STRIDE-Z: A Windowed Persistent-Homology Descriptor of Bilateral Stride-Interval Geometry

Preprint and full reproducibility package. CLPR, a sliding-window Vietoris–Rips H1 descriptor of paired left/right stride intervals, was evaluated on a 1,200-series synthetic benchmark and all 64 records of the PhysioNet Gait in Neurodegenerative Disease Database. CLPR tracks designed perturbations synthetically but does not separate diagnostic groups in real data (H = 3.262, p = 0.353), a null result robust to representation, covariates and outlier removal. A surrogate-normalized variant that appeared significant was traced to outlier strides. All results are re-executable from the included code; raw PhysioNet data are not redistributed.