Particulate foam with partial restriction

An article of footwear comprising:

• an upper;
• an outsole attached to the upper and including a ground-engaging surface;
• and
• a midsole disposed between the upper and the outsole and including a first surface, a second surface, and a series of walls each formed separately from the first surface and the second surface and including a first end fastened to the first surface and a second end opposite the first end and fastened to the second surface to define a series of channels extending substantially perpendicular to a longitudinal axis of the midsole and along an entire length of the midsole, adjacent ones of the channels (i) overlapping one another along both the length and a width of the midsole, (ii) being isolated from one another, and (iii) each receiving a quantity of particulate matter therein.