Some embodiments are directed to an airbag assembly for protecting a vehicle occupant having a torso and a pelvis disposed in a vehicle seat. The airbag assembly can include a first inflatable chamber disposed in the vehicle seat and configured to expand outward from the vehicle seat to indirectly support the torso of the occupant. The airbag assembly can also include a second inflatable chamber disposed in the vehicle seat below the first inflatable chamber and configured to expand outward from the vehicle seat below the first inflatable chamber. The airbag assembly can further include a sheet connecting the first inflatable chamber to the second inflatable chamber, the sheet being configured to engage the torso of the occupant when the occupant is disposed in the vehicle seat.