A
loser lunge is an action associated with 'hacky
sack' or 'footbag'. This action is expressed when the hacky sack is in an inconvenient place, usually unreachable by the original kicker.
Therefore, someone else, or the original kicker will try to extend his or her leg as far as possible, trying to "lunge" for the hacky sack to keep the play alive.
The saying is derived from how the person who lunged for the hacky sack is usually determined as the
loser. It is customary, and acceptable that the other players insult the
loser lunger.