Corrective shoe sole structures using a contour greater than the theoretically ideal stability plan

• US 6,360,453 B1
• Filed: 05/30/1995
• Issued: 03/26/2002
• Est. Priority Date: 10/03/1989
• Status: Expired due to Fees

• Current Assignee: Anatomic Research Inc.
• Original Assignee: Anatomic Research Inc.
• Inventors: Ellis, Frampton E. III
• Primary Examiner(s): STASHICK, ANTHONY D
• Application Number:
  US08/452,490
• Time in Patent Office: 2,492 Days
• Field of Search: 36/32.R, 36/25.R, 36/30.R, 36/31, 361/14, 36/88, 36/91, 36/28, 361/63, 361/16, 36/115, 36/11
• US Class Current: 36/25.00R
• CPC Class Codes: A43B 13/12 Soles with several layers of different materials
• CPC Class Codes: A43B 13/143 provided with wedged, concave or convex end portions, e.g. for improving roll-off of the foot
• CPC Class Codes: A43B 13/145 Convex portions, e.g. with a bump or projection, e.g. 'Masai' type shoes
• CPC Class Codes: A43B 13/146 Concave end portions, e.g. with a cavity or cut-out portion
• CPC Class Codes: A43B 13/18 Resilient soles skating boots provided with resilient means A43B5/1658
• CPC Class Codes: A43B 5/00 Footwear for sporting purposes non-skid devices, e.g. ice-spurs or studs for football shoes, A43C15/00

Abstract

A shoe having a sole contour which follows a theoretically ideal stability plane as a basic concept, but which deviates outwardly therefrom to provide greater than natural stability. Thickness variations outwardly from the stability plane are disclosed, along with density variations to achieve a similar greater than natural stability.

Claims

1. A sole suitable for an athletic shoe comprising:

a sole outer surface;

a sole inner surface;

a sole forefoot area at a location substantially corresponding to the location of a forefoot of an intended wearer'"'"'s foot when inside the shoe;

a sole heel area at a location substantially corresponding to the location of a heel of an intended wearer'"'"'s foot when inside the shoe;

a sole midtarsal area at a location substantially corresponding to the area between the heel and the forefoot of the intended wearer'"'"'s foot when inside the shoe;

a midsole having three different densities;

the sole surfaces of the sole for an athletic shoe defining a sole medial side, a sole lateral side, and a sole middle portion between the sole medial and lateral sides,

the sole outer surface of one of the lateral and medial sides comprising a concavely rounded portion extending at least below a level of a lowest point of the sole inner surface, as viewed in a shoe sole frontal plane cross-section of the sole heel area when the shoe sole is upright and in an unloaded condition, the concavity of the concavely rounded portion existing with respect to an inner section of the shoe sole directly adjacent to the concavely rounded outer surface portion,

the sole inner surface of the side of the shoe sole which has a concavely rounded outer surface portion comprising a convexly rounded portion, as viewed in the shoe sole frontal plane cross-section when the shoe sole is upright and in an unloaded condition, the convexity of the convexly rounded portion existing with respect to a section of the shoe sole directly adjacent to the convexly rounded inner surface portion; and

a sole side portion located between the convexly rounded portion of the sole inner surface and the concavely rounded portion of the sole outer surface having a thickness measured from the sole inner surface to the sole outer surface that is greater than a least thickness of the sole middle portion measured from the sole inner surface to the sole outer surface, as viewed in the frontal plane cross-section when the shoe sole is upright and in an unloaded condition.

2. The sole as set forth in claim 1, wherein the midsole comprises portions with first, second and third densities, the portion having the first density being located adjacent a side edge of the shoe sole and the portion having the second density being located adjacent to a center line of the shoe sole, all as viewed in the frontal plane cross-section when the shoe sole is upright and in an unloaded condition, said frontal plane cross-section being located in the heel area of the shoe sole, and

the first density is greater than the second density when the shoe sole is in an unloaded condition.

3. The sole as set forth in claim 1, wherein:

the midsole comprises portions of first, second and third densities, said portion of first density having a lesser density than said portion of second density, said area of first density being located in a heel area of the shoe sole, and

said portion of second density being located adjacent said portion of first density.

4. The sole as set forth in claim 3, wherein both the sole lateral side and the sole medial side comprise a convexly rounded inner surface portion and a concavely rounded outer surface portion, as viewed in the shoe sole frontal plane cross-section when the shoe sole is upright and in an unloaded condition, the convexity of the convexly rounded inner surface portion existing with respect to a section of the shoe sole directly adjacent to the convexly rounded inner surface portion, and the concavity of the concavely rounded outer surface portion existing with respect to an inner section of the shoe sole directly adjacent to the concavely rounded outer surface portion.

5. The shoe sole as set forth in claim 3, wherein said concavely rounded portion of the sole outer surface extends down to near a lowest point of one of the lateral and medial sides of the shoe sole, as viewed in the shoe sole frontal plane cross-section when the shoe sole is upright and in an unloaded condition, and

the thickness of the side portion of the shoe sole being defined as a length of a line starting at a starting point on the sole inner surface and extending to the sole outer surface in a direction perpendicular to a line tangent to the sole inner surface at the starting point, all as viewed in a shoe sole frontal plane cross-section when the shoe sole is upright and in an unloaded condition.

6. The sole as set forth in claim 3, wherein one of said portions of first and second density in the midsole has a greater thickness in the side portion than a thickness of the same midsole portion in the sole middle portion, as viewed in the shoe sole frontal plane cross-section when the shoe sole is upright and in an unloaded condition.

7. The shoe sole set forth in claim 3, wherein the concavely rounded portion of the sole outer surface extends through a sidemost extent of the sole outer surface of the sole side having the concavely rounded outer surface portion, as viewed in the shoe sole frontal plane cross-section when the shoe sole is upright and in an unloaded condition.

8. The shoe sole as set forth in claim 1, wherein the at least one shoe sole side having a concavely rounded outer surface portion extends up to a level above the lowest point of the inner surface of the shoe sole, as viewed in a shoe sole frontal plane cross-section of the sole heel portion when the shoe sole is upright and in an unloaded condition.

9. The shoe sole as set forth in claim 8, wherein the thickness of the at least one shoe sole side having a concavely rounded outer surface portion increases from a first thickness at an uppermost point on the shoe sole side to a greater thickness at a portion of said shoe sole side below said uppermost point, as viewed in a shoe sole frontal plane cross-section of the sole heel portion when the shoe sole is upright and in an unloaded condition;

and

the thickness of the shoe sole being defined as the length of a line starting at a starting point on the sole inner surface and extending to a point on the sole outer surface in a direction perpendicular to a line tangent to the sole inner surface at the starting point, as viewed in a shoe sole frontal plane cross-section of the sole heel portion when the shoe sole is upright and in an unloaded condition.

10. The shoe sole as set forth in claim 1, wherein the concavely rounded sole outer surface portion extends from an uppermost portion of the shoe sole side to a level below the lowest point of the sole inner surface, as viewed in a shoe sole frontal plane cross-section of the sole heel portion when the shoe sole is upright and in an unloaded condition.

11. The shoe sole as set forth in claim 1, wherein the portions of the midsole having three different densities can be viewed in a single frontal plane cross-section when the shoe sole is upright and in an unloaded condition.

12. The shoe sole as set forth in claim 1, wherein the concavely rounded sole outer surface portion extends through a lowermost point of the shoe sole side, as viewed in a shoe sole frontal plane cross-section of the sole heel portion when the shoe sole is upright and in an unloaded condition.

13. The shoe sole as set forth in claim 1, wherein each shoe sole side comprises a sidemost section of the shoe sole located outside of a straight vertical line drawn at the sidemost extent of the inner surface of the midsole and at least a portion of the midsole extends into the sidemost section of the at least one shoe sole side having a concavely rounded outer surface portion, as viewed in a shoe sole frontal plane cross-section of the sole heel portion when the shoe sole is upright and in an unloaded condition.

14. The shoe sole as set forth in claim 13, wherein the thickness of the portion of the midsole which extends into the sidemost section of the at least one shoe sole side having a concavely rounded outer surface portion increases from a first thickness at an uppermost point on the midsole to a greater thickness at a portion of said midsole below said uppermost point, as viewed in a shoe sole frontal plane cross-section of the sole heel portion when the shoe sole is upright and in an unloaded condition;

and

the thickness of the midsole portion being defined as the length of a line starting at a starting point on the inner surface of the midsole portion and extending to an outer surface of the midsole portion in a direction perpendicular to a line tangent to the inner surface of the midsole portion at the starting point, as viewed in a shoe sole frontal plane cross-section of the sole heel portion when the shoe sole is upright and in an unloaded condition.

15. The shoe sole as set forth in claim 1, wherein a midsole portion of greatest density is located adjacent a side edge of the shoe sole, a midsole portion of least density is located adjacent a centerline of the shoe sole, and a midsole portion of intermediate density is located between the midsole portion of greatest density and the midsole portion of least density, as viewed in a frontal plane cross-section when the shoe sole is upright and in an unloaded condition.

16. The shoe sole as set forth in claim 11, further comprising a second midsole portion of greatest density adjacent a second side edge of the shoe sole and a second midsole portion of intermediate density located between the second midsole portion of greatest density and the midsole portion of least density, as viewed in a frontal plane cross-section when the shoe sole is upright and in an unloaded condition.

17. The shoe sole as set forth in claim 1, wherein a midsole portion of least density is located adjacent a centerline of the shoe sole, a midsole portion of greatest density is located on a first side of the midsole portion of least density, and a midsole portion of intermediate density is located on a second side of the midsole portion of least density, as viewed in a frontal plane cross-section when the shoe sole is upright and in an unloaded condition.

18. A shoe sole as claimed in claim 17, wherein the midsole portions of intermediate and greatest density are also located adjacent to first and second side edges of the shoe sole, as viewed in a frontal plane cross-section when the shoe sole is upright and in an unloaded condition.

30. The shoe sole as set forth in claim 1, wherein the concavely rounded portion of the sole outer surface extends down to near a lowest point of one of the lateral and medial sides of the shoe sole, as viewed in the shoe sole frontal plane cross-section of the sole heel portion when the shoe sole is upright and in an unloaded condition.

19. A sole for an athletic shoe comprising:

a sole outer surface;

a sole inner surface;

a sole forefoot area at a location substantially corresponding to the location of a forefoot of an intended wearer'"'"'s foot when inside the shoe;

a sole heel area at a location substantially corresponding to the location of a heel of an intended wearer'"'"'s foot when inside the shoe;

a sole midtarsal area at a location substantially corresponding to the area between the heel and the forefoot of the intended wearer'"'"'s foot when inside the shoe;

a midsole having three different firmnesses;

the sole surfaces of the sole for an athletic shoe defining a sole medial side, a sole lateral side, and a sole middle portion between the sole medial and lateral sides,

the sole outer surface of one of the lateral and medial sides comprising a concavely rounded portion extending at least below a level of a lowest point of the sole inner surface, as viewed in a shoe sole frontal plane cross-section of the sole heel area when the shoe sole upright and in an unloaded condition, the concavity of the concavely rounded portion existing with respect to an inner section of the shoe sole directly adjacent to the concavely rounded outer surface portion,

the sole inner surface of the side of the shoe sole which has a concavely rounded outer surface portion comprising a convexly rounded portion, as viewed in the shoe sole frontal plane cross-section of the sole heel area when the shoe sole is upright and in an unloaded condition, the convexity of the convexly rounded portion existing with respect to a section of the shoe sole directly adjacent to the convexly rounded inner surface portion; and

a sole side portion located between the convexly rounded portion of the sole inner surface and the concavely rounded portion of the sole outer surface having a thickness measured from the sole inner surface of the sole outer surface that is greater than a least thickness of the sole middle portion measured from the sole inner surface to the sole outer surface, as viewed in the frontal plane cross-section when the shoe sole is upright and in an unloaded condition.

20. The shoe sole as set forth in claim 19, wherein the at least one shoe sole side having a concavely rounded outer surface portion extends up to a level above the lowest point of the inner surface of the shoe sole, as viewed in a shoe sole frontal plane cross-section of the sole heel portion when the shoe sole is upright and in an unloaded condition.

21. The shoe sole as set forth in claim 20, wherein the thickness of the at least one shoe sole side having a concavely rounded outer surface portion increases from a first thickness at an uppermost point on the shoe sole side to a greater thickness at a portion of said shoe sole side below said uppermost point, as viewed in a shoe sole frontal plane cross-section of the sole heel portion when the shoe sole is upright and in an unloaded condition;

and

the thickness of the shoe sole being defined as the length of a line starting at a starting point on the sole inner surface and extending to the sole outer surface in a direction perpendicular to a line tangent to the sole inner surface at the starting point, as viewed in a shoe sole frontal plane cross-section of the sole heel portion when the shoe sole is upright and in an unloaded condition.

22. The shoe sole as set forth in claim 19, wherein the concavely rounded sole outer surface portion extends from an uppermost portion of the shoe sole side to below a level of the lowest point of the sole inner surface, as viewed in a shoe sole frontal plane cross-section of the sole heel portion when the shoe sole is upright and in an unloaded condition.

23. The shoe sole as set forth in claim 19, wherein the concavely rounded sole outer surface portion extends through a sidemost extent of the shoe sole side, as viewed in a shoe sole frontal plane cross-section of the sole heel portion when the shoe sole is upright and in an unloaded condition.

24. The shoe sole as set forth in claim 19, wherein the concavely rounded sole outer surface portion extends through a lowermost point of the shoe sole side, as viewed in a shoe sole frontal plane cross-section of the sole heel portion when the shoe sole is upright and in an unloaded condition.

25. The shoe sole as set forth in claim 19, wherein each shoe sole side comprises a sidemost section of the shoe sole located outside of a straight vertical line drawn at the sidemost extent of the inner surface of the midsole and at least a portion of the midsole extends into the sidemost section of the at least one shoe sole side having a concavely rounded outer surface portion, as viewed in a shoe sole frontal plane cross-section of the sole heel portion when the shoe sole is upright and in an unloaded condition.

26. The shoe sole as set forth in claim 25, wherein the thickness of the portion of the midsole which extends into the sidemost section of the at least one shoe sole side having a concavely rounded outer surface portion increases from a first thickness at an uppermost point on the midsole to a greater thickness at a portion of said midsole below said uppermost point, as viewed in a shoe sole frontal plane cross-section of the sole heel portion when the shoe sole is upright and in an unloaded condition;

and

the thickness of the midsole portion being defined as the length of a line starting at a starting point on the inner surface of the midsole portion and extending to an outer surface of the midsole portion in a direction perpendicular to a line tangent to the inner surface of the midsole portion at the starting point, as viewed in a shoe sole frontal plane cross-section of the sole heel portion when the shoe sole is upright and in an unloaded condition.

27. The shoe sole as set forth in claim 19, wherein the midsole has portions having first, second and third firmnesses, the portion of the midsole having the first firmness is located adjacent to a side edge of the shoe sole and the portion of the midsole having the second firmness is located adjacent to a center line of the shoe sole, all as viewed in the frontal plane cross-section of the sole heel portion when the shoe sole is upright and in an unloaded condition;

and

the first firmness is firmer than the second firmness during a shoe sole unloaded condition.

28. The shoe sole as set forth in claim 27, wherein the thickness of the side portion of the shoe sole is defined as the length of a line starting at a starting point on the sole inner surface and extending to the sole outer surface in a direction perpendicular to a line tangent to the sole inner surface at the starting point, all as viewed in a shoe sole frontal plane cross-section when the shoe sole is upright and in an unloaded condition.

29. The shoe sole as set forth in claim 19, wherein the midsole comprises portions with first, second and third firmnesses, said portion of first firmness having a lesser firmness than said portion of second firmness, said portion of lesser firmness being located in a heel section of the shoe sole, and said portion of greater firmness being located adjacent to said portion of lesser firmness.

31. The shoe sole as set forth in claim 19, wherein both the sole lateral side and the sole medial side comprise a convexly rounded inner surface portion and a concavely rounded outer surface portion, as viewed in the shoe sole frontal plane cross-section when the shoe sole is upright and in an unloaded condition.

32. The shoe sole as set forth in claim 19, wherein the midsole comprises portions with first and second firmnesses, and one of said midsole portions of first and second firmness has a greater thickness in the side portion than a thickness of the same midsole portion in the sole middle portion, as viewed in the shoe sole frontal plane cross-section when the shoe sole is upright and in an unloaded condition.

33. The shoe sole as set forth in claim 19, wherein the portions of the midsole having three different firmnesses can be viewed in a single frontal plane cross-section when the shoe sole is upright and in an unloaded condition.

34. The shoe sole as set forth in claim 19, wherein a midsole portion of greatest firmness is located adjacent a side edge of the shoe sole, a midsole portion of least firmness is located adjacent a centerline of the shoe sole, and a midsole portion of intermediate firmness is located between the midsole portion of greatest firmness and the midsole portion of least firmness, as viewed in a frontal plane cross-section when the shoe sole is upright and in an unloaded condition.

35. The shoe sole as set forth in claim 34, further comprising a second midsole portion of greatest firmness adjacent a second side edge of the shoe sole and a second midsole portion of intermediate firmness located between the second midsole portion of greatest firmness and the midsole portion of least firmness, as viewed in a frontal plane cross-section when the shoe sole is upright and in an unloaded condition.

36. The shoe sole as set forth in claim 19, wherein a midsole portion of least firmness is located adjacent a centerline of the shoe sole, a midsole portion of greatest firmness is located on a first side of the midsole portion of least firmness, and a midsole portion of intermediate firmness is located on a second side of the midsole portion of least firmness, as viewed in a frontal plane cross-section when the shoe sole is upright and in an unloaded condition.

37. A shoe sole as claimed in claim 36, wherein the midsole portions of intermediate and greatest firmness are also located adjacent to first and second side edges of the shoe sole, as viewed in a frontal plane cross-section when the shoe sole is upright and in an unloaded condition.

38. A sole for an athletic shoe comprising:

a sole outer surface;

a sole inner surface;

a sole forefoot area at a location substantially corresponding to the location of a forefoot of an intended wearer'"'"'s foot when inside the shoe;

a sole heel area at a location substantially corresponding to the location of a heel of an intended wearer'"'"'s foot when inside the shoe;

a sole midtarsal area at a location substantially corresponding to the area between the heel and the forefoot of the intended wearer'"'"'s foot when inside the shoe;

a midsole;

the sole surfaces of the sole for an athletic shoe defining a sole medial side, a sole lateral side, and a sole middle portion between the sole medial and lateral sides,

the sole outer surface of one of the lateral and medial sides comprising a concavely rounded portion extending at least below a level of a lowest point of the sole inner surface, as viewed in a shoe sole frontal plane cross-section of the sole heel area when the shoe sole is upright and in an unloaded condition, the concavity of the concavely rounded portion existing with respect to an inner section of the shoe sole directly adjacent to the concavely rounded outer surface portion,

the sole inner surface of the side of the shoe sole which has a concavely rounded outer surface portion comprising a convexly rounded portion, as viewed in the shoe sole frontal plane cross-section when the shoe sole is upright and in an unloaded condition, the convexity of the convexly rounded portion existing with respect to a section of the shoe sole directly adjacent to the convexly rounded inner surface portion; and

a rounded sole side portion located between the convexly rounded portion of the sole inner surface and the concavely rounded portion of the sole outer surface having a thickness measured from the sole inner surface to the sole outer surface that is greater than a least thickness of the sole middle portion measured from the sole inner surface to the sole outer surface, as viewed in the frontal plane cross-section when the shoe sole is upright and in an unloaded condition;

wherein the midsole comprises midsole portions of first and second densities, said midsole portion of first density having a lesser density than said midsole portion of second density, said area of lesser density being located in a heel area of the shoe sole and said midsole portion of greater density being located adjacent said midsole portion of lesser density; and

said midsole portions of first and second density each have a thickness that tapers from a greater thickness to a lesser thickness, as viewed a frontal plane cross-section when the shoe sole is upright and in an unloaded condition.

39. The shoe sole as set forth in claim 38, wherein the first of said midsole portions is located below the second of said midsole portions, as viewed a frontal plane cross-section when the shoe sole is upright and in an unloaded condition.

40. The shoe sole as set forth in claim 38, wherein the at least one shoe sole side having a concavely rounded outer surface portion extends up to a level above the lowest point of the inner surface of the shoe sole, as viewed in a shoe sole frontal plane cross-section of the sole heel portion when the shoe sole is upright and in an unloaded condition.

41. The shoe sole as set forth in claim 38, wherein the thickness of the at least one shoe sole side having a concavely rounded outer surface portion increases from a first thickness at an uppermost point on the shoe sole side to a greater thickness at a portion of said shoe sole side below said uppermost point, as viewed in a shoe sole frontal plane cross-section of the sole heel portion when the shoe sole is upright and in an unloaded condition;

and

the thickness of the shoe sole being defined as the length of a line starting at a starting point on the sole inner surface and extending to the sole outer surface in a direction perpendicular to a line tangent to the sole inner surface at the starting point, as viewed in a shoe sole frontal plane cross-section of the sole heel portion when the shoe sole is upright and in an unloaded condition.

42. The shoe sole as set forth in claim 41, wherein the concavely rounded sole outer surface portion extends through a sidemost extent of the shoe sole side, as viewed in a shoe sole frontal plane cross-section of the sole heel portion when the shoe sole is upright and in an unloaded condition;

each shoe sole side comprises a sidemost section of the shoe sole located outside of a straight vertical line drawn at the sidemost extent of the inner surface of the midsole and at least a portion of the midsole extends into the sidemost section of the at least one shoe sole side having a concavely rounded outer surface portion, as viewed in a shoe sole frontal plane cross-section of the sole heel portion when the shoe sole is upright and in an unloaded condition;

the two midsole portions having different densities can be viewed in a single frontal plane cross-section of the sole heel portion when the shoe sole is upright and in an unloaded condition; and

the midsole portion having the first density is located adjacent to a side edge of the shoe sole and the midsole portion having the second density is located adjacent to a center line of the shoe sole, as viewed in the frontal plane cross-section of the sole heel portion when the shoe sole is upright and in an unloaded condition.

43. The shoe sole as set forth in claim 38, wherein the concavely rounded sole outer surface portion extends from an uppermost portion of the shoe sole side to below a level of the lowest point of the sole inner surface, as viewed in a shoe sole frontal plane cross-section of the sole heel portion when the shoe sole is upright and in an unloaded condition.

44. The shoe sole as set forth in claim 38, wherein the concavely rounded sole outer surface portion extends through a sidemost extent of the shoe sole side, as viewed in a shoe sole frontal plane cross-section of the sole heel portion when the shoe sole is upright and in an unloaded condition.

45. The shoe sole as set forth in claim 38, wherein the concavely rounded sole outer surface portion extends through a lowermost point of the shoe sole side, as viewed in a shoe sole frontal plane cross-section of the sole heel portion when the shoe sole is upright and in an unloaded condition.

46. The shoe sole as set forth in claim 38, wherein each shoe sole side comprises a sidemost section of the shoe sole located outside of a straight vertical line drawn at the sidemost extent of the inner surface of the midsole and at least a portion of the midsole extends into the sidemost section of the at least one shoe sole side having a concavely rounded outer surface portion, as viewed in a shoe sole frontal plane cross-section of the sole heel portion when the shoe sole is upright and in an unloaded condition.

47. The shoe sole as set forth in claim 38, wherein the thickness of the portion of the midsole which extends into the sidemost section of the at least one shoe sole side having a concavely rounded outer surface portion increases from a first thickness at an uppermost point on the midsole to a greater thickness at a portion of said midsole below said uppermost point, as viewed in a shoe sole frontal plane cross-section of the sole heel portion when the shoe sole is upright and in an unloaded condition;

and

the thickness of the midsole portion being defined as the length of a line starting at a starting point on the inner surface of the midsole portion and extending to an outer surface of the midsole portion in a direction perpendicular to a line tangent to the inner surface of the midsole portion at the starting point, as viewed in a shoe sole frontal plane cross-section of the sole heel portion when the shoe sole is upright and in an unloaded condition.

48. The shoe sole as set forth in claim 38, wherein the midsole portion having the first density is located adjacent to a side edge of the shoe sole and the midsole portion having the second density is located adjacent to a center line of the shoe sole, all as viewed in the frontal plane cross-section of the sole heel portion when the shoe sole is upright and in an unloaded condition.

49. The shoe sole as set forth in claim 38, wherein the concavely rounded portion of the sole outer surface extends down to near a lowest point of one of the lateral and medial sides of the shoe sole, as viewed in the shoe sole frontal plane cross-section of the sole heel portion when the shoe sole is upright and in an unloaded condition.

50. The shoe sole as set forth in claim 38, wherein both the sole lateral side and the sole medial side comprise a convexly rounded inner surface portion and a concavely rounded outer surface portion, as viewed in the shoe sole frontal plane cross-section when the shoe sole is upright and in an unloaded condition.

51. The shoe sole as set forth in claim 38, wherein the two midsole portions having different densities can be viewed in a single frontal plane cross-section when the shoe sole is upright and in an unloaded condition.

52. A shoe sole as claimed in claim 38, wherein a first of said midsole portions of first and second density has a thickness that tapers from a greater thickness in the side portion of the shoe sole to a lesser thickness at a location closer to the centerline of the shoe sole, as viewed a frontal plane cross-section when the shoe sole is upright and in an unloaded condition.

53. A shoe sole as claimed in claim 52, wherein a second of said midsole portions of first and second firmness has a thickness that tapers from a lesser thickness in a side portion of the shoe sole to a greater thickness at a location closer to the centerline of the shoe sole, as viewed a frontal plane cross-section when the shoe sole is upright and in an unloaded condition.

54. A sole for an athletic shoe comprising:

a sole outer surface;

a sole inner surface;

a sole forefoot area at a location substantially corresponding to the location of a forefoot of an intended wearer'"'"'s foot when inside the shoe;

a sole heel area at a location substantially corresponding to the location of a heel of an intended wearer'"'"'s foot when inside the shoe;

a sole midtarsal area at a location substantially corresponding to the area between the heel and the forefoot of the intended wearer'"'"'s foot when inside the shoe;

a midsole;

the sole surfaces of the sole for an athletic shoe defining a sole medial side, a sole lateral side, and a sole middle portion between the sole medial and lateral sides,

the sole outer surface of one of the lateral and medial sides comprising a concavely rounded portion extending at least below a level of a lowest point of the sole inner surface, as viewed in a shoe sole frontal plane cross-section of the sole heel area when the shoe sole is upright and in an unloaded condition, the concavity of the concavely rounded portion existing with respect to an inner section of the shoe sole directly adjacent to the concavely rounded outer surface portion,

the sole inner surface of the side of the shoe sole which has a concavely rounded outer surface portion comprising a convexly rounded portion, as viewed in the shoe sole frontal plane cross-section when the shoe sole is upright and in an unloaded condition, the convexity of the convexly rounded portion existing with respect to a section of the shoe sole directly adjacent to the convexly rounded inner surface portion; and

a rounded sole side portion located between the convexly rounded portion of the sole inner surface and the concavely rounded portion of the sole outer surface having a thickness measured from the sole inner surface to the sole outer surface that is greater than a least thickness of the sole middle portion measured from the sole inner surface to the sole outer surface, as viewed in the frontal plane cross-section when the shoe sole is upright and in an unloaded condition;

wherein the midsole comprises midsole portions of first and second firmnesses, said midsole portion of first firmness having a lesser firmness than said midsole portion of second firmness, said area of lesser firmness being located in a heel area of the shoe sole and said midsole portion of greater firmness being located adjacent said midsole portion of lesser firmness; and

said midsole portions of first and second firmness each have a thickness that tapers from a greater thickness to a lesser thickness, as viewed a frontal plane cross-section when the shoe sole is upright and in an unloaded condition.

55. The shoe sole as set forth in claim 54, wherein the first of said midsole portions is located below the second of said midsole portions, as viewed a frontal plane cross-section when the shoe sole is upright and in an unloaded condition.

56. The shoe sole as set forth in claim 54, wherein the at least one shoe sole side having a concavely rounded outer surface portion extends up to a level above the lowest point of the inner surface of the shoe sole, as viewed in a shoe sole frontal plane cross-section of the sole heel portion when the shoe sole is upright and in an unloaded condition.

57. The shoe sole as set forth in claim 54, wherein the thickness of the at least one shoe sole side having a concavely rounded outer surface portion increases from a first thickness at an uppermost point on the shoe sole side to a greater thickness at a portion of said shoe sole side below said uppermost point, as viewed in a shoe sole frontal plane cross-section of the sole heel portion when the shoe sole is upright and in an unloaded condition;

and

the thickness of the shoe sole being defined as the length of a line starting at a starting point on the sole inner surface and extending to the sole outer surface in a direction perpendicular to a line tangent to the sole inner surface at the starting point, as viewed in a shoe sole frontal plane cross-section of the sole heel portion when the shoe sole is upright and in an unloaded condition.

58. The shoe sole as set forth in claim 57, wherein the concavely rounded sole outer surface portion extends through a sidemost extent of the shoe sole side, as viewed in a shoe sole frontal plane cross-section of the sole heel portion when the shoe sole is upright and in an unloaded condition;

each shoe sole side comprises a sidemost section of the shoe sole located outside of a straight vertical line drawn at the sidemost extent of the inner surface of the midsole and at least a portion of the midsole extends into the sidemost section of the at least one shoe sole side having a concavely rounded outer surface portion, as viewed in a shoe sole frontal plane cross-section of the sole heel portion when the shoe sole is upright and in an unloaded condition;

the two midsole portions having different firmnesses can be viewed in a single frontal plane cross-section of the sole heel portion when the shoe sole is upright and in an unloaded condition; and

the midsole portion having the first firmness is located adjacent to a side edge of the shoe sole and the midsole portion having the second firmness is located adjacent to a center line of the shoe sole, as viewed in the frontal plane cross-section of the sole heel portion when the shoe sole is upright and in an unloaded condition.

59. The shoe sole as set forth in claim 54, wherein the concavely rounded sole outer surface portion extends from an uppermost portion of the shoe sole side to below a level of the lowest point of the sole inner surface, as viewed in a shoe sole frontal plane cross-section of the sole heel portion when the shoe sole is upright and in an unloaded condition.

60. The shoe sole as set forth in claim 54, wherein the concavely rounded sole outer surface portion extends through a sidemost extent of the shoe sole side, as viewed in a shoe sole frontal plane cross-section of the sole heel portion when the shoe sole is upright and in an unloaded condition.

61. The shoe sole as set forth in claim 54, wherein the concavely rounded sole outer surface portion extends through a lowermost point of the shoe sole side, as viewed in a shoe sole frontal plane cross-section of the sole heel portion when the shoe sole is upright and in an unloaded condition.

62. The shoe sole as set forth in claim 54, wherein each shoe sole side comprises a sidemost section of the shoe sole located outside of a straight vertical line drawn at the sidemost extent of the inner surface of the midsole and at least a portion of the midsole extends into the sidemost section of the at least one shoe sole side having a concavely rounded outer surface portion, as viewed in a shoe sole frontal plane cross-section of the sole heel portion when the shoe sole is upright and in an unloaded condition.

63. The shoe sole as set forth in claim 54, wherein the thickness of the portion of the midsole which extends into the sidemost section of the at least one shoe sole side having a concavely rounded outer surface portion increases from a first thickness at an uppermost point on the midsole to a greater thickness at a portion of said midsole below said uppermost point, as viewed in a shoe sole frontal plane cross-section of the sole heel portion when the shoe sole is upright and in an unloaded condition;

and

the thickness of the midsole portion being defined as the length of a line starting at a starting point on the inner surface of the midsole portion and extending to an outer surface of the midsole portion in a direction perpendicular to a line tangent to the inner surface of the midsole portion at the starting point, as viewed in a shoe sole frontal plane cross-section of the sole heel portion when the shoe sole is upright and in an unloaded condition.

64. The shoe sole as set forth in claim 54, wherein the midsole portion having the first firmness is located adjacent to a side edge of the shoe sole and the midsole portion having the second firmness is located adjacent to a center line of the shoe sole, all as viewed in the frontal plane cross-section of the sole heel portion when the shoe sole is upright and in an unloaded condition.

65. The shoe sole as set forth in claim 54, wherein the concavely rounded portion of the sole outer surface extends down to near a lowest point of one of the lateral and medial sides of the shoe sole, as viewed in the shoe sole frontal plane cross-section of the sole heel portion when the shoe sole is upright and in an unloaded condition.

66. The shoe sole as set forth in claim 54, wherein both the sole lateral side and the sole medial side comprise a convexly rounded inner surface portion and a concavely rounded outer surface portion, as viewed in the shoe sole frontal plane cross-section when the shoe sole is upright and in an unloaded condition.

67. The shoe sole as set forth in claim 54, wherein the two midsole portions having different firmnesses can be viewed in a single frontal plane cross-section when the shoe sole is upright and in an unloaded condition.

68. A shoe sole as claimed in claim 54, wherein a first of said midsole portions of first and second firmness has a thickness that tapers from a greater thickness in the side portion of the shoe sole to a lesser thickness at a location closer to the centerline of the shoe sole, as viewed a frontal plane cross-section when the shoe sole is upright and in an unloaded condition.

69. A shoe sole as claimed in claim 68, wherein a second of said midsole portions of first and second firmness has a thickness that tapers from a lesser thickness in a side portion of the shoe sole to a greater thickness at a location closer to the centerline of the shoe sole, as viewed a frontal plane cross-section when the shoe sole is upright and in an unloaded condition.