De-identified data and analysis code for: Lower-Body Lean Mass, Not Surface-EMG Amplitude, Tracks Jump Concentric Impulse Change in Baseball Athletes: A Longitudinal Cohort Study

This deposit accompanies the preprint: Crider B., Bloebaum A. "Why Ratio Normalization Fails to Partition Structural and EMG-Amplitude Contributions to Jump Force Change." Driveline Baseball, 2026. It contains the de-identified trial-level summary data and the analysis code required to reproduce every inferential model, the ratio-coupling permutation simulation, the reliability table, the asymmetry-correlation family with FDR correction, and the figures and tables reported in the manuscript.