I think I was born to be in motion. I have difficulty resting when I’m at rest.
If I have to sit in one place long enough, I’ll cycle through dozens of postures without thinking about it. I slouch. I splay. I pin one foot under the other. I pull one knee up, then two, hugging my shins with a hand or arm. I sit on my foot, ankle or calf. I sit crossed legged, even on chairs. I put my elbows on the table, lean my head or chin on my hand, interlace my hands on top of my head. I perch on the edge of my chair, turn sideways, tangle my feet in the legs of nearby furniture.
The variations are endless but they have one thing in common–they orient my body to my surroundings. Without a steady stream of proprioceptive feedback, I start to feel disoriented and disconnected from my body. I feel lost in space. Confused. Physically disorganized..
When I’m at home, sometimes I just go lie on the floor to give my body a break from being upright. Because being upright requires figuring out where to put my hands and arms and legs and feet and often no sooner do I get that all sorted out than that restless feeling starts nudging at my leg or foot or spine and I need to move again.

It’s not that I can’t sit like a proper adult. I often start out sitting with both feet on the ground, arms relaxed at my side. In fact, in new social situations, I make a conscious effort to sit properly. Because I’m not four years old. I’m an adult–often an adult in a situation where I’m expected to look professional–and adults have very specific expectations of other adults in those situations.
Often what I come up with is a tense variation of typical “good sitting posture”:

Then my internal clock starts ticking and one of two things happens. If I’m in a formal setting, my body will grow more and more tense as I work to maintain a polite, socially acceptable posture. Then I’ll start covertly stimming, rubbing something between my fingers or twisting my hand in my pantsleg, something to counterbalance the tension that’s building up as I force myself to be still.
If I’m in comfortable or casual surroundings, it doesn’t take more than five minutes for me to start shifting around, searching for a more comfortable position. On an airplane, for example, I’ll start out sitting with my feet on the floor, book in my hand, arms close to my sides–typical polite seatmate posture. Soon, I’ll have one leg splayed out along the aisle or tucked under my opposite thigh. When that stops working, I’ll slouch and pin both knees against the seat in front of me or turn sideways and pull my legs up to my chest or fold one leg across the knee of the other, wedging a foot against the seat in front of me.
The fact that I’ll start stimming when I can’t freely change my posture often probably indicates that the positions I use to feel comfortable are in fact themselves a form of stimming.
Reset, Relax, Repeat
My body has a time limit on any one position. Even when I’m trying to fall asleep, if I don’t nod off right away, I need to keep changing position every ten minutes or so.
When I’m still, I have a gradual build-up of . . . I don’t know what. Tension? Discomfort? Disorganization?
I start to feel more and more uncomfortable until I have an uncontrollable urge to rearrange myself. Once I move into a new position, I’ll feel comfortable–momentarily at rest. Then, gradually, the discomfort starts building and soon I have to move again. Sometimes it’s only a matter of shifting back and forth repeatedly between two positions–a trick I used a lot at university to avoid adopting too many odd slouchy postures in class.
As important as the movement–and here’s where I think the particularly autistic aspect of this comes into play–is the position of my limbs. I almost always have one part of my body pinned, pressed, squeezed or wedged against or under something–either another body part or a piece of furniture. I think this deliberate pressure creates feedback that grounds me physically. It reminds me of where my body is in space and makes me feel safe in a way I can’t describe with words.
Physically, pressure equals organization.
Perhaps it’s like swaddling a baby. Mothers have been snugly wrapping up fussy infants for centuries. There is some science to back up the practice, suggesting that swaddling calms babies by enhancing motor organization and self-regulation. Once babies reach a few months old, swaddling is no longer beneficial or necessary because they have a reduced startle reflex and better-developed motor control.
Maybe there’s something very primitively calming about the kind of pressure I’m constantly seeking–a sort of localized form of swaddling.
Or perhaps it’s simply about feedback. Given my poor sense of interoception and my strong drive for proprioceptive sensory input, it’s not surprising that I need to intentionally create a steady stream of input to remind me that I physically exist.