He calls his robot Athlete. Each leg has seven sets of artificial muscles. The sets, each with one to six pneumatic actuators, correspond to muscles in the human body -- gluteus maximus, adductor, hamstring, and so forth [see diagram below].
To simplify things a bit, the robot uses prosthetic blades, of the type that double amputees use to run.
And to add a human touch, Niiyama makes the robot wear a pair of black shorts.
The first such robot, built in 2007, couldn't take one step without falling. Athlete, on the other hand, can sprint three to five steps before falling over, as you'll see in an unintentionally humorous video. Link -via DiscoBlog