Abstract: A support device (10) includes a plurality of interconnected support units (12) arranged in a matrix. Each support unit (12) includes a plurality of support elements (16) configured to deform laterally outwardly when the support unit (12) is subjected to a compressive load in a load direction (54). A pre-compression is induced in the support units (12) by laterally pre-tensioning the support units (12) by means of springs (25) connected to a peripheral frame. Hence, when a support unit (12) is subjected to a compressive load in the load direction (54) it expands laterally which serves to relieve, at least partially, the pre-tension in the support units (12) connected thereto which then extend in the load direction under the influence of the springs (24).