In this Chapter, several demonstrative application examples are presented, that range from simple systems such as the classic bouncing ball and slider-crank mechanism with external impact on a free slider block, internal impacts of mechanisms with revolute joint clearances, to more complex systems, such as the human knee joint contact and the foot-ground interaction models. In order to keep the analysis simple, only few contact force models are utilized, namely those that provide better response in terms of accuracy and efficiency.