Most sows in the European pig industry are kept in confinement, and are restricted in the amount of locomotory exercise they can perform. Any difficulty in carrying out the movements necessary for standing up and lying down, due to a lack of muscular and cardiovascular fitness, can indicate poor welfare for the sow. Also, because a large proportion of piglet mortality is attributable to over-lying by the sow when she lies down or stands up clumsily, there are welfare implications for her litter. The objectives of these studies were to investigate the time taken for sows to lie down in different dry sow housing systems, and to determine any relationships between the time taken and body dimensions of the sow.