Abstract: An seat cushion is adapted to selectively conform to a user's anatomy with a seat portion having at least one inflatable interior seat compartment with a resiliently compressible foam element disposed therein. The compartment also has an openable and closable seat valve for selectively communicating the seat compartment with the ambient atmosphere. The foam is expanded and compressed within the seat compartment in relation to selective application of a compression force acting on the seat portion when the seat valve is opened to selectively draw inflating air into and exhaust inflating air from the seat compartment.