A device configured to surround a portion of a foot-receiving cavity at a heel region of an article of footwear, the device comprising: a control bar having a center segment, a first side arm extending from the center segment, and a second side arm spaced from the first side arm and extending from the center segment; a continuous base supporting the control bar and connected to both of the first side arm and the second side arm; wherein the control bar is biased to an unstressed position with the center segment a first distance from the base, the control bar elastically deforms under an applied force to a loaded position with the center segment a second distance from the base less than the first distance, and the device stores potential energy that returns the control bar to the unstressed position upon removal of the applied load; wherein the base is connected to the first side arm at a first joint, and the base is connected to the second side arm at a second joint; wherein the base has a center segment, a first base arm, and a second base arm all disposed in a common plane; the first base arm is spaced apart from the second base arm and both extend from the center segment of the base; the first base arm and the first side arm are connected at the first joint; the second base arm and the second side arm are connected at the second joint; the first side arm and the second side arm extend at a first acute angle to the common plane of the base when the control bar is in the unstressed position; the first side arm and the second side arm extend at a second acute angle to the common plane of the base when the control bar is in the loaded position; and the second acute angle is less than the first acute angle; the first side arm and the second side arm each have at least one slot extending therethrough, wherein the control bar includes a series of slats each extending along the first side arm, the center segment, and the second side arm, and wherein the at least one slot includes a series of slots, each extending along the first side arm, the center segment, and the second side arm and disposed between respective adjacent ones of the slats. a control bar having a center segment, a first side arm extending from the center segment, and a second side arm spaced from the first side arm and extending from the center segment; a continuous base supporting the control bar and connected to both of the first side arm and the second side arm; wherein the control bar is biased to an unstressed position with the center segment a first distance from the base, the control bar elastically deforms under an applied force to a loaded position with the center segment a second distance from the base less than the first distance, and the device stores potential energy that returns the control bar to the unstressed position upon removal of the applied load; wherein the base is connected to the first side arm at a first joint, and the base is connected to the second side arm at a second joint; wherein the base has a center segment, a first base arm, and a second base arm all disposed in a common plane; the first base arm is spaced apart from the second base arm and both extend from the center segment of the base; the first base arm and the first side arm are connected at the first joint; the second base arm and the second side arm are connected at the second joint; the first side arm and the second side arm extend at a first acute angle to the common plane of the base when the control bar is in the unstressed position; the first side arm and the second side arm extend at a second acute angle to the common plane of the base when the control bar is in the loaded position; and the second acute angle is less than the first acute angle; the first side arm and the second side arm each have at least one slot extending therethrough, wherein the control bar includes a series of slats each extending along the first side arm, the center segment, and the second side arm, and wherein the at least one slot includes a series of slots, each extending along the first side arm, the center segment, and the second side arm and disposed between respective adjacent ones of the slats.