Xan likes swimming, and swinging, and jumping in bouncy houses. We've got one of those exercise balls and he'll fling himself at it to bounce up and down on the edge of balance between control and the emergency room. He loves to grab your hands and spin you both around in a whirling circle until you're about to fall down or throw up - and then he'll leap in the air for some extra centripetal oomph. After only a few broken furniture pieces and almost broken bones, he has decided doing this in cramped places (such as the living room) isn't the best idea. (...usually, but it pays to be on your guard.)
What do all of these have in common?
Xan used to take physical therapy in Birmingham. We stopped when he really started resisting it, since driving an hour to fight for forty-five minutes seemed like a bit of a waste - we could save a drive and be yelled at here just as easily. One of the times we went, his therapist showed us some calming tricks that involved locking a joint, knee or elbow, and gently thrusting down on the foot/hand. I'm probably missing some critical step here, so don't try this at home unless some therapist shows you the trick.
The therapist explained that many autistic kids have, for lack of a better term, a strangeness of their own bodies - feeling out of place in their own skin. Could be that sensory overload again, could just be a mental disconnect that's an offshoot or a result of the differences in their brains, may be an aftereffect of everything else they go through. We don't know yet. But doing that joint-lock/soft thrusting helps them recenter, feel better. A kind of reset button. If you've seen an autistic child hit themselves lightly with a hard object on a joint (Xan likes books and elbows), that may be doing the same thing - a contact that helps realign them.
What does jumping in bouncy houses, being whirled in the air, swimming and swinging have in common?
Every one has that fleeting second or two of ... disconnect. Free of gravity, of weight, of contact, of everyday being. Maybe those blinks of freedom help them get away from what they have to go through all the time.
For a few pauses, they are free of their everyday heavy weight.