Sounds to me.like he is stimming. Some think stimming is good for.them i think if hes not hurting anyone why not let him do it.it may be helping him to be calm. My son has rocked on the couch sence he was 7 months old.at first we tried to redirect it but it only made it worse. He would at 1 play for ten min the come sit on the couch and rock,for twenty min.he did it up to 50 times a day. I rem a bad day he rocked for 45 mins,was a week before his diagnosis, some weeks are better then others he still at 4 rocks.

My daughter did this a lot when she was your son's age, still does this but it has subsided. To be honest nothing we tried - play therapist, teachers, OT, etc really worked, we just encouraged her to do it in "private" because of boundary issues with others. We had to teach her about imposing her behaviors, while being soothing, on others wasn't acceptable. It fell under the "manners" category. In her room we let her have free reign of this habit. I will admit - it was disturbing, but therapist reminded me "Bonnie remember when you prayed for her to be verbal?"

How old is your son?

Omg my girl is playing movies in her head about Godzilla she writes scripts and draws scenes for the big production she will be producing and directing one day
These two would have much to talk about