How the metrics are defined

The video pipeline measures geometry and timing in the image plane. True edge angle and foot pressure cannot be recovered from video — those belong to the sensor version, and this library does not pretend otherwise.

Peak inclination: The largest angle between the body axis and vertical within a turn. Higher is more aggressive. An off-axis camera reads low, so only compare shots from the same position.
Symmetry: The ratio of peak inclination between left and right turns, times 100. 100 is perfectly symmetric; below 85 usually means a clearly weaker side.
Rhythm variation: Coefficient of variation of turn duration. Lower is steadier; under 20% counts as stable.
Angulation: Torso axis inclination minus leg axis inclination. A positive value means the torso stands more upright than the legs — compensation from the upper body. Undefined at the moment of edge change.
Edge-change rate: Rate of change of inclination at the zero crossing, in degrees per second. Higher means a crisper entry into the turn.
Deepest knee flex: Minimum of the hip–knee–ankle angle. 180° is fully extended.
Centre-of-mass travel: Distance from mid-hip to mid-ankle, divided by the median leg length across the clip. Dimensionless — used to read the timing of loading and release.
Shoulder–hip separation: Angle between the shoulder line and the hip line. Strongly view-dependent; only meaningful between shots from the same camera position.