The article is devoted to the description of the validation of the dynamic model of an angular manipulator with three degrees of freedom of movement based on the chosen course of excitation of pneumatic artificial muscles from the manufacturer FESTO. The dynamic model consists of the dynamics of the manipulator arm and the dynamics of the pneumatic part of the experimental system. The motion equations were derived based on Lagrangian formalism and the dynamic of muscle contraction can be described using Newton's second law. The overall model of the system was implemented in the Matlab Simulink environment. The outputs of the validations were compared with the measured data from the real system. The observed parameter was the angle of rotation of the joint. Two statistical indicators were used to compare the simulation outputs (model) with the system outputs (measurements), namely NRMSE (Normal Root Mean Square Error) and MAE (Mean Absolute Error).