Michael J. Fox saved from dangerous stunt in Back to the Future by crew member

Michael J. Fox was saved from performing a dicey stunt in Back to the Future after a heated confrontation between director Robert Zemeckis and the first assistant director.

Zemeckis, 73, wanted the front of a car to push the then-23-year-old lead actor on a skateboard to nail a "certain angle", but assistant director David McGiffert put his foot down and rejected Zemeckis' plan because if Fox fell under the car, the star would be seriously hurt.

In his new memoir Future Boy - which tells the making of the 1985 time travel comedy blockbuster - Fox, 64, paid regard to his stunt-double Charlie Croughwell.

Fox - who played Marty McFly in the Back to the Future trilogy - wrote: "Without Charlie, there would be no Back to the Future as we know it.

"I later discovered that Charlie's first stunt was a point of contention between Bob Zemeckis and the 1st AD."

McGiffert recalled in a chat with Fox: "'I don't usually do this, but I had to put my foot down with Bob.

"'He wanted you to be on the skateboard in front of the car, which would be pushing you.

"'He had a certain angle in mind that only worked if you were the one doing the bit, so he said, 'Yeah, I want Michael to do it.'

"'I shook my head. 'Bob, he can't do that.'"

Despite Zemeckis wanting to ensure production on Back to the Future went perfectly, McGiffert continued to reject the director's plan.

He said: "'You can't have your lead actor in that position. I know it's an off chance, but if he falls under the car, it's over in a heartbeat.'"

Fox then recalled Zemeckis escalated the conflict, but he eventually gave in to McGiffert.

Fox said: "Bob really wanted his shot. He insisted again that I do the stunt, and that's when David, in a rare moment of defiance, said, 'OK, if you do that, I'm going to have to put a note on the slate that says 'First AD protests.'

"And that's when Bob relented."

Despite not being able to perform that stunt, Fox did reveal he did "much of my own skateboard work", including "hooking onto a few moving cars as they drove through Courthouse Square".

Fox added: "But Charlie handled the crazy stunts. It was Charlie, not me, who sailed through the air the entire length of Biff's [Thomas F. Wilson] open convertible and reunited with the skateboard as it glided out the other end."