Particulate foam stacked casings

An article of footwear comprising:

• an upper;
• a midsole attached to the upper and including a footbed and a bottom surface disposed on an opposite side of the midsole than the footbed;
• an outsole having a ground-engaging surface, an inner surface disposed on an opposite side of the outsole than the ground-engaging surface, and a wall extending from the ground-engaging surface and surrounding the outsole, the outsole including a first groove disposed at the ground-engaging surface and defined by a first portion of the outsole extending in a direction toward the upper and a second groove disposed at the ground-engaging surface and defined by a second portion of the outsole extending in a direction toward the upper;
• a first pair of casings each containing particulate matter and having a thickness extending substantially perpendicular to a longitudinal axis of the outsole, the first pair of casings arranged in a layered configuration and received within a cavity bounded by the wall of the outsole and between the bottom surface and the inner surface;
• a second pair of casings each containing particulate matter and having a thickness extending substantially perpendicular to the longitudinal axis of the outsole, the second pair of casings arranged in a layered configuration and received within the cavity bounded by the wall of the outsole and between the bottom surface and the inner surface, the second pair of casings being isolated from the first pair of casings;
• and
• a third pair of casings each containing particulate matter and having a thickness extending substantially perpendicular to the longitudinal axis of the outsole, the third pair of casings arranged in a layered configuration and received within the cavity bounded by the wall of the outsole and between the bottom surface and the inner surface, the third pair of casings (i) disposed between the first pair of casings and the second pair of casings, (ii) separated from the first pair of casings by the first portion of the outsole, and (iii) separated from the second pair of casings by the second portion of the outsole.