back and forth backward and forward to and fro
back_and_forth%4:02:00:: backward_and_forward%4:02:00:: to_and_fro%4:02:00::
moving from one place to another and back again
he traveled back and forth between Los Angeles and New York the treetops whipped to and fro in a frightening manner the old man just sat on the porch and rocked back and forth all day