Why this app talks about confidence so much

Pose estimation from a single phone clip is genuinely useful, but it is not lab-grade. Camera angle, distance, lighting, and clothing all affect accuracy, and small position changes are exactly where measurement error bites hardest.

So this app measures several pedal cycles, looks at how consistent they are, and attaches a confidence band to everything. When confidence is low, it asks for a better clip or a human — it does not guess a millimetre.

If a tool gives you a precise-sounding number with no sense of its own uncertainty, be skeptical.