Prosthetic feet having heel height adjustability
Prosthetic feet that allow for heel height adjustment and/or provide metatarsal joint functionality to more closely mimic natural human feet are provided. A prosthetic foot can include an ankle module having a locking mechanism configured to lock the heel at a particular height. The prosthetic foot can also include a toe region that adapts to varying heel heights. The ankle module and/or locking mechanism can be adjusted, controlled, and/or locked via a hydraulic mechanism. The toe region can curve upward relative to a portion of the foot proximal of the toe region.
1. A prosthetic foot comprising:
an elongate foot member extending from a proximal end to a distal end; and
an elongate lower foot member extending from a proximal end to a distal end, wherein the lower foot member is positioned below and coupled to the foot member and the lower foot member extends distally beyond the distal end of the foot member to form a toe region; and
an ankle module coupled to the proximal end of the foot member and configured to be coupled to a lower limb member, the ankle module comprising:
first and second pistons;
a central cavity between the first and second pistons;
a hydraulic fluid in the central cavity;
an intermediate wall separating the central cavity into first and second cylinders;
a spool valve extending through the intermediate wall, the spool valve actuatable to selectively place the first and second cylinders in fluid communication; and
a ball lock actuatable to selectively place the valve in an open or closed position, the ball lock comprising a first end portion, one or more balls, and at least one spring;
wherein the ankle module is selectively actuatable to adjust an angle between the prosthetic foot and the lower limb member to allow for adjustment of a heel height of the prosthetic foot.
2. The prosthetic foot of claim 1 , the ball lock further comprising a second end portion disposed opposite the first end portion along the spool valve, at least one button spring, and a wire attached to the second end portion, wherein when a user pulls the wire in use, the wire causes movement of the second end portion, thereby shifting the spool valve to the open position and compressing the at least one button spring.
3. The prosthetic foot of claim 2 , the ball lock further comprising a secondary wire attached to the first end portion, wherein when a user pulls the secondary wire in use, the secondary wire causes movement of the first end portion, thereby shifting the spool valve to the closed position.
4. The prosthetic foot of claim 1 , further comprising a washer coupled to a lower surface of at least one of the first and second pistons, the washer having a downward-facing convex bottom surface, and a piston base coupled to a base portion of the ankle module, the piston base having an upward-facing concave upper surface, wherein the upward-facing concave upper surface of the piston base is configured to pivotably receive the downward-facing convex bottom surface of the washer to accommodate changes in an angle between the at least one of the first and second pistons and the base portion.
5. The prosthetic foot of claim 1 , wherein the toe region curves upward and is configured to adapt to various heel heights of the prosthetic foot.
6. The prosthetic foot of claim 1 , wherein the toe region comprises glass fiber.
7. The prosthetic foot of claim 1 , wherein the lower foot member comprises one or more layers of glass fiber extending from the proximal end to the distal end and one or more layers of carbon fiber extending from the proximal end to a point proximal of the distal end.
8. The prosthetic foot of claim 1 , further comprising an upper foot member extending from a proximal end to a distal end, the upper foot member positioned above the foot member and the proximal end coupled to the proximal end of the foot member and the ankle module.
9. The prosthetic foot of claim 8 , wherein the distal end of the upper foot member is separated from the foot member by a gap when the prosthetic foot is at rest in a neutral position.
10. The prosthetic foot of claim 1 , wherein the toe region comprises a generally U-shaped cut-out extending proximally from the distal end of the lower foot member, the lower foot member comprises a split extending at least partially along a longitudinal axis of the lower foot member to the cut-out, and a transition between the split and the cut-out is rounded.