Michael J. Fox laughs about his Parkinson's disease.

The 'Back to the Future' actor was diagnosed with the crippling condition, which causes his body to spasm inopportunely, aged 30, but more than 20 years later he has learned to live with his illness and prefers to see the lighter side to Parkinson's.

Although his body has deteriorated, Michael - who still enjoys playing golf - joked: ''People say, 'Stay still over the ball.' I'm, like, 'Yeah, screw you.'

''When I start pouring cereal, I don't know what's going to happen. The next thing I know, I'm spraying All-Bran all over the kitchen.''

Despite his good humour, the 51-year-old actor - who has four children, Sam, 23, twins Aquinnah and Schuyler, 18, and 11-year-old Esmé, with his wife of 24 years, Tracy Pollan - admits it is a daily struggle to deal with his condition.

In an interview with the April/May issue of AARP The Magazine, he said: ''It's like your gyroscope is off. I can be shaky. I can be slow. I can wake up with [my feet shuffling involuntarily], and I'll say, 'This is going to be a struggle today.' ''

Michael is set to return to TV with his own sitcom later this year and he revealed that having a positive attitude about his illness has given him the ''freedom to do other things'' and enjoy his life.

He explained: ''There's an idea I came across a few years ago that I love ... My happiness grows in direct proportion [to] my acceptance and in inverse proportion to my expectations. That's the key for me. If I can accept the truth of, 'This is what I'm facing -- not what I can expect, but what I am experiencing now', then I have all this freedom to do other things.''