Adjustable stiffness prosthetic foot

A prosthetic foot, comprising:

• a top leaf spring;
• a bottom leaf spring spaced apart from and positioned vertically below the top leaf spring and arranged in parallel with the top leaf spring along an entire length of the top leaf spring;
• a stiffness adjustment member affixed to one of the top and bottom leaf springs and adjustable along a length of the prosthetic foot to adjust a stiffness of the prosthetic foot;
• a position fixing feature formed on one of the top and bottom leaf springs, wherein the position fixing feature comprises a plurality of positioning grooves that are configured to fix the stiffness adjustment member at a location along the length of the top and bottom leaf springs, wherein the plurality of positioning grooves are formed on a surface of one of the top and bottom leaf springs, and wherein the plurality of positioning grooves extend across the surface of one of the top and bottom leaf springs;
• and
• a prosthetic attachment member mounted to the top leaf spring;
• wherein the top leaf spring and the bottom leaf spring are fixed to each other at a heel end of the prosthetic foot and disconnected from each other at a toe end of the prosthetic foot.

A prosthetic foot, comprising:

• a spring assembly, comprising:
• a first leaf spring;
• a second leaf spring spaced apart from and positioned vertically below the first leaf spring and arranged in parallel with the first leaf spring along an entire length of the first leaf spring and the second leaf spring;
• a heel end portion;
• a toe end portion;
• a spacer positioned between the first leaf spring and second leaf spring at the heel end portion;
• a stiffness adjustment member positioned at the toe end portion and adjustable along a length dimension of the prosthetic foot to adjust a stiffness of the prosthetic foot;
• a position fixing feature formed on one of the first and second leaf springs, wherein the position fixing feature comprises a plurality of positioning grooves that are configured to fix the stiffness adjustment member at a location along the length of the first and second leaf springs, wherein the plurality of positioning grooves are formed on a surface of one of the first and second leaf springs, and wherein the plurality of positioning grooves extend across the surface of one of the first and second leaf springs,
• wherein the first leaf spring and the second leaf spring are fixed to each other at the heel end portion and disconnected from each other at the toe end portion;
• a prosthetic attachment member positioned vertically above the first leaf spring;
• and
• a heel member positioned vertically below the second leaf spring.

A method of adjusting a stiffness of a foot prosthesis, the method comprising:

• providing at least first and second leaf springs spaced apart and arranged in parallel with each other along an entire length of the first leaf spring and the second leaf spring, a stiffness adjustment device, a prosthetic attachment member, and a heel member, wherein a positioning fixing feature comprising a plurality of positioning grooves formed on one of the first and second leaf springs, wherein the plurality of positioning grooves are formed on a surface of one of the first and second leaf springs, and wherein the plurality of positioning grooves extend across the surface of one of the first and second leaf springs;
• mounting the prosthetic attachment member to the first leaf spring, the prosthetic attachment member being configured to connect the foot prosthesis to a lower limb prosthesis;
• mounting the heel member to the second leaf spring, the heel member arranged to contact a ground surface at a heel area of the foot prosthesis;
• affixing the stiffness adjustment device to at least one of the first and seond leaf springs;
• and
• adjusting a position of the stiffness adjustment device relative to at least one of the first and second leaf springs to adjust a stiffness of the foot prosthesis, wherein the positioning fixing feature holds the stiffness adjustment device in an adjusted position along a length of the foot prosthesis.