Sub animations

Is it possible to have one animation that is part of another larger animation which will then be controlled through an animation controller? The reason that I ask this is that I am making a walking animation and would like a seperate animation from the feet, than that of the rest of the body. This would allow me to more easily modify the animation of the feet and would also allow me to repeat the animation used for one foot on the second, just with a delay. How may i go about doing this?

Yes I know i can have an animated foot sub object, but how would I then control both the feet and the rest of the body in the animation controller? Is there a better way to accomplish what I want?