A backward tucked somersault from the standing position is analyzed in this study. The used computations were based on a three-dimensional model of the human body defined in natural coordinates. The net torques and internal reactions occurring at the ankle, knee, hip, upper trunk-neck and neck-head joints were obtained by inverse dynamics. The achieved results confirmed the significant loads at the joints at the beginning of the landing phase and revealed the way the analyzed stunt was controlled. It was also shown that the natural coordinates provide a useful environment for modeling spatial biomechanical structures.