Imagine leaving the hospital after a stroke. You spent days or weeks in acute care, surrounded by nurses, physiotherapists, and machines measuring every signal your body gave off. Then you go home. A folder of exercises sits on the kitchen table. Your first outpatient appointment is in two weeks. And between now and then, the most critical window for brain recovery ticks quietly past.
This is the reality for most stroke survivors worldwide. The science is clear that intensive, early rehabilitation produces the best outcomes. But the system, as it exists, cannot deliver that intensity to people once they leave the hospital. Outpatient slots are limited. Therapist time is expensive. Home programs go unpracticed because repetitive exercises without feedback are hard to sustain.
The Problem With Repetition Alone
Traditional rehabilitation has always understood that repetition matters. The arm that practiced hundreds of reaching movements in the clinic generally recovered faster than the arm that rested. But repetition alone is not the whole story. What the research has consistently shown is that the brain responds not just to movement, but to movement paired with intention.
Going through the motions of an exercise while your attention is elsewhere produces weaker neural changes than performing the same movement while genuinely trying to move. The brain is listening for both signals at once. When it hears them together, something more powerful happens. When it only hears one, the gains are smaller than they should be.
The Science We Built On
In 1949, neuroscientist Donald Hebb described a principle that would shape decades of brain research: neurons that fire together, wire together. When two brain cells are active at the same moment, the connection between them strengthens. Repeat that pairing often enough, and the connection becomes lasting.
For stroke rehabilitation, this matters enormously. A stroke damages the pathways connecting the brain's intention to move with the body's ability to carry out that movement. Rebuilding those pathways requires the brain to hear both signals, the intention and the movement, close enough together that it can start to associate them again. The research points to a window of roughly half a second. Within that 500-millisecond gap, the brain is primed to rewire. Outside it, the opportunity is weaker. Sync is designed entirely around this principle: every session keeps motor intention and motor execution in sync, which is also how the platform got its name.
How Sync Works in Practice
Using Sync requires an iPad or a laptop and a webcam. Nothing else. No wearables, no clinic visits, no expensive equipment shipped to your home. You open the app, choose an exercise, and the camera starts watching. From there, three things happen together.
Movement. The camera tracks your body in real time using the same computer vision technology that powers research-grade motion analysis. It sees 33 body landmarks and 21 hand landmarks per hand, giving it a precise picture of how you are moving. When your movement matches the target, the game responds. When it does not, the feedback guides you toward better form. Every repetition is measured, scored, and stored so your therapist can see how the week went.
Speech. Aphasia, the loss of language after stroke, affects roughly one in three stroke survivors. For many of them, the hardest part is not finding words in the moment but practicing without a therapist present. Sync's speech module uses AI to assess pronunciation, fluency, and articulation in real time, giving patients honest, immediate feedback across a range of exercises they can complete independently, as many times a day as they want.
Cognition. Recovery is not only physical. Attention, memory, and processing speed are often affected after stroke, and they respond to the same principle of engaged, structured practice. Sync's cognitive exercises are built into the same game framework, so the patient is always doing something that feels purposeful rather than clinical.
What We Hope It Changes
We built Sync because we believe that hospital-grade rehabilitation should not end at the hospital door. The neuroscience is accessible. The technology to apply it at home now exists. What has been missing is a platform that brings these two things together in a way that patients actually want to use every day.
We are not trying to replace therapists. Therapists understand their patients in ways that software never will. What we want to do is give therapists a tool that extends their reach, so the work done in a clinic session continues at home, every day, with enough structure and feedback to actually matter.
Stroke recovery is long. The window for maximum change is short. We built Sync so that window does not have to close while someone is waiting for their next appointment.
The Sync Team, March 2026