An article of footwear comprising: an upper and a sole; the sole comprising an outer member having an outer surface exposed to the ground, the outer member also having an inner surface opposite the outer surface, the inner surface disposed closer to a wearer's foot than the outer surface; the outer member including at least a first flex groove formed as an elongate recess, the elongate recess causing both the inner surface and the outer surface of the outer member to curve towards the wearer's foot; the first flex groove defining a first flex groove region disposed proximate the first flex groove, the first flex groove also separating a first forefoot region from a second forefoot region; the sole further comprising a reinforcing member attached to the outer member, the reinforcing member being disposed closer to the wearer's foot than the outer member, and the reinforcing member being relatively more rigid than the outer member; the reinforcing member having a first portion disposed in the first forefoot region, the reinforcing member also having a second portion disposed in the second forefoot region, and the reinforcing member having a first bridge portion disposed in the first flex groove region and joining the first portion and the second portion together; wherein the lateral width of the first bridge portion is less than the lateral width of the first portion, and wherein the lateral width of the first bridge portion is less than the lateral width of the second portion, wherein the first bridge portion matches and conforms to the curve towards the wearer's foot of the first flex groove of the outer member. an upper and a sole; the sole comprising an outer member having an outer surface exposed to the ground, the outer member also having an inner surface opposite the outer surface, the inner surface disposed closer to a wearer's foot than the outer surface; the outer member including at least a first flex groove formed as an elongate recess, the elongate recess causing both the inner surface and the outer surface of the outer member to curve towards the wearer's foot; the first flex groove defining a first flex groove region disposed proximate the first flex groove, the first flex groove also separating a first forefoot region from a second forefoot region; the sole further comprising a reinforcing member attached to the outer member, the reinforcing member being disposed closer to the wearer's foot than the outer member, and the reinforcing member being relatively more rigid than the outer member; the reinforcing member having a first portion disposed in the first forefoot region, the reinforcing member also having a second portion disposed in the second forefoot region, and the reinforcing member having a first bridge portion disposed in the first flex groove region and joining the first portion and the second portion together; wherein the lateral width of the first bridge portion is less than the lateral width of the first portion, and wherein the lateral width of the first bridge portion is less than the lateral width of the second portion, wherein the first bridge portion matches and conforms to the curve towards the wearer's foot of the first flex groove of the outer member.