Procedural motion with Urho?

Does anyone have any idea how to do something like this in Urho?

Note that the object smoothly leans into the direction the player is going. I’m assuming there’s a bone or two between the spheres, and that the bone is being manipulated by code somehow. That’s the part that I don’t understand: how does it manipulate the bone, and how so smoothly? Is it some easing curve based on the direction the player is facing? Does it apply to bone rotation only, or is it IK?

This video explains it best: