A 1/5 human scale "humanoid" biomorhic platform has been developed at Iguana. This device uses cable driven actuators configured in an agonist/antagonist configuration. The cables are routed through the center of the axis of rotation of each joint.
Note, that bi-articular muscles can be modeled with this system. For example, if the cable passing through the knee is eccentric with the axis of knee rotation, and the attachment point is on the foot and is not at the axis of rotation, then torques will be produced at both the knee and ankle.
Researchers use Marilyn to investigate principles of the neurocontrol of movement. Marilyn is sold in limited quantities to the research community.