Prosthetic foot with tunable performance

• US 7,226,485 B2
• Filed: 10/04/2002
• Issued: 06/05/2007
• Est. Priority Date: 03/30/2001
• Status: Expired due to Fees

• Current Assignee: BioQuest Prosthetics LLC
• Original Assignee: BioQuest Prosthetics LLC
• Inventors: Townsend, Barry W., Claudino, Byron K.
• Primary Examiner(s): McDermott; Corrine
• Assistant Examiner(s): Blanco; Javier G.
• Application Number:
  US10/263,795
• Publication Number:
  US 20030028256A1
• Time in Patent Office: 1,705 Days
• Field of Search: 623/27, 623/38, 623/47, 623/48, 623/49, 623/50, 623/51, 623/52, 623/53
• US Class Current: 623/52
• CPC Class Codes: A61F 2/60 Artificial legs or feet or parts thereof
• CPC Class Codes: A61F 2/66 Feet; Ankle joints
• CPC Class Codes: A61F 2/6607 Ankle joints
• CPC Class Codes: A61F 2/74 fluid , i.e. hydraulic or pneumatic
• CPC Class Codes: A61F 2/76 Means for assembling, fitting or testing prostheses, e.g. for measuring or balancing, e.g. alignment means
• CPC Class Codes: A61F 2002/30433 using additional screws, bolts, dowels, rivets or washers e.g. connecting screws
• CPC Class Codes: A61F 2002/30462 retained or tied with a rope, string, thread, wire or cable
• CPC Class Codes: A61F 2002/5001 Cosmetic coverings
• CPC Class Codes: A61F 2002/5003 having damping means, e.g. shock absorbers
• CPC Class Codes: A61F 2002/5006 Dampers, e.g. hydraulic damper
• CPC Class Codes: A61F 2002/5007 having elastic means different from springs, e.g. including an elastomeric insert
• CPC Class Codes: A61F 2002/5009 having two or more elastomeric blocks
• CPC Class Codes: A61F 2002/503 for adjusting elasticity, flexibility, spring rate or mechanical tension
• CPC Class Codes: A61F 2002/5032 for adjusting fluid pressure
• CPC Class Codes: A61F 2002/5033 for adjusting damping
• CPC Class Codes: A61F 2002/5075 Multiple spring systems including two or more helical springs
• CPC Class Codes: A61F 2002/5079 Leaf springs A61F2002/6657 takes precedence
• CPC Class Codes: A61F 2002/5083 modular
• CPC Class Codes: A61F 2002/607 Lower legs
• CPC Class Codes: A61F 2002/6614 Feet
• CPC Class Codes: A61F 2002/6621 : Toes
• CPC Class Codes: A61F 2002/6628 : Big toes
• CPC Class Codes: A61F 2002/6635 : Metatarsals
• CPC Class Codes: A61F 2002/6642 : Heels
• CPC Class Codes: A61F 2002/665 : Soles
• CPC Class Codes: A61F 2002/6657 : having a plate-like or strip-like spring element, e.g. an energy-storing cantilever spring keel
• CPC Class Codes: A61F 2002/6664 : Dual structures made of two connected cantilevered leaf springs
• CPC Class Codes: A61F 2002/6671 : C-shaped
• CPC Class Codes: A61F 2002/6678 : L-shaped
• CPC Class Codes: A61F 2002/6685 : S-shaped
• CPC Class Codes: A61F 2002/704 : computer-controlled, e.g. robotic control
• CPC Class Codes: A61F 2002/7615 : Measuring means
• CPC Class Codes: A61F 2220/0041 : using additional screws, bolts, dowels or rivets, e.g. connecting screws
• CPC Class Codes: A61F 2220/0075 : sutured, ligatured or stitched, retained or tied with a rope, string, thread, wire or cable
• CPC Class Codes: A61K 9/4816 : Wall or shell material

Abstract

A prosthetic foot incorporate a foot keel and a calf shank connected to the foot keel to form an ankle joint area of the prosthetic foot. The foot keel has forefoot and hindfoot portions and a relatively long midfoot portion extending between and upwardly arched from the forefoot and midfoot portions. The calf shank includes a downward convexly curved lower end which is attached at a portion thereof to the keel midfoot portion by way of an adjustable fastener arrangement. The foot has biplanar motion capability and, in a preferred form, also has high low dynamic response characteristics. The adjustable fastener arrangement permits adjustment of the alignment of the calf shank and the foot keel with respect to one another in the longitudinal direction of the foot keel for tuning the performance of the prosthetic foot.

Claims

1. A prosthetic foot comprising:

a longitudinally extending;

resilient foot keel;

a resilient, monolithically formed shank with a lower portion forming an ankle joint area of the prosthetic foot, a middle portion, and a proximal portion with a straight upper end for connection to a supporting structure on a person'"'"'s residual leg, said lower portion including a downward facing convexly curved resilient surface posteriorly terminating in a free end of the shank and anteriorly extending upwardly to said middle portion by way of an anterior facing continuous convexly curved surface with increasing radius of curvature, said shank being compressible and expandable in the longitudinal direction of the foot keel during gait to simulate human ankle joint plantarflexion and dorsiflexion;

a fastening arrangement, including a coupling element and at least one fastener, connecting and securely positioning the lower portion of the shank to a midfoot portion of the foot keel for creating a dynamic response capability and motion outcome of the foot in gait.

2. The prosthetic foot according to claim 1, wherein the shank is anterior facing convexly curved from the foot keel to the straight upper end.

3. The prosthetic foot according to claim 1, wherein the shank is J-shaped.

4. The prosthetic foot according to claim 1, wherein the shank below the straight upper end is in the shape of a parabola.

5. The prosthetic foot according to claim 1, wherein said fastening arrangement includes a longitudinally extending opening in the lower portion of the shank to permit adjustment of the alignment of the shank and foot keel with respect to one another in the longitudinal direction of the foot keel.

6. The prosthetic foot according to claim 1, wherein said fastening arrangement includes means for adjusting the inclination at which the shank is coupled to the foot keel in the longitudinal direction of the foot keel.

7. The prosthetic foot according to claim 1, wherein the foot keel is formed with a longitudinal arch whose medial aspect has a relatively higher dynamic response capability than its lateral aspect to provide the prosthetic foot with a high low dynamic response capability in gait.

8. The prosthetic foot according to claim 1, wherein the foot keel includes posterior and anterior plantar surface weight bearing areas and a non-weight bearing midportion extending between the weight bearing areas.

9. The prosthetic foot according to claim 8, wherein the anterior plantar surface weight bearing area of the foot keel includes laterally spaced expansion struts which create biplanar motion capability of the foot keel.

10. The prosthetic foot according to claim 8, wherein the anterior plantar surface weight bearing area of the foot keel is oriented at an angle to the longitudinal axis of the foot keel with its medial side more anterior than its lateral.

11. The prosthetic foot according to claim 10, wherein the anterior plantar surface weight bearing area of the foot keel is oriented at an angle of 20°

to 35°

to the longitudinal axis of the foot keel.

12. The prosthetic foot according to claim 8, wherein the portion of the foot keel including the anterior plantar surface weight bearing area is upward concavely curved.

13. The prosthetic foot according to claim 8, wherein the foot keel includes a pad on the posterior plantar surface weight bearing area thereof.

14. The prosthetic foot according to claim 1, further comprising an adapter connected to the proximal portion of the shank for use in connecting the prosthetic foot to a supporting structure on a person'"'"'s residual leg.

15. The prosthetic foot according to claim 1, wherein said shank below the straight upper end is S-shaped.

16. The prosthetic foot according to claim 1, wherein the shank is C-shaped.

17. The prosthetic foot according to claim 1, wherein the foot keel is formed of a single piece of resilient material.

18. A prosthetic foot comprising:

a longitudinally extending, resilient foot keel;

a single, resilient, monolithically formed shank with a lower portion forming an ankle joint area of the prosthetic foot, a middle portion, and a proximal portion for connection to a supporting structure on a person'"'"'s residual leg, said lower portion posteriorly terminating in a free end of the shank and anteriorly extending upwardly to said middle portion by way of an anterior facing continuous convexly curved surface with an increasing radius of curvature such that said ankle joint area of the prosthetic foot has dorsiflexion and plantarflexion motion capabilities in response to ground reaction force in gait in the prosthetic foot;

wherein both the ankle joint area and a prosthetic part of a leg formed by the shank above the ankle joint area are compressible and expandable in the longitudinal direction in response to the ground reaction force thereon during gait with the upper end of the shank moving posteriorly in plantarflexion and moving anteriorly in dorsiflexion for storing and releasing energy to improve dynamic response of the prosthetic foot in gait;

a fastening arrangement, including at least one fastener, connecting and securely positioning the lower portion of the shank to the foot keel for creating a dynamic response capability and motion outcome of the foot in gait;

wherein the shank solely bears and transfers the body weight bearing force created on the prosthetic foot in said gait to oppose the ground reaction force created in the prosthetic foot in said gait.

19. The prosthetic foot according to claim 18, wherein the ankle joint area and the prosthetic part of a leg formed by the shank above the ankle joint area are anterior facing convexly curved.

20. The prosthetic foot according to claim 19, wherein the convexly curved ankle joint area has a relatively smaller radius of curvature than the prosthetic part of a leg formed by the shank above the ankle joint area.

21. The prosthetic foot according to claim 18, wherein said shank is J-shaped.

22. The prosthetic foot according to claim 18, wherein the shank is in the shape of parabola.

23. The prosthetic foot according to claim 18, wherein said fastening arrangement includes a longitudinally extending opening in the lower portion of the shank to permit adjustment of the alignment of the shank and foot keel with respect to one another in the longitudinal direction of the foot keel.

24. The prosthetic foot according to claim 18, wherein said fastening arrangement includes means for adjusting the inclination at which the shank is connected to the foot keel in the longitudinal direction of the foot keel.

25. The prosthetic foot according to claim 18, wherein said shank is S-shaped.

26. The prosthetic foot according to claim 18, wherein the shank is C-shaped.

27. The prosthetic foot according to claim 18, wherein the foot keel is formed with a longitudinal arch whose medial aspect has a relatively higher dynamic response capability than its lateral aspect to provide the prosthetic foot with a high low dynamic response capability in gait.

28. The prosthetic foot according to claim 18, wherein the shank extends upward in a substantially curvilinear manner that is reversely curved at an upper end of the shank to merge with a straight upper end of the shank.

29. The prosthetic foot according to claim 18, further comprising an adapter connected to the proximal portion of the shank for use in connecting the prosthetic foot to a supporting structure on a person'"'"'s leg stump.

30. The prosthetic foot according to claim 18, wherein the foot keel includes a pad on a posterior plantar surface weight bearing area thereof.

31. The prosthetic foot according to claim 18, wherein an anterior plantar surface weight bearing area of the foot keel includes laterally spaced expansion struts which create biplanar motion capability of the foot keel.

32. The prosthetic foot according to claim 18, wherein the foot keel includes posterior and anterior plantar surface weight bearing areas and a non-weight bearing midportion extending between the weight bearing areas.

33. The prosthetic foot according to claim 32, wherein the anterior plantar surface weight bearing area of the foot keel includes laterally spaced expansion struts which create biplanar motion capability of the foot keel.

34. The prosthetic foot according to claim 32, wherein the anterior plantar surface weight bearing area of the foot keel is oriented at an angle to the longitudinal axis of the foot keel with its medial side more anterior than its lateral.

35. The prosthetic foot according to claim 34, wherein the anterior plantar surface weight bearing area of the foot keel is oriented at an angle of 20°

to 35°

0 to the longitudinal axis of the foot keel.

36. The prosthetic foot according to claim 32, wherein the portion of the foot keel including the anterior plantar surface weight bearing area is upward concavely curved.

37. The prosthetic foot according to claim 32, wherein the foot keel includes a pad on the posterior plantar surface weight bearing area thereof.

38. The prosthetic foot according to claim 18, further comprising an adapter connected to the proximal portion of the shank for use in connecting the prosthetic foot to a supporting structure on a person'"'"'s residual leg.

39. The prosthetic foot according to claim 18, wherein the shank is C-shaped.

40. The prosthetic foot according to claim 18, wherein the foot keel is formed of a single piece of resilient material.

41. A method of improving a dynamic response of a prosthetic foot in gait, comprising:

providing a prosthetic foot including a longitudinally extending, resilient foot keel having forefoot, midfoot and hindfoot portions, and a resilient, upstanding, elongated, monolithically formed shank with a lower portion forming an ankle joint area of the prosthetic foot, a middle portion, and a proximal portion for connecting to a supporting structure on a person'"'"'s residual leg, said lower portion posteriorly terminating in a free end of the shank, and anteriorly extending upwardly to said middle portion by way of an anterior facing continuous convexly curved surface with increasing radius of curvature, said shank being compressible and expandable in the longitudinal direction of the foot keel during gait to simulate human ankle joint plantarfiexion and dorsiflexion, a fastening arrangement, including a coupling element and at least one fastener, connecting and securely positioning the lower portion of the shank to the foot keel, and said shank having a substantially curvilinear portion above the ankle joint area, the upper end of the shank moving in the longitudinal direction posteriorly in plantarflexion and anteriorly in dorsiflexion, and said shank having a width in the frontal plane which is greater than the thickness of the shank in the sagittal plane throughout the entire length of the shank such that the member, in response to a ground reaction force created in the prosthetic foot in gait, flexes substantially in the longitudinal direction of the prosthetic foot for storing, releasing and directing energy in a longitudinal direction to improve dynamic response of the prosthetic foot;

storing and releasing energy with said portions of the resilient elongated shank in response to ground reaction force thereon during gait to improve dynamic response of the prosthetic foot, wherein the shank solely bears and transfers the body weight bearing force created on the prosthetic foot in said gait to oppose said ground reaction force.

43. The method of claim 41, wherein said curved portion of the shank above the ankle joint area has a relatively larger radius of curvature than the curved lower portion of the shank for increased dynamic response capability.

42. The method of clam 41, wherein said curved portion above the ankle joint area is anterior facing convexly curved.

44. A prosthetic foot comprising:

a longitudinally extending, resilient foot keel having forefoot, midfoot and hindfoot portions;

a single, resilient, upstanding, elongated, monolithically formed shank with a lower portion forming an ankle joint area of the prosthetic foot, a middle portion, and a proximal portion for connection to a supporting structure on a person'"'"'s residual leg, said lower portion posteriorly terminating in a free end of the shank and anteriorly extending upwardly to said middle portion by way of an anterior facing continuous convexly curved surface with an increasing radius of curvature, said shank being compressible and expandable in the longitudinal direction of the foot keel during gait to simulate human ankle joint plantarflexion and dorsiflexion;

wherein the shank extends upward in a substantially curvilinear manner above the ankle joint area to form a lower, prosthetic part of a leg above the ankle joint area;

a fastening arrangement, including at least one fastener, connecting and securely positioning the lower portion of the shank to the foot keel for creating a dynamic response capability and motion outcome of the foot in gait;

wherein the shank solely bears and transfers the body weight bearing force created on the prosthetic foot in said gait to oppose the ground reaction force created in the prosthetic foot in said gait.

45. The prosthetic foot according to claim 44, wherein the shank forming the lower, prosthetic part of a leg extends upward in a substantially curvilinear manner that is reversely curved to merge with a straight upper end of the shank.

46. The prosthetic foot according to claim 44, further comprising an adapter connected to an upper end of the shank for use in connecting the prosthetic foot to a supporting structure on a person'"'"'s residual leg.

47. The prosthetic foot according to claim 44, wherein the foot keel has an anterior plantar surface weight bearing area that includes laterally spaced expansion struts which create biplanar motion capability of the foot keel.

48. The prosthetic foot according to claim 44, wherein the foot keel is formed of a single piece of resilient material.

49. A prosthesis comprising:

a longitudinally extending, resilient foot;

an ankle;

a single, elongated, upstanding shank above the ankle;

wherein the ankle and shank are monolithically formed as a resilient member for improving the dynamic response of the prosthesis, the ankle posteriorly terminating in a free end of the member and anteriorly extending upwardly to said shank by way of an anterior facing continuous convexly curved surface with an increasing radius of curvature, said member being compressible and expandable in the longitudinal direction of the foot during gait to simulate human ankle joint plantarflexion and dorsiflexion and said shank solely bearing and transferring the body weight bearing force created on the prosthesis in said gait to oppose the ground reaction force created in the prosthesis in said gait;

a fastening arrangement, including at least one fastener, connecting and securely positioning the ankle of the member to the foot for creating a dynamic response and motion outcome of the foot in gait.

50. The prosthesis according to claim 49, wherein the shank is curved in the direction of the longitudinal extent of the foot.

51. The prosthesis according to claim 50, wherein the shank has a straight upper end.

52. The prosthesis according to claim 49, wherein the shank has a straight upper end.

53. The prosthesis according to claim 49, wherein the foot includes a foot keel.

54. The prosthesis according to claim 53, wherein the foot keel is formed of a single piece of resilient material.

55. The prosthesis according to claim 49,

wherein said member having a width in the frontal plane which is greater than the thickness of the member in the sagittal plane throughout the entire length of the member such that the member flexes in the longitudinal direction of the foot during gait for storing and releasing energy to improve dynamic response of the prosthesis in gait.

56. The prosthesis according to claim 55, wherein said resilient member has a generally rectangular shape.