@jim said:

These (simple) legs were done by using sub-components and smart placement of the component's axes. By making the upper and lower parts sub-components of the leg, I didn't need to worry about their positions - rotating the parent leg rotates both the upper and lower parts together, no matter what their local position/rotation is.

Then by placing the lower leg's axis at the top of the component (at the knee), I just had to set it's RotY attribute to make the lower part rotate.

PS: Technically, this animation is only a half-stride.

You my friend, are my saviour... i`ve been trying to figure this out for the past three days without any success..
thank you! thank you so much!