Despite being on a panel to discuss his foundation's contributions to Parkinson's research, actor Michael J. Fox reluctantly fielded a question Sunday about how the hoverboard sequence in the film Back To The Future Part II was filmed. 'Um, well, we mostly used a system of pulleys to move us forward and back,' said Fox, who since being diagnosed with Parkinson's has worked tirelessly to find a cure for the degenerative disease. 'Anyway, much like the hoverboard got me where I wanted to go in Back To The Future, let's get back to what I was saying about translational research, which will get all of us where we want to go to in order to beat Parkinson's.' Fox was later asked if his new book Always Looking Up: The Adventures Of An Incurable Optimist had any further information about Griff's jet-propelled 'Pit Bull' hoverboard. 