A measurement experiment, not a validated fitness or medical instrument. No force, power, jump-height or injury diagnosis claims.
Open on your phone using HTTPS. Permission is requested only when you tap.
Waiting for real sensor data…
Choose a test
Keep the phone in portrait orientation. Each capture averages 2 seconds while you hold still.
5-second preparation, then recording. Keep still for the first 2 seconds as a baseline, then perform the test. An assistant can mark completed reps.
Enable sensors, choose your test, then follow the steps.
No recording yet.
Saved tests
Device-local storage only. Clearing browser data removes these results. Export JSON regularly; it includes raw samples and can be restored. CSV is for spreadsheets.
Accuracy checklist & other uses
- First measure a known 90° corner three times. Compare error and spread, not just the best result.
- Repeat each body test three times with identical placement, warm-up and posture. Record on video if possible.
- A split is a horizontal leg-direction estimate, not a full 3D hip angle. Keep the phone face-up and level; align its top toward each foot. Return to the first leg to check drift.
- Inclination can explore shin angle in knee-to-wall, trunk lean or a supported leg raise. It measures the phone segment, not a joint unless alignment and reference are controlled.
- Pull-ups, squats and calf raises: acceleration and manually marked tempo can be compared with video. A loose pocket measures phone movement too. Lanyard swing is not body acceleration.
- Balance or plank holds: motion RMS may explore repeatability of steadiness at the same placement. It is not a balance diagnosis or a technique score.
- No neck lanyard for pull-ups, climbing or dynamic movement: snag/impact risk. Use a secure pouch or snug pocket. Do not hold the phone during loaded pulls. Stop if uncomfortable.
No sensor-derived velocity, distance, power or automatic rep count in this first version: these need separate validation. Sensor data stays in this browser; exports contain your notes and browser information.