You would want to duplicate the image (isolated from the background) and run the motion blur filter (adjusting the angle to the direction you want). Then create a layer mask to eliminate the blur that appeared in front of your figure. You could erase it too (which is a lot easier but not adjustable...)

If you want to get fancy and make it look like the motion you'd see in Flash (the comic book not the program!) then open blured layer in the Liquify filter window and play around there.

The best way is to experiment.

:)
retrocity