1. Your walk
How to record
- Prop the phone sideways at hip height, 3–4 m from your walking line.
- Walk past at your normal pace for at least 8 steps.
- For a second angle, film the same walk from in front with another phone. Clap once at the start where both phones can see it.
- Use slow motion (120–240 fps) if your phone has it.
Or try a sample:
2. Gait numbers
3. Fall-risk estimate
Where this fails
- Slow walking: speed from one camera read 47% high at 0.5 m/s, so a slow walker can look faster than they are.
- One camera inflates step-time variability 1.5–2.5×. Two cameras fused bring it to about 1.3× motion capture.
- Two phones keep separate clocks. Walking repeats every step, so matching the clocks from movement alone can land one step off (18 of 53 archive walks were ambiguous). With two uploaded videos, the page syncs them on a clap heard at the start. Without a clap it falls back to matching movement.
- The video score is calibrated on 12 nursing-home residents aged 75–99. Its best leave-one-out accuracy is 8 of 12, so it is shown but does not set the tier. Every accuracy interval reaches 0.5 (chance).
- No public dataset pairs walking video with recorded future falls, so nothing here is validated against falls themselves.
4. Pose overlay at heel strikes
5. Assessment and exercises
Claude is writing the assessment…