Pronation control customising system for an article of footwear, the system comprising: a sole comprising a midsole of a continuous elastomeric first material having a first durometer, the midsole having an upper, foot-facing surface and a lower, ground-facing surface, a plurality of vertical cavities in a first region of the midsole, each vertical cavity extending along a vertical axis substantially orthogonally to the upper surface, between the lower and the upper surfaces of the midsole, and a plurality of support adjustment elements, for each being substantially wholly inserted into one of the vertical cavities so as to adjust a vertical support hardness of the sole at the location of said each vertical cavity; wherein each vertical cavity comprises a insertion opening in the upper surface and/or in the lower surface for receiving one of the support adjustment elements, and wherein the plurality of support adjustment elements comprises a first support adjustment element having a second durometer and a second support adjustment element having a third durometer, different from the second durometer, wherein at least one of the second and third durometers is greater than the first durometer, wherein the cavities and support adjustment elements are each configured such that the net vertical hardness of the sole at the location of each cavity is determined in a great majority by the hardness of the particular insert in the cavity, and wherein the cavities and support adjustment elements are arranged for pronation control such that a first plurality of the vertical cavities is arranged in a first pronation control region of the sole, and a second plurality of the vertical cavities is arranged in a second pronation control region of the sole, the first and second pronation control regions (21, 22) being on medial and lateral sides, respectively, of the ideal gait line of the sole. a sole comprising a midsole of a continuous elastomeric first material having a first durometer, the midsole having an upper, foot-facing surface and a lower, ground-facing surface, a plurality of vertical cavities in a first region of the midsole, each vertical cavity extending along a vertical axis substantially orthogonally to the upper surface, between the lower and the upper surfaces of the midsole, and a plurality of support adjustment elements, for each being substantially wholly inserted into one of the vertical cavities so as to adjust a vertical support hardness of the sole at the location of said each vertical cavity; wherein each vertical cavity comprises a insertion opening in the upper surface and/or in the lower surface for receiving one of the support adjustment elements, and wherein the plurality of support adjustment elements comprises a first support adjustment element having a second durometer and a second support adjustment element having a third durometer, different from the second durometer, wherein at least one of the second and third durometers is greater than the first durometer, wherein the cavities and support adjustment elements are each configured such that the net vertical hardness of the sole at the location of each cavity is determined in a great majority by the hardness of the particular insert in the cavity, and wherein the cavities and support adjustment elements are arranged for pronation control such that a first plurality of the vertical cavities is arranged in a first pronation control region of the sole, and a second plurality of the vertical cavities is arranged in a second pronation control region of the sole, the first and second pronation control regions (21, 22) being on medial and lateral sides, respectively, of the ideal gait line of the sole.