Modelling and Simulation of a Four Legged Robot Legged animals are capable of rapid movement, are efficient from the point of view of the energy and are able to adapt their gait depending on environmental conditions. Motions like walking, trotting, galloping and jumping, are difficult to evaluate and replicate due to their being consequence of tricky interaction of different system like the musculoskeletal system and the central and peripheral nervous systems, not to mention the in influence of the environment. In this paper we present the implementation, the test, and we study the response of, a four-legged robot with 1 DOF for each leg and with motors placed on the hip.