My friend has something very very similar sounding,

It turned out to be slight cerebral palsy, When he gets excited or gets "involved" in something which distracts him from his body, his right hand often curls an points backwards and one of his legs will be turned inwards slightly.

Its very hard to notice and I was friends with him for 3 years before I even properly realized

I'd noticed it before but had never paid any attention.

It had also given him the TIIIIINYiest, slightest speach imprediment but you wouldn't really notice - So I think it effects his mouth sliiightly too.

Don't worry, See a doc and get a more definate answer.

Don't get wound up or paranoid, get it checked!

All the best,
Jonny