Abstract: A shoe sole or insole incorporates an inflatable cell structure therein. The cells are sized and positioned to alter the angular orientation of a wearer's foot relative to a supporting surface upon inflation. A variable position valve causes the cells to inflate and deflate in a random or pseudo-random sequence. Such a sole when worn while standing on or traversing a flat, even, and unvarying terrain enhances the wearer's comfort, reduces fatigue and promotes control of veinous blood pressure in the legs.