In many simple machines, if the load force "Fout" on the machine is high enough in relation to the input force "Fin", the machine will move backwards, with the load force doing work on the input force. So these machines can be used in either direction, with the driving force applied to either input point. For example, if the load force on a lever is high enough, the lever will move backwards, moving the input arm backwards against the input force. These are called ""reversible"", ""non-locking"" or ""overhauling"" machines, and the backward motion is called ""overhauling"".