Patented recently is a body conformance system which includes at least one liquid-permeable, flexible containment layer, and an operative quantity of substantially free-flowing particulate material constrained by the flexible containment layer. In a particular aspect, the substantially free-flowing particulate material can exhibit a selected avalanche-time between avalanches. In another aspect, the particulate material can exhibit a selected, minimum retention capacity. In a further aspect, the system can exhibit a distinctive gap-protrusion area. In yet another aspect, the containment layer can include a material that has a relatively high permeability to liquid, but a relatively high resistance to a passage of the particulate material.