A built-in or added-on extension is situated upon a side of a shoe so as to minimize or prevent injury caused by inversion of a foot/ankle during athletic or other activities. The extension protrudes laterally out from the side of the shoe and has a substantial horizontal component, with an outer surface portion(s) adapted in shape, size, and/or placement so that said portion(s) will impact the floor/ground upon inversion of the foot/ankle but that none of the extension impacts, rubs, slides, or otherwise contacts the ground/floor during normal activities of the wearer. Said impact/contact only occurs when there is significant ankle/foot inversion, that is, enough to potentially cause a mild lateral ankle sprain. The preferred extension cushions and/or stops inversion at an angle of inversion and/or at a time during the inversion wherein the wearer may recover and straighten his foot/ankle before serious injury to the ankle.