- Shortcut
- The trunk leans forward.
- What it skips
- Straightening the elbow.
Keeping the trunk still during reach training improved elbow extension and arm function.
Michaelsen et al., Stroke, 2006 · randomized trial
Physical AI for human movement
Hasten catches the shortcut your therapist or coach picks as it starts, and cues the fix mid-rep: a sound, a tap or a pulse to the muscle. It runs on the phone you already own, with a watch as an option, and reads movement down to the muscle. For therapists, every rep at home becomes measurable progress and remote monitoring your clinic can bill for.
Every movement is learned by repetition: relearning to reach after a stroke, a child learning to catch, an athlete grooving a squat, a person with Parkinson’s taking bigger steps. The expert sees a fraction of those reps. The rest happen alone, and the body quietly finds a shortcut. The rep gets done. The shortcut becomes the habit.
Keeping the trunk still during reach training improved elbow extension and arm function.
Michaelsen et al., Stroke, 2006 · randomized trial
Making the weaker arm do the work improved arm function, with gains still there a year later.
EXCITE trial, Wolf et al., JAMA, 2006
Movement asymmetries at landing predicted a second ACL injury in athletes returning to sport.
Paterno et al., Am J Sports Med, 2010
Lang et al. 2009 · Birkenmeier et al. 2010
Of 100 patients given home exercises
Adherence: Yalew et al., Patient Preference and Adherence, 2022 (300 outpatients, 35.3% adherent)
Each uncorrected rep reinforces the shortcut. Corrected in the moment, the same reps build the right pattern instead.
people in the US live with Parkinson’s, MS, a brain injury or a spinal cord injury. About 800,000 more have a stroke every year.
60% still struggle with their arm six months or more after a stroke.
school-age children has a coordination disorder that makes everyday movement hard to learn.
Therapy is weekly. Practice is meant to be daily, at home, with no one to correct it.
sports and recreation injury episodes in the US every year.
Prevention works only when the reps are done right, every session.
Parkinson’s Foundation · National MS Society · CDC · NSCISC 2023 · Engström 2012 · Wiggins 2016 · J Orthop Res 2018
Every unwatched rep is practice for the shortcut. The fix has to happen during the rep, wherever people practice.
One quiet correction during the rep, while the movement can still change. No screen to watch, nothing new to buy.
The phone camera tracks the whole body, joint by joint, and compares every rep with your own baseline, not a textbook.
It’s designed to flag compensation while it is building, a fraction of a second before it shows.
A tone from the phone or earbuds, or a tap if you wear a watch. You correct without looking away from the movement.
Angles show what the body did. Muscles show why. Synthetic sEMG estimates the electrical activity of the muscles, the signal electrodes on the skin would record, from ordinary phone video.
We start with the large surface muscles of the shoulder and arm: upper trapezius, deltoid, biceps and triceps. The same model extends to the legs and trunk for walking and sport.
The three levels run from active to passive, and the right one depends on who is practicing. Someone who can make the movement but drifts into a shortcut needs only a signal: a tone or a tap, and they make the correction themselves. That is active learning, the kind motor-learning research links to skills that last. Someone who can’t yet make the movement gets help at the muscle. Every level fires at the same moment, as the shortcut starts, and Hasten steps back toward active as control returns.
The default. A tone, or a two-word prompt like “sit back”, from the phone speaker or earbuds, so it works with nothing but the phone. It fires at compensation onset, mid-rep, at most once per rep, and suits people with reduced sensation in the hands and anyone who prefers to hear it.
Optional, for people who wear a watch. A short haptic pattern, with its own pattern for each shortcut: a single tap can mean “sit back”, a double tap “drop the shoulder”. It fires at the same moment as the tone, works silently and keeps your eyes on the task, not on a screen. Best on a wrist with good sensation.
Hasten reads the muscle that should be working, from video (synthetic sEMG) or from sEMG electrodes in the clinic, and triggers surface electrical stimulation (sEMS) on that muscle just before the movement needs it: the triceps to straighten the elbow, or the muscles around the shoulder blade so the trunk doesn’t have to lean. It builds on EMG-triggered stimulation, an established stroke therapy, and runs through partners’ cleared stimulators, in the clinic first.
Every frame, synthetic sEMG estimates how active the triceps and the muscles around the shoulder blade are.
A first reach after a stroke. A child’s first clean catch. An athlete’s thousandth squat. A bigger step with Parkinson’s. These are where we start, not where we stop. Wherever a body repeats a movement, it can learn a shortcut, and Hasten can catch it. Every new movement needs new examples, never a new engine.
About 800,000 strokes a year in the US. Around 60% of people still struggle with their arm six months or more later.
For Neuro rehab clinics prescribe it during therapy. Patients continue on their own plan after discharge.
About 1.1 million people in the US live with Parkinson’s. Movements shrink and slow over time, and big, deliberate practice every day is what keeps them.
For Neuro and movement-disorder clinics, and people practicing big-movement programs at home.
Nearly 1 million people in the US live with MS. Weakness, spasticity and fatigue change how people walk and move, often within a single set.
For Neuro rehab clinics and MS centers, between sessions and at home.
An estimated 5.3 million people in the US live with a disability related to traumatic brain injury. Balance, coordination and walking come back through daily practice.
For Brain injury programs, including military and veterans’ rehab.
About 302,000 people in the US live with a spinal cord injury. After an incomplete injury, practice decides how much movement comes back.
For Spinal cord injury programs, and home practice after discharge.
Developmental coordination disorder affects 5–6% of school-age children. Daily skills are practiced at home, with no one correcting in the moment.
For Occupational therapists and families, between OT sessions.
About 1 in 345 children in the US has cerebral palsy. Therapy goals are practiced at home every day, between sessions.
For Pediatric physical and occupational therapists, and families.
About 1 in 640 babies in the US is born with Down syndrome. Low muscle tone slows motor milestones, and practice is what builds them.
For Pediatric physical therapists and families, from early intervention on.
About 2% of children still walk on their toes at age five and a half. Heel-first walking and calf stretches make up the home program between visits.
For Pediatric physical therapists and families.
Speed and power come from timing, and small timing faults repeat in every rep. A coach sees some of them. Video shows them after the rep is over.
For Athletes, coaches, academies, and sports platforms that license the engine.
Technique faults repeat in every set, and a coach can watch only some of them. Video review comes after the rep is over.
For Athletes, coaches, and fitness platforms that license the engine.
Injury-prevention training built around landing, cutting and running form cuts ACL injuries by about half. It works only when the reps are done right, week after week.
For Team sports, academies and sports physios.
After an injury, the body protects the hurt side without being asked. About 23% of young athletes who return to sport after an ACL reconstruction injure an ACL again.
For Sports physios, orthopedic rehab clinics, and athletes after discharge.
Every rep your patients do at home is coached, logged and measured. You see the shortcut fade week by week, and that same monitoring is work your clinic can bill for.
Average 2026 Medicare rates for the RTM codes a musculoskeletal program typically bills each month. Rates vary by region and payer.
At $94 per patient per month (98977 + 98980). Eligibility depends on the payer and on program and device requirements.
Camera apps check generic form. Wearables and labs are precise, but they need equipment and a visit. Hasten is built around the shortcut the body takes in each movement, and corrects it while the rep is still happening, anywhere.
| Criterion | Camera exercise appsRehab, fitness and back-care apps | Wearables and lab systemsSensor suits, gloves, motion-capture labs, FES devices | Physical AI for movement |
|---|---|---|---|
| What it measures | Joint angles against a target position | Signals from body-worn sensors or lab cameras | The whole movement, plus muscle activity estimated from video (synthetic sEMG) |
| What counts as an error | Generic form deviation, the same for everyone | Targets set per device or per lab session | The specific shortcut for each movement, measured against your own baseline |
| When feedback arrives | After the error is visible | During the session, or in a report afterwards | As the shortcut starts, mid-rep |
| How you receive it | Screen or voice, which pulls your eyes away | On the device, or from the coach or clinician later | A sound or a tap, then closed-loop sEMS on the muscle |
| What you need | A phone | Equipment to buy, fit and charge, or a visit to a lab | The phone you already own; a watch is optional |
| What the therapist sees | Reps and adherence | Device logs or lab reports | Compensation rate per session, reps and practice days |
Across rehab and sport, independent studies point the same way: catch the movement while it happens, cue it through the body, and the right pattern takes hold. Hasten brings those findings together in one engine.
trunk compensation when patients got real-time feedback from a smartphone camera, in a randomized trial of 55 patients.
Journal of NeuroEngineering and Rehabilitation · 2026 Sport · technique −17%knee load linked to ACL injury after individualized feedback on knee alignment during cutting, in 48 handball players.
International Journal of Sports Physical Therapy · 2024 Sport · training −50%in ACL injuries with injury-prevention training built around landing and cutting, pooled across eight meta-analyses.
Journal of Orthopaedic Research · 2018 Muscle · stimulation 2×larger arm-function gains when muscle-signal-driven rehab added electrical stimulation, across 13 studies and 330 stroke patients.
Frontiers in Physiology, meta-analysis · 2023 Camera · biomechanics 1 videofrom a single smartphone now estimates 3D movement and joint forces with clinically meaningful accuracy.
OpenCap Monocular, Stanford · 2026 Touch · rehab 35 studiesreviewed on vibration cues for upper-limb rehab: touch may support recovery, most when paired with active practice.
Frontiers in Bioengineering and Biotechnology · 2026Clinics and therapists, coaches, patients and parents, researchers, investors, and people who want to build this with us: if you care about how people move, we want to hear from you. Tell us who you are and what you have in mind.
Or write to us directly: assaf@hasten-ai.com