A prosthetic foot device includes an elongated upper forefoot portion, an ankle portion, and a lower footplate. The forefoot portion can extend rearwardly through an upper attachment section, downwardly through an ankle section, forwardly through an arch section, and to a toe section. The ankle portion can attach to the forefoot portion, and can extend rearwardly through an upper attachment section, downwardly through an ankle section, forwardly under the ankle section of the forefoot portion, and rearwardly to a heel section, in a substantial s-shaped profile. The lower footplate is disposed under the ankle and forefoot portions, and can extend through a heel section, an arch section, and to a toe section. The upper forefoot portion, the ankle portion, and the lower footplate are flexible to store energy and resilient to return energy.