Grade your running form from a phone video.
Easy / endurance pace - your everyday conversational running.
Ready when you are.
How to film it (this is 90% of the result)
- ·Treadmill, side-on - camera square to you, at hip height, a few metres back so your whole body is in frame.
- ·Nothing blocking your near leg and arm.
- ·15-20s of steady running at your normal effort, no looking at the camera.
- ·Good light - less motion blur means a cleaner read.
- ·Pick the matching profile: Easy for endurance pace, Fast for tempo / speed work.
What the numbers mean
Each signal maps to one thing you can cue. Green is the research-backed easy / endurance-pace range; outside it, here's what to change.
| What we measure | Ideal | If it's off |
|---|---|---|
| CadenceStep rate · reported | 160-185 spm | Your best cadence is personal and rises with pace, so we report it, not grade it. We only suggest a small (~5%) bump if you're overstriding. |
| Overstride (shank at contact)Where the foot lands | 0-12° | Shank well past vertical = foot landing ahead of you (braking). Land under your hips. |
| Knee bend at contactLanding softness | 18-30° | A soft, flexed knee absorbs impact. A near-straight knee is the stiff, overstriding landing we flag. |
| Forward leanPosture | 5-15° | A slight forward lean from the ankles helps. Bolt-upright brakes; folding at the waist is too much. |
| Vertical bounceBounce · info only | 0-5% ht | Roughly how much your hips rise and fall, as a share of your height. A rough read from one camera; reported, not graded. |
FAQ
Is my video uploaded anywhere?
No. The pose model runs entirely in your browser on your device - the video file never leaves your phone or computer. Nothing is sent to a server.
How accurate is it?
It's a form screening, not a lab gait analysis. Research on markerless 2D pose estimation (Stenum 2021) puts the error at roughly ±5-8° on knee and hip angles, with the ankle and the overstride read looser. It also only reads your camera-side leg reliably (the far leg is occluded), and finds the moment of footstrike to within a frame or two. That's plenty to catch the big patterns - a straight-knee overstride, folding at the waist - but for persistent pain or a big change, see a physio or coach who can film you in slow motion and 3D.
Why doesn't it grade my cadence?
Because the science - and our own data on 3,473 runs - says there's no universal 'good' cadence. Your best step rate depends on your height, your legs and your pace, and your body already self-selects close to its own optimum; the median runner sits around 164 spm, not 180. So we report your cadence for context but don't give it a green/red verdict. The one time cadence matters is if you're overstriding - then a small (~5%) bump pulls your foot back under you, and the tool suggests exactly that.
Does it work outdoors, or only on a treadmill?
A treadmill is best - you stay in frame the whole clip so we get many strides to average. Outdoors works if someone films you running on the spot toward-then-past a fixed camera, but you'll only get a few usable strides as you cross the frame. Treadmill, side-on, square to the camera, is the reliable setup.
My clip failed - what went wrong?
Almost always the film. Make sure you're side-on (lens square to you), well-lit, filmed far enough back that your whole body is in frame, with nothing blocking your near leg. Trim off the walking-on and stopping, or set the start/end seconds above.
100% private. Everything runs on your device - nothing is uploaded or saved on our side.