An article of footwear, comprising: a sole member having an outwardly facing surface and an inwardly facing surface disposed opposite of the outwardly facing surface , wherein the outwardly facing surface is disposed further from a foot than the inwardly facing surface when the article of footwear is worn; the sole member having a vertical direction that extends between the outwardly facing surface and the inwardly facing surface ; a protruding member assembly including a plurality of protruding members (152; 1102; 1104; 1131; 1132; 1133) connected together by a plurality of connecting portions (154; 1120); the plurality of protruding members (152; 1102; 1104; 1131; 1132; 1133) further including proximal end portions that provide an inner surface (157; 1045) for the protruding member assembly and the plurality of protruding members including distal end portions (164; 1103; 1105) that provide an outer surface for the protruding member assembly ; the sole member including a plurality of holes to receive the plurality of protruding members (152; 1102; 1104; 1131; 1132; 1133) such that the distal end portions (164; 1103; 1105) of the plurality of protruding members (152; 1102; 1104; 1131; 1132; 1133) extend away from the outwardly facing surface ; wherein the plurality of protruding members (152; 1102; 1104; 1131; 1132; 1133) can move relative to the sole member in the vertical direction; wherein the geometry of the inner surface (157; 1045) of the protruding member assembly changes as the plurality of protruding members (152; 1102; 1104; 1131; 1132; 1133) move in response to forces applied to the outer surface of protruding member assembly , and wherein the connecting portions are elastic and characterised in that the connecting portions stretch as forces are applied to the outer surface of the protruding member assembly . a sole member having an outwardly facing surface and an inwardly facing surface disposed opposite of the outwardly facing surface , wherein the outwardly facing surface is disposed further from a foot than the inwardly facing surface when the article of footwear is worn; the sole member having a vertical direction that extends between the outwardly facing surface and the inwardly facing surface ; a protruding member assembly including a plurality of protruding members (152; 1102; 1104; 1131; 1132; 1133) connected together by a plurality of connecting portions (154; 1120); the plurality of protruding members (152; 1102; 1104; 1131; 1132; 1133) further including proximal end portions that provide an inner surface (157; 1045) for the protruding member assembly and the plurality of protruding members including distal end portions (164; 1103; 1105) that provide an outer surface for the protruding member assembly ; the sole member including a plurality of holes to receive the plurality of protruding members (152; 1102; 1104; 1131; 1132; 1133) such that the distal end portions (164; 1103; 1105) of the plurality of protruding members (152; 1102; 1104; 1131; 1132; 1133) extend away from the outwardly facing surface ; wherein the plurality of protruding members (152; 1102; 1104; 1131; 1132; 1133) can move relative to the sole member in the vertical direction; wherein the geometry of the inner surface (157; 1045) of the protruding member assembly changes as the plurality of protruding members (152; 1102; 1104; 1131; 1132; 1133) move in response to forces applied to the outer surface of protruding member assembly , and wherein the connecting portions are elastic and characterised in that the connecting portions stretch as forces are applied to the outer surface of the protruding member assembly . <EOS>