baby finger movement

hello, my question is regarding my son's baby finger. we have noticed that his baby finger moves. We thought at first it was a nervous habit. Now it seems like the whole hand is involved. We have asked him if he feels he can stop it.  He says he likes to do it. But, we believe he just is not sure what we are asking him. He is six. Our son otherwise is healthy. We have not seen our primary doctor yet. What do you believe would be tests we can perform to make sure this is nothing more than a habit he has picked up. Thank you so much for your attn. Lisa J  PS its his left hand

[Dr Vinod]

You should watch it while he is asleep or not concentrating on his fingers like while he is eating, playing etc and you can confirm it then. If it happens spontaneously then just go for a routine check up near your Paediatrician. Take care!

[AAJ972]

Dr Vinod, thank you so much for writing back and giving us the direction we need to take. We'll do just as you directed. Thanks again AAJ972