US Patent 8713821 Athletic shoes having an upper whose fitting property is improved

The present invention relates to the upper U of an athletic shoe comprising a first opening 1 out of which the foot sticks upwards during wearing and a second opening 2 which is closed with a tongue. The two openings 1, 2 are continuous with each other, and the upper U comprises a medial side stretchable part 51 which covers a part of a medial side face of an arch of the foot, a lateral side stretchable part 50 which covers a part of a lateral side face of a ball of a little toe (a fifth toe), a front part 3 located forward of the two stretchable parts 50, 51 and a rear part 4 located backward of the two stretchable parts. Each of the stretchable parts 50, 51 is provided so as to essentially cross one of side faces of the upper U from a top surface of a sole S to the second opening 2. Young's modulus along the lengthwise direction L of the foot of each of the stretchable parts 50, 51 is set smaller than that of the front part 3 and the rear part 4.