The purpose of this master thesis is to carry on a study on the effects induced by the structural elasticity in robotics systems. New challenges are oriented towards bioinspired, safe and energy efficient solutions. For instance nowadays advanced robots are not confined anymore to factories and manufacturing tasks, they have been designed to help humans in a vast variety of daily tasks. The introduction of elastic components could be a solution, if robots are conceived as structurally flexible they become lighter, this means that they need less energy to perform the same tasks with respect to their rigid counterparts. In addiction elastic components can store energy and release it in a later time, this brings to an increasing of the efficiency of the whole system.