충격흡수용 마라톤화(Cushioned Shoes) 개발을 위한 중창·하지의 충격흡수기능 연구 -마라톤화 연구의 과거 & 현재를 중심으로-

Abstract

The purpose of this study was to analyze impact absorption function of midsole in cushioned marathon shoes. The foot is made up of a complex interaction of bones, ligaments, and muscles. These structures help the foot alternate between being a mobile, flexible adaptor and a stable rigid lever. The foot is broken down into two functional parts, the forefoot and the rearfoot. Cushioned marathon shoes for high arches have generous cushioning for efficient and high-mileage runners. Cushioned marathon shoes are made for feet that have high arches or no excessive motion and don't roll inward or roll outward. This condition is known as underpronation. Especially, Cushioned marathon shoes are designed to reduce shock and generally have the softest (or most cushioned) midsoles and the least medial support. They are usually built on a semicurved or curved last to encourage foot motion, which is helpful for underpronators (who have rigid, immobile feet). Cushioning marathon shoes recommended for the high-arched runner, whose foot may roll outward (supinate) rather than the natural slight inward roll, or whose feet may be relatively rigid. Cushioning shoes emphasize flexibility and usually are built on a curved or semicurved last to encourage a normal motion of the foot. Cushioning shoes usually offer no medial (inner foot) support. Cushioned marathon shoes have the single-density midsole, which is stable and relatively firm for a cushioned shoe, stays the same. But the forefoot is more rounded, and the rearfoot now includes a new and supportive rearfoot cradle. A foam midsole, perhaps with layers of different densities, to provide cushioning and shock absorption. EVA (ethylene vinyl acetate) and PU (polyurethane), the materials from which these foams usually are made. EVA is slightly softer than PU. EVA and PU may be layered together in a shoe, or a shoe may have more than one density of EVA.