It could be just him. People have these conditions that they can't stay still, baccho me bhi hoti hain.
Some could have it due to stress anxiety and kai bina reason ke bhi aise ho sakte.
As far as I know we should not make these people(especially kids) to supress this usse aur anxious ho jate hain. Instead unko busy rakho in some physical activity which requires mental stimulation too. For eg Samarth wouldn't be moving like that if he is concentrating on something like usko koi house activity ya task me dekhna.
I've seen addicts act jumpy and fidgety like him. Maybe it's cigarettes? He seems calm sometimes, and other times he looks like he's anxious to be somewhere else.
Whatโs up with his constant shoulder shrugs??? Creeps me out