Almost all walking robots are composed of two or more multi-degrees-of-freedom (DOFs) legs which give them a good ability to traverse obstacles. Nevertheless, their speed and efficiency when traversing rough terrains is, in most cases, arguably limited. Additionally, they have the disadvantage of a generally lower reliability. The design of robust and efficient 1-DOF leg is, on the other hand, a complex process. In this paper, a method to analyze and optimize 1-DOF robotic legs is proposed. The results of a virtual simulation are used in combination with some performance indices to optimize the geometric parameters of 1-DOF legs. Finally, the results of the simulation and the actual walking performance of a prototype using four legs with the computed optimal parameters are presented and compared with the simulator results. The validation of the simulation model and the optimization method proposed in this paper represents the main contribution of this work.