US Patent 7370443 Footwear item for racket sports

The invention relates to a footwear item that is designed for racket sports. The inventive item includes a sole that includes a dynamic element that stores and releases energy when the sole is subjected to lateral stresses. The dynamic element includes at least two pair of elastically deformable support parts which are located longitudinally on either side of the metatarsus support area of the sole and which extend opposite to one another such that a first pair extend on opposite sides of a longitudinal axis of the sole and toward an arch portion of the sole and the second pair extend on opposite sides of the longitudinal axis of the sole and toward a front part of the sole.