Presentation on prosthetic foot

This presentation is very beneficial for those who are in the field of prosthetics & orthotics. I have covered the basics of prosthetic foot, its mechanisms & its types. I have mentioned advanced prosthetic foot also. Hope this will help you all.

1. PRESENTATION ON PROSTHETIC FOOT By Aamir Siddiqui

2. CONTENTS

3. INTRODUCTION Current prosthetic foot designs do not replicate the exact characteristics of a normal foot. A human foot is a multi-functional device that can be used to perform a wide range of activities, however a prosthetic foot is limited to only a few. More recently, manufacturers of prosthetic feet have looked into the characteristics of a prosthesis that may be adjustable. The amputee may then able to perform number of activities without requiring a different prosthesis. Prosthetic foot provide essential connection between prosthesis and ground Currently divided into traditional foot classifications: SACH FLEXIBLE KEEL SINGLE AXIS MULTI AXIS DYNAMIC RESPONSE

4. PURPOSE OF PROSTHETIC FOOT The purpose of prosthetic foot is to serve in place of anatomical foot in terms of cosmesis and functions. Cosmesis : prosthetic foot looks like an anatomical foot. Functions like walking , balancing etc.

5. FUNCTIONS OF PROSTHETIC FOOT Joint simulation : By helping in dorsiflexion & plantarflexion By helping in inversion & eversion Smooth roll over during heel off & toe off. All these movements of prosthetic foot simulates the anatomical foot and thus provides us smooth, more natural and low energy expenditure gait pattern. Shock Absorption: - The foot must absorb the impact of heel strike and weight acceptance without transmitting excessive forces to the residual limb. Too much shock absorption, in contrast, might fail to generate the normal knee flexion when the foot is flat and result in an unacceptable gait pattern. moment A stable weight-bearing base of support Muscle simulation Cosmesis : While function of the prosthetic foot is of primary concern to the prosthetist, the importance of cosmesis cannot be overlooked. The design of a particular foot may enhance or diminish its cosmetic appeal.

6. CLASSIFICATION OF PROSTHETIC FOOT

7. JAIPUR FOOT The  Jaipur Foot , also known as the  Jaipur Leg. It is a rubber-based  prosthetic leg  for people with below-knee  amputations . Although inferior in many ways to the composite carbon fibre variants, its variable applicability and cost efficiency make it an acceptable choice for prosthesis. Ram Chander Sharma designed and developed it in 1968 It is a foot piece of same contour (shape) as a human foot with fingers. It can be used without shoes for base foot walking. Mostly used by people who belongs to rural background. It has wide range of motion such as plantarflexion, dorsiflexion, inversion & eversion helps in cross legged position.

8. MATERIAL REQUIRED FOR JAIPUR FOOT Ordinary MCR ( Micro Cellular Rubber ), Rubber Cord, Rubber Cushion, Skin Coloured Rubber, Dyes, and Stationary ankle

9. ADVANTAGES OF JAIPUR FOOT It doesn’t require shoes & has certain degree of cosmetic acceptance by amputee. It permits certain degree of transverse rotation to facilitate gait Easily available and cheap. Made up of waterproof material. Raw materials used for making Jaipur Foot is easily available. In appearance, it mimics a real foot.

10. SACH FOOT It was first manufactured by University of California in 1947. SACH stands for Solid-Ankle Cushion-Heel Feet. Introduced in 1956 by Radcliffe and Foort . The light weight, durability, low cost, and cosmesis of the SACH foot make it the single most frequently recommended prosthetic foot. Although recent innovations in prosthetic foot design may change this, the SACH foot has been the traditional foot of choice for children and for the majority of adult patients with transtibial or ankle disarticulation amputations. They are available for multiple shoe styles and heel heights, postoperative uses, Syme's fittings, external-keel "waterproof' fittings, and pediatric sizes. The cushioned heel compressed under loading to stimulate ankle plantarflexion and the eccentric contraction of the ankle dorsiflexors during loading response.

11. ADVANTAGES & DISADVANTAGES OF SACH FOOT ADVANTAGES Smooth, Durable, Light Weight, Requires little maintenance, Higher degree of acceptance by amputee, and Psychologically accepted by women & children , Good shock absorption for moderately active patients. DISADVANTAGES Lack of ability to absorb the torque produced during locomotion, Limited range of plantarflexion, The heel cushion deteriorates over time, The heel cushion may loose elasticity, The rigid forefoot provides poor shock absorption for high-output activities.

12. TYPES OF SACH FOOT

13. STANDARD SACH FEET Also known as Internel -Keel Sach Foot. Internal-keel SACH feet include a solid wood or aluminum internal keel that extends to the toe break and is surrounded by a molded external foam foot with cosmetic toes and a cushioned heel wedge available in different densities.

14. POSTOPERATIVE SACH FOOT The postoperative SACH foot is designed so that the patient can walk without shoes or in slippers. As the name implies, its primary use is on postoperative or temporary prostheses. It has no heel rise, and since no shoes are worn, the postoperative foot has a wider sole than a standard SACH foot to provide more stability. The molded rubber foot and heel are softer, which makes the postoperative foot very shock absorbent.

15. SYME SACH FOOT The Syme SACH foot was designed to provide the ankle disarticulation amputee with the advantages of a SACH foot. Since an ankle disarticulation in an adult results in only an average I½ in. shortening of the leg, the space available for the addition of a prosthetic foot is limited. The Syme foot, therefore, is lower in height than the SACH foot in order to accommodate this minimal ground clearance. Important to note is the thinner heel cushion. Because the foot height is reduced, the heel cushion is also reduced and therefore less shock absorbent.

16. EXTERNAL-KEEL SACH FOOT In the external-keel SACH foot the keel portion is not incorporated within the rubber foot. Instead, the rubber portion of the foot is affixed to the keel. It is used for exoskeletal prostheses only. This foot is recommended for a Syme prosthesis when an internal-keel foot will not accommodate a minimal leg length discrepancy. The need for optimum cosmesis at the ankle on an exoskeletal prosthesis may also be an indication for an external-keel SACH foot. The foot's wider keel makes it ideal for patients who require added stability, although an attempt should be made to gain stability through prosthetic alignment first. The external-keel SACH foot also permits the prosthesis to be made waterproof.

17. JAIPUR FOOT V/S SACH FOOT SACH FOOT On the basis of appearance SACH foot doesn’t look like a normal foot. SACH foot requires a closed shoe to protect as well as hide it. JAIPUR FOOT On the basis of appearance It looks like a normal foot No such need or requirement with Jaipur Foot. But in case someone wants to wear a shoe, he can do it comfortably with a flat heel shoe.

18. JAIPUR FOOT V/S SACH FOOT JAIPUR FOOT On the basis of Movements & ADL Cross- legged sitting is possible because sufficient forefoot adduction & transverse rotation of foot in relation to shank is available. Squatting is easily achieved. Bare-Foot walking is possible. As transverse rotation of foot in relation to leg is possible, no complaint of discomfort while walking on uneven ground. SACH FOOT On the basis of Movements & ADL No cross-leg sitting is possible because it requires adduction at forefoot & transverse rotation of foot in relation to shank. Squatting is not possible. Bare-Foot walking is not possible Great discomfort is complained by amputees while walking on uneven surface.

19. STEN FOOT The STEN foot is one of the simplest designs in prosthetic feet for it uses the Kingsley foot moulds and rubbers. It comes in a wide variety of sizes and heel heights from a child (18cm keel) through to an adult (30cm keel). The heels also come is soft, medium or hard densities. Although it is slightly heavier than the conventional SACH foot, it differs in its keel which allows for smooth roll - over of the prosthesis. As the name suggests the STEN, STored ENergy , has the capacity to store energy. However, the effectiveness of its ability to store energy is debatable. The structure of its keel disperses the energy rather than storing and then returning it. The STEN Foot is characterised by its : Varying density heel Polyurethane bumpers Reinforcement bands

20. ADVANTAGES & DISADVANTAGES OF STEN FOOT

21. SAFE FOOT SAFE stands for STATIONARY ATTACHMENT FLEXIBLE ENDOSKELETAL foot. The SAFE Foot (Stationary Ankle Flexible Endoskeleton) has a solid ankle and provides large amounts of transverse rotation as well as inversion and eversion. The advantage of the SAFE Foot is that it is moisture and grit - resistant. This makes this prosthesis very low maintenance The SAFE foot and other soft keel designs should be viewed as offering increased shock absorption and comfort at the expense of responsiveness in a competitive situation.

22. ADVANTAGES & DISADVANTAGES OF SAFE FOOT

23. CONEVNTIONAL OR MECHANICAL FOOT Conventional foot is of three types : Single-Axis Foot Double-Axis Foot Multi-Axis Foot

24. SINGLE-AXIS FOOT The single-axis foot is available for exoskeletal or endoskeletal prostheses. Its components include a solid wood internal keel, a molded foam rubber shell, a metal single-axis joint, a rubber plantar flexion bumper, and a dorsiflexion stop. Ankle plantar flexion and dorsiflexion are provided in a limited way by rotation about the ankle joint. Minimal inversion and eversion occur through the flexibility of the rubber sole. Toe dorsiflexion is simulated by the flexibility of the rubber toe section.

25. SINGLE-AXIS FOOT The single-axis foot offers shock absorption at heel strike through the plantar flexion bumper, which is available in multiple durometers. Because the foot plantar-flexes after heel strike, thus dampening knee flexion moments, and since it is in contact with the ground for a longer period of time, stance-phase stability is excellent. Single-axis feet have specific application in transfem -oral (above-knee) prosthetics and are rarely necessary for transtibial amputees, although some amputees prefer the sensation of ankle motion.

26. ADVANTAGES & DISADVANTAGES OF SINGLE-AXIS FOOT ADVANTAGES The plantar flexion capability provides increased knee stability at heel strike and foot flat and may lessen the difficulty of descending inclines. Plantar flexion resistance can be varied DISADVANTAGES Relatively high maintenance due to moving components. Increased weight. Less cosmetic. Tendency to "squeak."

27. DOUBLE- AXIS FOOT Also known as Foreway Foot. It has medio-lateral ankle joints. Provides plantarflexion, dorsiflexion, inversion and eversion It is heavier than Single-Axis Foot It has two rubber bumper which are added medially and laterally to provide inversion and eversion. It is not commonly used.

28. MULTI-AXIS FOOT This foot provides more ankle motion than any other prosthetic foot. Available for endoskeletal and exoskeletal prostheses, it provides motion in all three planes, which makes it particularly suitable for patients who walk on uneven terrain. Its components include a solid-wood internal keel, a molded rubber foot, a central rubber rocker block that allows sagittal-plane motion, and a transverse ankle joint that provides inversion, eversion, and transverse rotation. Joint simulation is achieved by the various bumpers. Although transverse rotation is not truly an anatomic ankle joint motion, it reduces shear forces transmitted to the residual limb and is an alternative to a rotation unit.

29. MULTI-AXIS FOOT Shock absorption is excellent in the multiaxis foot because of the many bumpers. The degree of compressibility and rebound of these individual components determines the degree of shock absorption during various gait phases. Because of the many motions it allows, the foot may be considered less stable statically. However, because of its ability to absorb forces in all planes the multiaxis foot reduces torque on the residual limb that might occur on uneven terrain. It is a good option for patients who traverse frequently over uneven terrain, but its increased weight and maintenance may overshadow its advantages. It is not recommended for patients who are weak and debilitated, those for which cosmesis is a priority, or those with limited access to prosthetic follow-up.

30. ADVANTAGES & DISADVANTAGES OF MULTI-AXIS FOOT ADVANTAGES Allows motion in all planes. Reduces torque on the residual limb. Adjustability. DISADVANTAGES Increased weight. Increased maintenance. Decreased cosmesis . May provide less stability than other feet on smooth surfaces

31.   GREISSINGER FOOT The Greissinger Foot is a multi-axial foot that allows for rotation in all three phases : Flexion / extension Inversion / eversion Internal / external rotation Multi - axis foot - ankle assemblies such as the Greissinger Foot were designed for very active below - knee amputees. They are widely used to reduce the shearing action between the stump and the socket. The Greissinger Foot is characterised by its : Carbon fibre keel Polyurethane casing Multi - axis ankle The advantage of having a multiple degree of freedom axis is that it allows for inversion / eversion that enables the patient to walk on uneven ground.

32. FLEXIBLE-KEEL DYNAMIC RESPONSE FOOT

33. FLEXIBLE-KEEL DYNAMIC RESPONSE FOOT

34. SPRINGLITE FOOT It is similar in design to the flex foot It consists of carbon & fibre glass filaments surrounded by a short cover.

35. NON-ARTICULATED SHORT KEEL FEET A non-articulated short-keel design dynamic response foot doesn’t attach to the socket but is attached to a pilon at the ankle. Since, they have shortened keel, they are less responsive and provides less dorsiflexion than the long keel design. Examples : SEATTLE FOOT CC II ( CARBON COPY II ) FOOT QUANTUM FOOT

36. SEATTLE FOOT It is a Non-Articulated Short-keel foot. It was developed in early 1980s at the University of Washington. This was the first foot to provide increased push-off. It was initially developed for runners and has leaf like appearance and a cleft between great and second-tea that allows bearing beach things. During mid to terminal stance, the keel section gradually stores energy, i.e., released at the end of stance-off.

37. ADVANTAGES & DISADVANTAGES OF SEATTLE FOOT

38. CARBON COPY II FOOT

39. FIGURE SHOWING CC II FOOT

40. CARBON COPY II FOOT

41. ADVANTAGES & DISADVANTAGES OF CC II FOOT

42. FIGURE SHOWING SEATTLE, DYNAMIC, STEN, SAFE & CC II FOOT

43. QUANTUM FOOT The Quantum, foot was designed and manufactured by Hanger in London and consists of three major components : The spring module The foam ankle cosmesis The foot cosmesis The Quantum foot offers a good range of eversion and inversion as well as rotational control, enabling the patient to walk on inclined surfaces. The foam ankle cosmesis is manufactured from its block form to its desired shape and attached to the foot. The foot cosmesis is a rubber cover for the spring module. Features such as toes and skin colour give it good cosmetic properties.

44. ARTICULATED DYNAMIC RESPONSE FOOT

45. TRU STEP FOOT Made by the company, named “ College Park”. It was designed to mimic the anatomical foot and ankle. This foot contains cushioning bumpers and ankle alignment bushings. ADVANTAGES Increased stability & adjustable bumpers. DISADVANTAGES Increased maintenance, Expensive, Available only for adult sizes, low heeled shoes.

46. ADVANCED PROSTHETIC FOOT PROPRIO FOOT It is also known as Intelligent foot. Manufactured by the company of USA, “ OSSUR “. It provides unprecedented psychological benefits for transtibial amputee. A wide & automated range of ankle fraction with proven flex-foot dynamics means functions as close as you can get today to the human foot. Has stress & strain sensors to determine the scenario of surrounding and receive stimulation.

47. PROPRIO FOOT This foot “ thinks for itself “ responding beautifully to changing terrain & transforming the approach to stairs and slopes, as well as level ground walking angling itself approximately. Also helps amputees to sit and stand up easily and more naturally Heel height can be changed easily with no impact on alignment of prosthesis. Overall, the effect is a feeling of improved proprioception with more balanced, symmetric and a confident gait with reduced wear & tear on the back, hips and knees. Cutting edge sensors technology & artificial intelligence identifies sloping gradients and ascent & descent of stairs, after the first step and instructs the ankle to flex properly.

48. PROPRIO FOOT Users can place the foot fully on a step when climbing, descending stairs and it will automatically adopt it’s ankle position to enable the next stop. The active ankle motion also allows users to tuck both feet back behind their knees when getting up from chair or sitting down. Also points the toe down for a more natural appearance once seated, when walking it automatically gives the toe a lift at exact point. In swing phase, that will allow sufficient ground clearance to prevent dragging of foot. Despite it’s sophisticated technology, the proprio foot has an extremely user friendly design and is easy to set up and operate.

49. BATTERY OF PROPRIO FOOT Simple di-ion battery facilitates 36 hrs of constant use. CHARGING TIME : 3-4 Hrs with 90% discharge at home / on the road. TURN-OFF POWER : When not in use to extend power.

50. CONCLUSION

51. THANK YOU