Prosthetic foot with variable medial/lateral stiffness

1. A prosthetic foot device having a layer with laterally variable stiffness, the device comprising:

a) a foot member, configured to be coupled to an amputee, including an upper member having an attachment section configured to be coupled to a socket, and extending downwardly therefrom;

b) a heel member, disposed adjacent the foot member, including an upper member and extending downwardly and forwardly to a location corresponding to an approximate arch location of the user and rearwardly from the approximate arch location to an approximate heel location of the user;

c) a sole plate, disposed below the foot member, and having a heel section disposed at a natural location of a heel of a user and a toe section disposed at a natural location of a toe of the user; and

d) a layer with laterally variable stiffness, disposed above sole plate and having a medial portion, a lateral portion, and an intermediate portion between the medial and lateral portions;

e) the lateral portion and the medial portion having different stiffness; and

f) the intermediate portion having a greater stiffness than the medial and lateral portions.

2. A foot device in accordance with claim 1 , wherein the sole plate further includes an energy storing leaf spring.

3. A foot device in accordance with claim 1 , wherein the medial portion, the lateral portion and the intermediate portion extend longitudinally substantially an entire length of the foot plate.

4. A foot device in accordance with claim 1 , wherein the layer with laterally variable stiffness includes a urethane material extending across the medial portion, the lateral portion and the intermediate portion.

5. A foot device in accordance with claim 4 , wherein the urethane material of the intermediate portion has a greater durometer than the medial portion and the lateral portion, and wherein the lateral portion has a greater durometer than the medial portion.

6. A foot device in accordance with claim 1 , further comprising:

a secondary heel member disposed adjacent the heel member, including an upper member and extending downwardly therefrom to a location above the approximate heel location, the secondary heel member being engageable by the heel member at the approximate heel location to provide additional resistance to the heel member.

7. A prosthetic foot device having a layer with laterally variable stiffness, the device comprising:

a) a foot member, configured to be coupled to an amputee, including an upper member having an attachment section configured to be coupled to a socket, and extending downwardly and forwardly therefrom to an approximate toe location of a user;

b) a heel member, disposed adjacent the primary foot member, including an upper member extending downwardly and forwardly to a location corresponding to an approximate arch location of the user and rearwardly from the approximate arch location to an approximate heel location of the user;

c) a secondary heel member disposed adjacent the heel member, including an upper member and extending downwardly therefrom to a location above the approximate heel location, the secondary heel member being engageable by the heel member at the approximate heel location to provide additional resistance to the heel member; and

d) a sole plate, disposed below the foot member and the heel member, and having a heel section disposed at the approximate heel location of the user and a toe section disposed at the approximate toe location of the user; and

i) a layer with laterally variable stiffness, disposed above sole plate and having a medial portion, a lateral portion, and an intermediate portion between the medial and lateral portions;

ii) the lateral portion having a stiffness greater than the stiffness of the medial portion to provide a relatively softer instep and a relatively stiffer out-step; and

iii) the intermediate portion having a greater stiffness than the medial and lateral portions.

8. A foot device in accordance with claim 7 , wherein the sole plate further includes an energy storing leaf spring.

9. A foot device in accordance with claim 7 , wherein the medial portion, the lateral portion and the intermediate portion extend longitudinally substantially an entire length of the foot plate.

10. A foot device in accordance with claim 7 , wherein the layer with laterally variable stiffness includes a urethane material extending across the medial portion, the lateral portion and the intermediate portion.

11. A foot device in accordance with claim 10 , wherein the urethane material of the intermediate portion has a greater durometer than the medial portion and the lateral portion, and wherein the lateral portion has a greater durometer than the medial portion.

12. A foot device in accordance with claim 7 , wherein the lateral portion has a stiffness greater than a stiffness of the medial portion to provide a relatively softer instep and a relatively stiffer out-step.

13. A foot device in accordance with claim 7 , wherein the medial portion and the lateral portion extend longitudinally substantially an entire length of the foot plate.

14. A foot device in accordance with claim 7 , wherein the lateral portion and medial portion further include a forward section and a rearward section, and a stiffness of the forward section is different than a stiffness of the rearward section.

15. A foot device in accordance with claim 14 , wherein the forward section of the lateral portion has a greater stiffness than the rearward section of the lateral portion, and the rearward section of the medial portion has a greater stiffness than the forward section of the medial portion.

16. A foot device in accordance with claim 14 , wherein the rearward section of the lateral portion has a greater stiffness than the forward section of the lateral portion, and the forward section of the medial portion has a greater stiffness than the rearward section of the medial portion.

17. A foot device in accordance with claim 1 , wherein the lateral portion has a stiffness greater than a stiffness of the medial portion to provide a relatively softer instep and a relatively stiffer out-step.

18. A foot device in accordance with claim 1 , wherein the medial portion and the lateral portion extend longitudinally substantially an entire length of the foot plate.

19. A foot device in accordance with claim 1 , wherein the lateral portion and medial portion further include a forward section and a rearward section, and a stiffness of the forward section is different than a stiffness of the rearward section.

20. A foot device in accordance with claim 19 , wherein the forward section of the lateral portion has a greater stiffness than the rearward section of the lateral portion, and the rearward section of the medial portion has a greater stiffness than the forward section of the medial portion.

21. A foot device in accordance with claim 19 , wherein the rearward section of the lateral portion has a greater stiffness than the forward section of the lateral portion, and the forward section of the medial portion has a greater stiffness than the rearward section of the medial portion.