An article of footwear includes an upper, an outsole attached to the upper, and a midsole. The outsole is attached to the upper and includes a ground-engaging surface and an inner surface disposed on an opposite side of the outsole than the ground-engaging surface. The midsole includes a footbed and a bottom surface disposed on an opposite side of the midsole than the footbed and opposing the inner surface of the outsole to define a cavity therebetween. The article of footwear also includes a casing received within the casing and defining an interior void. The interior void contains a first quantity of particulate matter movable relative to the casing and a second quantity of particulate matter attached to the casing.

Disclosed herein is a composite element comprising a textile and a hydrogel layer comprising a hydrogel material that is operably coupled to the textile, wherein a portion of the hydrogel layer extends through a first side of the textile, and at least partially into a core of the textile, but does not extend onto a second side of the textile. Also disclosed are sole structures and articles of athletic footwear incorporating the composite element, as well as methods of manufacturing such composite elements, sole structures, and articles of footwear.

A midsole may include an electrorheological (ER) fluid housing. The ER fluid housing may be located between top bottom surfaces of the midsole in at least a forefoot region of the midsole. The midsole may include a plate located over the ER fluid housing.

A bladder for an article of footwear includes a plate, a first tensile layer disposed adjacent to a first side of the plate, and a second tensile layer disposed on an opposite side of the plate from the first tensile layer, the second tensile layer joined to the first tensile layer through the plate by a plurality of inner bonds. The bladder additionally includes a first barrier layer disposed adjacent to the first tensile layer and joined to the first tensile layer by a plurality of first outer bonds to form a first chamber, one or more of the first outer bonds interposed between adjacent ones of the inner bonds.

A pair of shoes that includes a left foot shoe and a right foot shoe. Each of the shoes include an upper shoe portion and a sole coupled to the upper shoe portion. The sole provides an athletic positioning of a left big toe area of the left shoe at a lower position than a left heel area of the left shoe and at a lower position than an outer small toe area of the left shoe and wherein, from an inner edge to an outer edge of the left shoe, the left heel area has substantially no slope.

A method of forming a fluid-filled chamber for an article of footwear is provided and includes positioning a first sheet of material and a second sheet of material in a pressure chamber, increasing a fluid pressure within the pressure chamber to a first value, and coupling the first sheet of material to the second sheet of material within the pressure chamber to define a fluid-filled chamber defined by the first sheet of material and the second sheet of material and having a fluid pressure equal to the first value. The method also includes decreasing the fluid pressure within the pressure chamber to a second value.

Systems and methods are described for a shoe sole for relieving pressure from a wearer's metatarsal heads. In one aspect, a shoe sole comprises a shoe outer sole comprising a shaft region, a ball region, and a toe region. The shaft region underlies metatarsal shafts of the wearer and comprises a first lower surface, the ball region underlies metatarsal heads of the wearer and comprises a second lower surface, and the toe region underlies phalanges of the wearer and comprises a third lower surface. The second lower surface is raised relative to the first lower surface and the third lower surface.

A sole structure for an article of footwear includes a bladder having a plurality of tapered chambers including (a) a series of first tapered chambers tapering from a first end on a medial side of the bladder to a second end on a lateral side of the bladder, and (b) one or more second tapered chambers tapering from a first end on the lateral side of the bladder to a second end on the medial side of the bladder. Each of the one or more second tapered chambers is interposed between adjacent ones of the first tapered chambers. The sole structure also includes a chassis disposed on a first side of the bladder and having a plurality of first ribs each disposed between adjacent ones of the first tapered chambers and the second tapered chambers.

An interchangeable bootie system includes an article of footwear and a plurality of interchangeable booties. Each bootie includes a support system configured to provide targeted support to different regions of the foot. This allows a user to select a bootie that provides the desired type of support for an athletic activity. An interchangeable bootie system with midsole portions having different types of cushioning systems is also disclosed. This allows a user to select a bootie with the desired type of support and the desired type of cushioning for an athletic activity. An interchangeable bootie and midsole insert system is also disclosed. Each midsole insert fits inside a bootie and includes a cushioning system configured to provide targeted cushioning to different regions of the foot. This allows a user to select a desired type of cushioning for an athletic activity.

An article of footwear is provided having a pressurized fluid-filled chamber in the sole structure having a continuous perimeter weld and lacking an inflation channel. The chamber may be formed from opposing polymer sheets, a continuous perimeter weld lacking a weld channel bonding the sheets and forming an interior void between the sheets, and a fluid disposed within the interior void exerting outward pressure on the sheets. A method for making the chamber can include placing a pair of polymer sheets in an opposing arrangement, pressing opposing perimeter weld portions of the sheets against each other to form an airtight seal along a perimeter region of an interior void, supplying a flow of pressurized air between the opposing sheets into the interior void, and, while maintaining a desired fluid pressure, welding the perimeter weld portions of the sheets to each other. A high-frequency welder for forming chamber is also provided.