Twitchy kitten?

My 5 month old kitten often twitches when he's relaxing or after you pet him. Its his sides and back that twitch, never anywhere else. Other than that, he's perfectly healthy and acting just like always.

Is this something I should be concerned about?

It doesn't sound concerning to me- just like he's having some pretty active dreams! 

 However, if you are concerned about it or think that something seems off it's worth it to follow up with your vet just to be on the safe side. 

My girl has always been twitchy. If you touch her back lightly it twitches. She also used to sleep so deep when she was little her whole body and face would twitch. When they're babies I feel like they relax more and sleep deeper. I think he's fine but if you're worried it never hurts to check it out (except the pockets lol)