Michael J. Fox and Charlie Croughwell (right).
Charlie Croughwell is a professional stuntman who played the role of Marty McFly in those parts of the film that required stunt work, and who has served as the stunt double for Michael J. Fox since Croughwell's film debut in Back to the Future. Croughwell bears some resemblance to Fox, and is actually slightly shorter. In the scene where Marty is chased through Courthouse Square by Biff's gang, Fox did much of the skateboarding on level ground, while Croughwell did the leaps and falls. Croughwell's most spectacular stunt in the film was the scene where Marty walks up the hood, through the interior, and back over the trunk of a speeding convertible. With skillful editing, the intercut of Fox's and Croughwell's footage made it appear as if all the work had been done by one person.
In Part III, Charlie Croughwell, R.L. Tolbert, and Jennifer Watson worked together as Marty, Doc and Clara, respectively, for the train hijacking in 1885.
A close friend of Fox, Croughwell served as Fox's stunt double in subsequent films. In addition to work on Back to the Future Part II and Back to the Future Part III (which featured chases through Courthouse Square in 2015 and 1885, respectively), Croughwell has been in Light of Day, The Secret of My Succe$s, Bright Lights, Big City, The Hard Way, and other of Fox's films.