An insert for use with an article of footwear adapted to engage a foot, the article of footwear having a sole structure and an upper portion connected to the sole structure, the insert comprising: an insert member adapted to be placed in contact with the sole structure of the article of footwear, the insert member comprising a central portion adapted to be engaged by a metatarsal portion of the foot, a first phalange portion extending from a front edge of the central portion and adapted to be engaged by a first phalange of the foot, and a heel portion extending from a rear edge of the central portion and adapted to be engaged by a heel of the foot, wherein the central portion has a length measured from the front edge to the rear edge and a width measured perpendicular to the length, and wherein the heel portion extends from the rear edge of the central portion in an elongated manner and has a width that is narrower than the width of the central portion and a length that is greater than the width of the heel portion; and a sensor system comprising a plurality of force sensors connected to the insert member and a port configured for communication with an electronic device, wherein at least one of the force sensors is positioned on the central portion, at least one of the force sensors is positioned on the first phalange portion, and at least one of the force sensors is positioned on the heel portion, and wherein the port is positioned on the central portion; characterized in that: the first phalange portion extends from the front edge of the central portion in an elongated manner and has a width that is narrower than the width of the central portion and a length that is greater than the width of the first phalange portion, wherein the insert member has a peripheral edge defining a periphery of the insert member; and the peripheral edge comprises a front medial edge extending from a medial side of the central portion to a medial side of the first phalange portion and a front lateral edge extending from a lateral side of the central portion to a lateral side of the first phalange portion, and wherein the front medial edge has an outwardly-curved shape and the front lateral edge has an inwardly-curved shape. an insert member adapted to be placed in contact with the sole structure of the article of footwear, the insert member comprising a central portion adapted to be engaged by a metatarsal portion of the foot, a first phalange portion extending from a front edge of the central portion and adapted to be engaged by a first phalange of the foot, and a heel portion extending from a rear edge of the central portion and adapted to be engaged by a heel of the foot, wherein the central portion has a length measured from the front edge to the rear edge and a width measured perpendicular to the length, and wherein the heel portion extends from the rear edge of the central portion in an elongated manner and has a width that is narrower than the width of the central portion and a length that is greater than the width of the heel portion; and a sensor system comprising a plurality of force sensors connected to the insert member and a port configured for communication with an electronic device, wherein at least one of the force sensors is positioned on the central portion, at least one of the force sensors is positioned on the first phalange portion, and at least one of the force sensors is positioned on the heel portion, and wherein the port is positioned on the central portion; characterized in that: the first phalange portion extends from the front edge of the central portion in an elongated manner and has a width that is narrower than the width of the central portion and a length that is greater than the width of the first phalange portion, wherein the insert member has a peripheral edge defining a periphery of the insert member; and the peripheral edge comprises a front medial edge extending from a medial side of the central portion to a medial side of the first phalange portion and a front lateral edge extending from a lateral side of the central portion to a lateral side of the first phalange portion, and wherein the front medial edge has an outwardly-curved shape and the front lateral edge has an inwardly-curved shape. the first phalange portion extends from the front edge of the central portion in an elongated manner and has a width that is narrower than the width of the central portion and a length that is greater than the width of the first phalange portion, wherein the insert member has a peripheral edge defining a periphery of the insert member; and the peripheral edge comprises a front medial edge extending from a medial side of the central portion to a medial side of the first phalange portion and a front lateral edge extending from a lateral side of the central portion to a lateral side of the first phalange portion, and wherein the front medial edge has an outwardly-curved shape and the front lateral edge has an inwardly-curved shape.