15.125 14.5.16 Smoothness y fluidez
La literatura de smoothness muestra que medidas basadas en jerk no son equivalentes y que LDLJ/SPARC poseen propiedades distintas [P45-R8, P45-R9]. En escalada se han utilizado jerk de cadera, inmovilidad y métricas de organización espacial [P45-R10, P45-R11, P45-R12].
| Métrica | Dominio | Fortaleza | Riesgo |
|---|---|---|---|
LDLJ |
discrete movement | dimensionless amplitude/time normalization | third derivative and noise sensitivity |
SPARC |
speed profile | spectral smoothness and temporal scaling robustness | requires uniform sampling and declared spectral threshold |
SpeedPeakCount |
speed profile | interpretable submovement proxy | threshold/filter dependence |
StopRatio |
attempt or phase | temporal organization | cannot distinguish rest, reading, control or failure by itself |
GIE |
route-relative hip/COM path | spatial organization used in climbing research | multiple formulations/reference envelopes; must version formula |
PathDirectness |
targeted phase | simple geometry | direct path may be mechanically or tactically inappropriate |
CorrectionCount |
effector acquisition | captures re-aiming | jitter can create false reversals |
PhaseTransitionSharpness |
boundary window | transition characterization | depends on phase and derivative profile |
Regla de publicación: Publish the metric name, exact formula/version, input signal, frame, window, filtering, sample rate and validity coverage. Never publish a generic smoothness score without these fields.
jerk is the third derivative of position
dimensionless jerk normalizes movement duration and amplitude
SPARC operates on a declared speed spectrumLa inmovilidad no es necesariamente mala fluidez. Puede ser lectura, reposo, estabilización o una restricción funcional; 14.4 y 14.3 deben aportar la interpretación temporal y mecánica.