Reciprocating motion occurs when the file is progressed in a variable order in the direction of rotation with the movement of the endomotor. The file used in the treatment first scans an obtuse angle counterclockwise and scans an acute angle clockwise before repeating this process. In this way, it turns into a repeated oscillation. The whole process is called reciprocal movement.
The greatest advantage provided by this process is that the compression of the file within the narrowing canal is prevented by relaxation with the movement in opposite direction.