Hey,
I searched this subjects years ago.
The best ressources i could find :
Naturalmotion’s system, used in gta, star wars the force unleashed, etc.
And this is recent, i dont understand why they dont make this as a game middleware, seems like researchers do not really know what to do with their work lol, once the thesis is published, it is forgotten :
Flexible Muscle-Based Locomotion for Bipedal Creatures
This is 2 years old, but evolved neural networks for motion is a really old idea.
Most people are trying hard to take the problem of biped locomotion from the opposite side, using inverse kinematics to place foots or hands while not solving the real problem at all.
Just see the presentation of paragon a couple of weeks ago, how they managed foot placement, and root motion.
Balancing is the main challenge. It seems neural networks are doing a great job at it, in reality, this is how nature does it.
Some researcher are working hard and bringing a lot of innovations, but the industry isnt giving a try.