Flexible arch support for footwear

An arch support for insertion into footwear, the arch support comprising:

• a frame defining a perimeter of the arch support, a first side of the frame configured to underlie a medial side of a wearer's foot and a second side of the frame configured to underlie a lateral side of the wearer's foot, wherein the frame is discrete and further configured for coupling to an insole;
• and a plurality of ribs embodied within the frame and extending from the first side of the frame to the second side of the frame, wherein a first set of the ribs is raised relative to a second set of the ribs, and wherein the first set of ribs are positioned entirely between the second set of ribs to form an alternating array of opposing independent leaf spring ribs configured to move toward each other in response to application of force by a wearer's foot, wherein the frame embodying the plurality of ribs is configured for placement directly beneath the arch of the wearer's foot, and wherein the longitudinal extent of the frame is bound between the talus-navicular joint and the medial cuneiform-first metatarsal joint.