This disclosure describes a patient support (10, 900) having an air permeable layer (20, 91, 91', 920), a plurality of inflatable bladders (50, 60, 62, 64, 66, 72, 74, 74a, 74b, 76, 78, 80, 84, 86, 90, 140, 142, 960, 962, 963, 964, 965, 966, 974, 974a, 974b, 980, 984, 990, 992, 994, 996), a pressure sensing assembly (68, 70, 328, 968, 970, 1048), and a controller (42,58,958,1542). In one embodiment, a combination of transverse bladders (960, 962, 963) and vertically oriented can-shaped bladders (964, 965) is provided. In one embodiment, one or more angle sensors (502, 1502, 1262) are provided in articulatable sections (32, 34, 932, 934) of the patient support (10, 900).
