I'm not sure if this is the same thing, but my DS (now 8) would do arm-spinning (imagine windmills) when he was about 4-6 and in overly-stimulating environments. It showed most when he was doing something like playing soccer -- lots of noise, lots of people, environment he wasn't used to.... He'd run after the ball spinning his right arm the whole time. Sometimes we'd also see it in classroom-type settings during very active and/or social times.
Although he has some OEs (and anxiety), he is definitely not on the Autism spectrum -- that's according to DH & I, his teachers and the pscychologist who evaluated him for anxiety, etc...
DS is very much a fidgety kid, but we no longer see the arm-spinning. Frankly, now it seems to have changed in sports settings to him tripping over invisible things every few minutes and rolling on the ground before he gets up. He's a hoot to watch play basketball. It looks like the invisible man is fouling him over and over again!
