack

The kittens are 6 weeks old. We had the kittens in their bedroom, but momma kitty wanted to be downstairs with the rest of the family so we opened the door & stuck a piece of foam-core board in the doorway so she could get in & out without the kittens escaping. At some point, momma kitty decided she wanted to bring the kittens downstairs with her so she tried to jump over the board with a kitten in her mouth. She got over, but the kitten smacked into the board. I heard the shriek & went to check what had happened. The kitten was laying there (originally though she was seriously injured or worse because she was just sort of splayed out). After I picked her up she started sluggishly moving around for a minute before she started to wiggle like she normally does. She was playing around with the other kittens, but what should I keep an eye out for just in case?

Ouch I hope she'll be ok! I would look for her being lethargic, not eating, drinking or not using the bathroom. She will probably be ok but I'd just check her over to make sure she's not hurt. If she shows any signs that are abnormal, I'd rush her to the vet but I do hope she'll be ok!

I guess you could also take note periodically of the eyes?  We look for normal eye reactions in humans who have suffered concussion.  My guess would be unresponsive eyes need emergency vet, same as ER for humans.

How is the kitten doing today?

She's fine. Think she was just shocked from the impact.