Abstract: An article of footwear having an upper (10) with a rear portion (14) flexible enough to allow the rear part of the sole (16) to lie flat under the heel of the foot during the walking stride, and flexible enough to permit unimpeded hindfoot inversion; a level sole (16); an insole (20) with a gripping material (18) bonded to its upper surface; and a midsole (22) that provides shock absorption for the heel and forefoot without springiness. Full range of motion of the foot, balance of the foot and body, and proprioceptive and tactile sensitivity of the foot are achieved.