MABEL Bipedal robot "hops" when it runs

From IEEE Automation: http://spectrum.ieee.org/automaton/robotics/humanoids/mabel-bipedal-robot-is-now-fast-enough-to-catch-you

MABEL, a robot from the University of Michigan, has multiple features that copy humans impressively:

"...MABEL has a torso that's substantially heavier than its legs, just like a human, and it's also got a system of springs that act like tendons. This gives MABEL a very human-like, bouncing gait, and the robot spends 40% of its time running in a "flight phase" with both feet off the ground, similar to humans..."

It still needs to be tethered to a pole so that it doesn't fall over, but it moves forward pretty interestingly. The video below shows a lot. It looks like it handles and maneuvering its weight very well when it runs, at least for a robot.