Running shoes

A running shoe comprising an upper and a sole running the length of the shoe from the heel to the toe, the sole comprising an outsole and a midsole, and the midsole being constructed with a recess extending with an elongate slot-like cross-section generally parallel to the sole plane of the shoe fully across the width of the heel area, said recess being shaped asymmetrically with respect to the general longitudinal center line of the heel so as to have a major portion on the inner side of the heel terminating at a first opening in the inner side edge of the sole and a minor portion on the outer side of the heel terminating at a second opening in the outer side edge of the sole, said inner side opening being longer in the longitudinal heel-to-toe direction of the sole than the outer side opening, and first and second inserts removably inserted into said recess through said side openings in the sole, said inserts being of such dimensions as to fill the aforementioned recess sufficiently to provide adequate support and cushioning under running conditions and being of such design as to interlock within the midsole so as to prevent their expulsion from the midsole during running, and said inserts furthermore being of selectable and interchangeable hardness characteristics.

A running shoe comprising an outsole formed of relatively hard material and incorporating a tread pattern, a midsole formed of at least one layer of relatively soft shock-absorbent material, a heel wedge, and an upper, said midsole having formed therein in a region thereof which corresponds to the heel of the shoe a generally flat recess of longitudinally asymmetrical shape extending between and opening to opposite sides of the heel of the shoe with a larger part of the recess opening to the inside edge of the shoe and a lesser part opening to the outside edge of the shoe, and a first insert removably received in said larger recess part via the inside edge opening and a second insert removably received in the lesser recess part via the outside edge opening, said first and second inserts interlocking with each other within said recess and together being complementary in shape to said recess whereby the inserts are positively retained within the recess during running, and said inserts being selected from a range of inserts of different durometer hardnesses so as to customize the running shoe to the individual requirements of the user and in particular so as selectively to counter any tendency of the user towards over-pronation and over-supination.