I remember a few years back when engineers were saying that leg-locomotion on robots is entirely too difficult to be fesasable, too expensive to develop and too complicated to balance.  Of course, as always happens, an intrepid group of engineers have found a way through that wall and produced rather impressive results.   The video below is a sort of field test of a prototype called ‘Big Dog’ by Boston Dynamics, research funded (surprise surprise)  by DARPA.  Military applications for something like this are vesatile, and as you can see with the video, the thing is pretty good at staying on its feet.

Now if they could only figure out how to add this to Asimo…