Michael J. Fox was at an event themed around Back to the Future when he fell while onstage. 61-year-old Fox has been battling Parkinson's since the '90s and recently admitted that his condition has been worsening and had become much "harder." The Pennsylvania Convention Center hosted a fan expo for Back to the Future lovers, with Fox in attendance, celebrating his part as Marty McFly in the role that cemented his place in pop culture history. During the Q&A session in which Fox fell, he was joined by Christopher Lloyd and Tom Wilson. Michael J. Fox fell while onstage at a 'Back to the Future' fan expo Michael J. Fox tripped while heading onstage at a Back to the Future fan expo / YouTube screenshot Fox's onstage scare came on Sunday during a Q&A session with his Back to the Future peers. He had been walking onto the stage when Fox tripped. Fortunately, Page Six reports, Fox landed on a couch. This kept him safe enough that he actually continued the Q&A session with Wilson and Lloyd. RELATED: Michael J. Fox Went From A Promising Career To Promising Hope With Parkinson’s Research Fox admitted that he's suffered a number of injuries since his Parkinson's diagnosis, which started back when he was just 29. The neurological disorder causes shakiness and stiffness, damaging a person's mobility control over time. "I broke this shoulder — had it replaced," shared Fox in an interview with Variety. "I broke this elbow. I broke this hand. I had an infection that almost cost me this finger. I broke my face. I broke this humerus." Fox admitted that his Parkinson's has been getting worse Even before tripping onstage, Fox has admitted he's suffered some serious injuries because of Parkinson's / Theresa Shirriff/AdMedia Since his diagnosis and after going public, Fox has become the face of the battle against Parkinson's. His organization, The Michael J. Fox Foundation, has provided millions in research funding. However, Fox has revealed that his condition has deteriorated and will continue to do so. "Every day, it’s tougher," admitted Fox, adding, "But that’s the way it is. I’m not gonna be 80." It's a notion he's frequently confronted with, as Fox further revealed that his situation has him often "thinking about the mortality of it." BACK TO THE FUTURE PART II, Michael J. Fox, Christopher Lloyd, 1989. (c)Universal/courtesy Everett Collection But Fox is not alone - though even help comes with significant drawbacks. "I have aides around me quite a bit of the time in case I fall, and that lack of privacy is hard to deal with," he explained. "I lost family members, I lost my dog, I lost freedom, I lost health. I hesitate to use the term 'depression,' because I'm not qualified to diagnose myself, but all the signs were there." To counterbalance this, "I just enjoy the little math problems of existence. I love waking up and figuring that stuff out and at the same time being with my family."