  In legged locomotion the projection of the robot Center of Mass (CoM) being
inside the convex hull of the contact points is a commonly accepted sufficient
condition to achieve static balancing. However, some of these configurations
cannot be realized because the joint torques required to sustain them would be
above their limits (actuation limits). In this manuscript we rule out such
configurations and define the Feasible Region, a revisited support region that
guarantees both global static stability in the sense of tipover and slippage
avoidance and of existence of a set of joint-torques that are able to sustain
the robot body weight. We show that the feasible region can be employed for the
selection of feasible footholds and CoM trajectories to achieve static
locomotion on rough terrains, also in presence of load intensive tasks. Key
results of our approach include the efficiency in the computation of the
feasible region thanks to an Iterative Projection algorithm. This allowed us to
carry out successful experiments on the HyQ robot, that was able to negotiate
obstacles of moderate dimensions while carrying an extra 10 kg payload.
