Step Doctor scores your walk, the Timed Up and Go test (iTUG) and the SPPB from a short phone video. No sensors, no wearables.
Availability
Live in South Korea and the United States. Now rolling out: Japan.
Live
Available in the App Store and Google Play
Live
launched 2 weeks ago
Now rolling out
Launching now
Where next?
We're rolling out very actively, and the countries people ask for move up the list. Tell us where you are. Takes one second.
Accuracy from our internal validation, and how fast results come back.
Trusted by leading institutions
Three tests, one phone
Stand the phone up, follow the on-screen and spoken cues, and Step Doctor records and scores the test for you. Results come with a 3D replay, a PDF report and exercises picked for what needs work.
Walking test
Walk toward the camera for a few seconds. Step Doctor measures walking speed, cadence, stride length and left–right balance, and gives a 0–100 gait score.
Needs attention · under 60 · Fair · 60–69 · Good · 70+
Example: a real walk, score 88.
Mobility and fall risk screening
Stand up from a chair, walk 3 m, turn, walk back and sit down. Step Doctor times the whole test from the video and grades each of its six phases against published reference values. Timed this way, it's an instrumented TUG (iTUG).
Under 10 s · 10–13.4 s · 13.5 s or more
Example: a real iTUG, 8.7 s. Graded phases: stand up, walk out, turn, walk back, turn to sit, sit down.
Step Doctor supports screening and monitoring. It doesn't diagnose, and results should inform, not replace, clinical judgement. The science behind the scores →
Features
Spoken instructions in English or Korean walk you through the iTUG and SPPB, so you can record yourself without help.
No sensors, wearables or lab. Stand the phone up, calibrate the camera once and walk.
Watch every result move in 3D: your walk, each iTUG phase, each SPPB balance stance.
A report for each test, ready to share with your therapist or family.
Ask about your results in plain language and get answers grounded in your numbers.
A fresh mix of exercises after every result, led by what needs the most work.
Trends for every test in one place, so you can see what changes.
Encrypted in transit and at rest. Videos are deleted from our servers after about 72 hours.
Put the phone where it can see you, calibrate the camera once, and the voice guide takes it from there. The video is analysed in the cloud and comes back as results you can follow over time.
Our own models lift an ordinary phone video into a 3D walking body.
Speed, cadence, stride and step timing are computed from how it moves.
Beyond a single score. See when each foot lands and leaves the floor, and how
the left and right sides compare, step by step.
Each report shows your results against their reference ranges,
with guidance on what to work on.
Our quality management system has been independently audited and certified by Kiwa Korea, an accredited certification body.
Certification covers AICU's quality management system and is maintained through ongoing surveillance audits.
Start free, then choose a plan or buy credits when you need them. Each test uses credits, and prices are shown in your currency.
Perfect for individual patients.
Save 17% annually
Built for clinicians and care teams managing multiple patients.
Save 17% annually
Buy credits when you need them. No monthly commitment.
Integrate gait analysis directly into your application. Full API access is included in the Professional plan.
Questions
Step Doctor is a gait analysis app for iPhone and Android, made by AICU. It analyses walking and balance from a short phone video and runs three tests: AI gait analysis, the Timed Up and Go test (iTUG) and the Short Physical Performance Battery (SPPB).
No. You need the phone, something to stand it against, a few metres of floor and, for the iTUG and the SPPB chair stands, one chair. Voice prompts guide you, so you can record yourself without help.
A standard mobility test (Podsiadlo and Richardson, 1991): stand up from a chair, walk 3 metres, turn, walk back and sit down. Step Doctor runs it as an instrumented TUG (iTUG): it times the test from the video and splits it into six phases (stand up, walk out, turn, walk back, turn to sit, sit down), each graded against the reference values of Mirelman et al. (2014). A total under 10 seconds is typical; 13.5 seconds or more is a widely used fall-risk cut-off (Shumway-Cook et al., 2000).
The Short Physical Performance Battery (Guralnik et al., 1994) scores balance, gait speed and five chair stands, 0–4 points each and 0–12 in total. Step Doctor runs the whole protocol hands-free and scores it from the video. The usual bands are 0–3 (severe limitation), 4–6 (moderate), 7–9 (mild) and 10–12 (minimal).
No. Step Doctor supports screening and monitoring. It doesn't diagnose, and results should inform, not replace, the judgement of a healthcare professional.
The app is free to download. Each test uses credits: new accounts get welcome credits, and plans and credit packs are listed under Pricing.
English and Korean, including the voice guide.
Support
Stuck recording a walk, or have a question about your results or account? Call us during Korean working hours, or message us any time.
Mon–Fri, 08:00–20:00 (Korea time)
We speak
Message us any time.
Outside call hours, replies may be slower.
For anything that needs a longer answer.
No lab. No sensors. Record a short video in the Step Doctor app and get objective measurements of how you walk, stand up and keep your balance, for yourself, your family or your patients.
