Abstract: A bed arrangement (10) has an articulated mattress support (30), a support frame (40) for the articulated mattress support, and a power assembly (50) for raising and lowering flexible sections (30b, 30c, 30d) of the articulated mattress support. The support frame (40) is adjustably mounted in a stationary outer frame (20) and has a size smaller than the articulated mattress support (30). The power assembly (50) is mounted on the support frame (40).