A movement assistance device comprising a first element for rigidly connecting the device to one foot of a user and transmitting a thrust force to said foot; and a second element linked to the first element by link means and intended to be in contact with the ground; the device further comprises means for transmitting a force from an exogenous energy source, to the first element and/or to the second element, in order to separate them from each other.

Footwear includes a fluid-filled bladder system having: (a) a foot-support bladder system, (b) a foot-securing bladder system, and (c) a fluid-flow control system for controlling fluid flow between these bladder systems. The fluid-filled bladder system may be changed between: (i) a foot-insertion configuration in which the foot-support bladder system contains a first volume of fluid (e.g., V.sub.1) and the foot-securing bladder system contains a second volume of fluid (e.g., V.sub.2), and (ii) a foot-securing configuration in which the foot-support bladder system contains a third volume of fluid (e.g., V.sub.3) and the foot-securing bladder system contains a fourth volume of fluid (e.g., V.sub.4), wherein V.sub.1>V.sub.3 and V.sub.2<V.sub.4. Additionally or alternatively, articles of footwear may include a friction reducing agent located at or near the foot-receiving opening to allow easier foot access, e.g., in a hands-free manner and/or without collapsing the upper.

An article of footwear is disclosed below as having an upper and a sole structure secured to the upper. The sole structure includes a perimeter chamber, a central chamber, and an outsole. The perimeter chamber extends adjacent to at least a portion of a lateral sidewall and a medial sidewall of the sole structure. The central chamber is positioned within a central area of the sole structure, the central area being located between the lateral sidewall and the medial sidewall. The outsole defines at least a portion of a lower surface of the sole structure, and has a perimeter section secured below the perimeter chamber and a central section secured below the central chamber. Various features may be incorporated into the sole structure. For example, the perimeter chamber may be spaced from the central chamber and the perimeter section may be spaced from the central section to define a gap extending upward and into the sole structure from the lower surface.

An article of footwear is disclosed below as having an upper and a sole structure secured to the upper. The sole structure includes a perimeter chamber, a central chamber, and an outsole. The perimeter chamber extends adjacent to at least a portion of a lateral sidewall and a medial sidewall of the sole structure. The central chamber is positioned within a central area of the sole structure, the central area being located between the lateral sidewall and the medial sidewall. The outsole defines at least a portion of a lower surface of the sole structure, and has a perimeter section secured below the perimeter chamber and a central section secured below the central chamber. Various features may be incorporated into the sole structure. For example, the perimeter chamber may be spaced from the central chamber and the perimeter section may be spaced from the central section to define a gap extending upward and into the sole structure from the lower surface.

An adjustable bladder system for an article of footwear is disclosed. The bladder system includes an outer bladder that may be inflated using an external pump. In addition, one or more tensile members may be disposed internally to the outer bladder to provide enhanced support. A valve member may also be disposed internally to the outer bladder. The valve member can include a contoured edge to provide a contoured shape for the outer bladder.

An adjustable bladder system for an article of footwear is disclosed. The bladder system includes an outer bladder that may be inflated using an external pump. A valve member may be disposed externally to the outer bladder. In addition, one or more tensile members may be disposed within the outer bladder to control deformation of the outer bladder during compression.

An article of footwear is provided having an elevated plate structure incorporated in the sole structure and optionally including a fluid-filled chamber. The elevated plate structure can include an upper plate and a plurality of legs extending downward toward the outsole. End portions of the legs can engage an upper region of the outsole. The elevated plate structure can form a cage region that can optionally include a fluid-filled chamber substantially disposed therein. The elevated plate structure can further include a lower plate disposed at an upper region of the outsole, which can form a lower portion of the cage region. Portions of the legs can be integrated with impact-attenuating members in the heel region in various configurations and can provide features for the impact-attenuating members, such as support, impact-attenuation and adjustable impact-attenuation features.

Footwear uppers include a footwear upper base formed from one or more component parts and including: (i) an instep region including at least one of a tongue base region or instep base region and (ii) a heel-containing region. A bladder is engaged with the footwear upper. The bladder includes: (i) at least a first instep chamber engaged with the instep region, (ii) at least a first heel and/or ankle support chamber engaged with the heel-containing region, and (iii) a first fluid line connecting the first instep chamber and the first heel and/or ankle support chamber and placing the first instep chamber in fluid communication with the first heel and/or ankle support chamber. Fluid moving from the first instep chamber to the first heel and/or ankle support chamber (e.g., under force applied by a footwear securing strap) provides further support for the wearer's heel and/or ankle.

Footwear uppers include a footwear upper base formed from one or more component parts and including: (i) an instep region including at least one of a tongue base region or instep base region and (ii) a heel-containing region. A bladder is engaged with the footwear upper. The bladder includes: (i) at least a first instep chamber engaged with the instep region, (ii) at least a first heel and/or ankle support chamber engaged with the heel-containing region, and (iii) a first fluid line connecting the first instep chamber and the first heel and/or ankle support chamber and placing the first instep chamber in fluid communication with the first heel and/or ankle support chamber. Fluid moving from the first instep chamber to the first heel and/or ankle support chamber (e.g., under force applied by a footwear securing strap) provides further support for the wearer's heel and/or ankle.

Footwear uppers include a footwear upper base formed from one or more component parts and including: (i) an instep region including at least one of a tongue base region or instep base region and (ii) a heel-containing region. A bladder is engaged with the footwear upper. The bladder includes: (i) at least a first instep chamber engaged with the instep region, (ii) at least a first heel and/or ankle support chamber engaged with the heel-containing region, and (iii) a first fluid line connecting the first instep chamber and the first heel and/or ankle support chamber and placing the first instep chamber in fluid communication with the first heel and/or ankle support chamber. Fluid moving from the first instep chamber to the first heel and/or ankle support chamber (e.g., under force applied by a footwear securing strap) provides further support for the wearer's heel and/or ankle.