Hybrid Resistance Acceleration Profile

Reference implementation of the equation-of-motion model, sensitivity analysis, and Hill-type force-velocity extension described in the manuscript "Same Load, Different Physics: Towards Acceleration-Based Training with Hybrid Resistance" (Dolci & Dolci), submitted as a preprint to SportRxiv. The script reproduces, using only the Python standard library: - A numerical convergence check for the semi-implicit Euler integration scheme- Baseline kinematics (initial acceleration, ROM completion time, deceleration onset) for four resistance configurations: free weight only, band, pneumatic, and full hybrid- The full sensitivity analysis (±20% one-at-a-time perturbation of seven model parameters)- The Hill-type force-velocity extension across apparent Vmax = 4–20 m/s- The composition example from "Expressing Hybrid Load in Practice" (fixed total resistance at end of range of motion, varying free-weight/band split) All printed values match the corresponding figures reported in the manuscript exactly. Requires Python 3, standard library only, no external dependencies. Run with: python hybrid_resistance_model.py