In the world of robotics, for many years, the study of the human-machine relationship has tried to build models based on human anatomy and on the movements that a normal man naturally performs. By imagining this, biped models that referred to human walking or running have been conceived and designed. The purpose of this thesis focuses on the analysis, study and simulation of human walking gait and running gait using as a basis a model of a bipedal robot. Some modifications have been made on it because of a different vision of how the joints positioned along the lower limbs perform their own work.