The worst record for a playoff team that played a full, 16 game regular season is 7-9, belonging to the 2010 Seattle Seahawks. There have also been nine 8-8 playoff teams as of the end of 2010: 1....
The San Diego Chargers started there season 4-8 and they made it to the playoffs and won a playoff game
2008-2009 san Diego chargers
Bruins
8-4 by the 1947 Philadelphia Eagles, 1951 Los Angeles Rams, 1952 Cleveland Browns, 1957 Detroit Lions, and 1960 Green Bay Packers.