Abstract: Impact-attenuating elements for footwear or the like may include (a) a first impact-attenuating material (e.g., foam) in a first region; and (b) a second impact-attenuating material in a second region (e.g., foam of a higher density). At least one characteristic of the impact-attenuating characteristics (e.g., support) provided by the impact-attenuating element may be controlled by changing a position or orientation of at least a portion of the impact-attenuating element in the footwear. For example, the “firmness” of the support provided by the impact-attenuating element may be changed by rotating or flipping the impact-attenuating element so that foam of a different density is provided at different areas of the foot.

Abstract: An article of footwear includes a flexible cover shaped to envelope at least a portion of a wearer's foot. The cover has a sole region with inner and outer surfaces, the inner surface positioned to face the sole of the wearer's foot and the outer surface positioned to face in an opposite direction. The cover also has a plurality of apertures formed in the sole region. The article further includes a removable outsole nested within the cover. The outsole has an upper surface positioned to face the sole of the wearer's foot, a lower surface facing the inner surface of the cover sole region, and a plurality of lugs on the lower surface which protrude into the plurality of apertures.