[QUESTION] Stretchy Ball Rig Spin Control?

So I recently finished the rigging part of the new Treasure Chest course and I wanted to use my brand new knowledge to make a stretchy ball rig. I got most of the way there but I'm having trouble adding a spin control. Wayne Dixon had a spin control on the ball rig from the Animation Bootcamp course but I couldn't figure out how to make it work with my current rig. I made a short video which hopefully gives you a better idea of what I'm trying to do.

Video: https://www.youtube.com/watch?v=HSlX6GMt5iQ&feature=youtu.be

Thank you very much!