Abstract: A recess portion 12 and a thick outer peripheral portion 13 are formed in an upper surface of a bottom plate 1. A recess portion 21 is formed in a lower surface of a cover 2. The recess portions 12 and 21 have configurations corresponding to a combination of a tarsal portion of a foot covering an area from a heel to substantially a center portion of a foot and a metatarsal portion of the foot covering an area from the center portion to roots of toes of the foot, respectively. A plurality of blades 11 are integrally formed on a surface of the recess portion 12, extend in directions perpendicular to a longitudinal direction of the bottom plate and are slanted toward a heel portion of the bottom plate. The welded portions 3 and 4 of the upper surface of the bottom plate 1 and the lower surface of the cover, which directly surround the respective recess portions and have uniform width, are welded together by a high frequency welder and fluid is sealed in a space defined by the recess portions 12 and 21.

Abstract: A bottom plate has its top surface formed with a recess with a plurality of slanted blades formed therein. A cover has a recess and an increased thickness portion formed around the recess and extending toward a marginal portion. A fluid is sealed in both the recesses. In the recess of the cover, fluid shock buffer blades are formed on at least a portion, which is urged by foot fingers and swelling foot finger roots, the blades being slanted in a direction perpendicular to the longitudinal direction of the cover. The marginal portion of the cover is fused to the marginal portion of the bottom plate.

Abstract: A mid-sole or sole of shoes for massaging the sole of a foot by stimulating it during walking includes recess portions on the upper surface of a bottom plate defined by a wall portion, a plurality of blades in the recess portions extending in a direction perpendicular to the longitudinal direction of the bottom plate and being slanted in the same direction, a flexible cover sealed at the peripheral end portion of the upper surface of the bottom plate, and liquid injected and filled in the space provided between the bottom plate and the cover.