This study leverages 3D human modeling and gait analysis using multibody dynamics to enhance the understanding of human locomotion. By integrating detailed biomechanical models with computational methods, it provides a comprehensive analysis of gait patterns, overcoming traditional limitations. The model segments the body into various rigid parts, connected by spherical joints, to simulate realistic movements. Accurate foot-ground contact dynamics are modeled using a Hertzian-based normal contact force with dissipated damping and a modified Coulomb friction model, with a CT scan of a complete foot improving precision. This advanced approach significantly enhances the fidelity of human movement simulation and offers potential for clinical applications in diagnosing and treating gait disorders.