Sole structures, foot support systems, articles of footwear, and/or other foot-receiving devices include: (a) a first footwear component having a ground-facing surface, wherein a forefoot portion of the ground-facing surface includes arched medial and lateral surfaces and (b) a second footwear component having an upper-facing surface, wherein a forefoot portion of the upper-facing surface includes arched medial and lateral surfaces that face (and optionally contact) the respective arched medial and lateral surfaces of the first footwear component. The first and second footwear components are movably engaged together such that: (a) the arched medial surface of the first footwear component moves with respect to and along the arched medial surface of the second footwear component and (b) the arched lateral surface of the first footwear component moves with respect to and along the arched lateral surface of the second footwear component.