An article of footwear, comprising: an upper configured to receive a wearer's foot when the footwear is worn by the wearer; and a sole assembly coupled to the upper; wherein the sole assembly includes a midsole, an outsole, and a heel assembly; wherein the outsole has an outer surface configured to contact a ground surface on which the wearer is striding and an inner surface adjacent to the midsole; wherein the heel assembly includes an anterior surface, a posterior surface, a lateral surface, and a medial surface; and wherein the heel assembly further includes an upper heel layer, a lower heel layer, and a heel dampening system; wherein the upper heel layer is located generally above the heel dampening system and extends from the medial surface of the heel assembly to the lateral surface of the heel assembly, and wherein the upper heel layer includes a cushion aperture that extends through the upper heel layer from an upper surface of the upper heel layer to a lower surface of the upper heel layer; wherein the lower heel layer is located generally below the heel dampening system and extends from the medial surface of the heel assembly to the lateral surface of the heel assembly; and wherein the heel dampening system includes a heel dampening layer that extends from the medial surface of the heel assembly to the lateral surface of the heel assembly and extends from the posterior surface of the heel assembly toward the anterior surface of the heel assembly, and that is configured to at least partially absorb an impact force when the heel assembly impacts the ground surface; and wherein the heel dampening system further includes a cushioning projection that extends from the heel dampening layer and that extends at least partially through the cushion aperture in the upper heel layer. a sole assembly coupled to the upper; wherein the sole assembly includes a midsole, an outsole, and a heel assembly; wherein the outsole has an outer surface configured to contact a ground surface on which the wearer is striding and an inner surface adjacent to the midsole; wherein the heel assembly includes an anterior surface, a posterior surface, a lateral surface, and a medial surface; and wherein the heel assembly further includes an upper heel layer, a lower heel layer, and a heel dampening system; wherein the upper heel layer is located generally above the heel dampening system and extends from the medial surface of the heel assembly to the lateral surface of the heel assembly, and wherein the upper heel layer includes a cushion aperture that extends through the upper heel layer from an upper surface of the upper heel layer to a lower surface of the upper heel layer; wherein the lower heel layer is located generally below the heel dampening system and extends from the medial surface of the heel assembly to the lateral surface of the heel assembly; and wherein the heel dampening system includes a heel dampening layer that extends from the medial surface of the heel assembly to the lateral surface of the heel assembly and extends from the posterior surface of the heel assembly toward the anterior surface of the heel assembly, and that is configured to at least partially absorb an impact force when the heel assembly impacts the ground surface; and wherein the heel dampening system further includes a cushioning projection that extends from the heel dampening layer and that extends at least partially through the cushion aperture in the upper heel layer.