push ups good idea, but i think he would tire out very quickly...there is no real " outside"as in a garden, the only times he goes out is with his friends ( we live in a small village and the kids just go play together behind the school unsupervised) and he knows better than to stim when his friends are around ( except some light jumping when excited), i think he just lets go when he's safely at home, and after school is the worst. as i say the only place out of my eyesight is his bedroom, but that's a bit rude to tell someone to go do what he does somewhere else just because it gives you a headache, especially when they have been cntrlling themselves all day at school, and even if he's my son i feel he has the same right of jumping around as i have to read a book, after all we're at home. BUT: i still can't stand it lol.....
so maybe the smaller motions would be good , but as he apparently indeed needs to be using all of his muscles at once, ( lol picturing this hahahha no it's not like he's some kind of electrified puppet...) just jumping a lot.....and he's not aware of what he's doing so much. if i ask he'll say "nothing"...why do you jump? huh i dont know. ok then. it's so constant it's just his natural way to be at home, so i don't know how i could ask him to do it differently....
ps: if i decided to use your visual reminder thing, i would have to physically turn him around, have him face the sign,wait until he actually looks at it, and that doesn't even mean he would obey.