I don't know what is being taught or how it could be explained in a book. This is as we are taught regardless of who goes backward. Waltz. Lower at the end of three with an and count. On that count the, man in this case, will release the the LF and extent it a few inches. Then extend it to its full stride. The lady at the end of three ,her feet are parallel. Done any other way will cause the person going back to be pushed . That's if all four feet are parallel at the end of three.
Does that make sense to anyone. If not have a look at your instruction tapes. It's there to see' Happy Landing.