Prosthetics PMR Refresher Course

1. ProstheticsProsthetics

2. Dr. Anil Kumar JainDr. Anil Kumar Jain
M.D. DNB MNAMSM.D. DNB MNAMS
Physical Medicine & RehabilitationPhysical Medicine & Rehabilitation
Dr. P.K. Sethi Rehabilitation CentreDr. P.K. Sethi Rehabilitation Centre
Santokba Durlabhji Hospital, JaipurSantokba Durlabhji Hospital, Jaipur
First private hospital in
the country to have
prosthetics and orthotics
center

3. Dr. P.K. Sethi Rehabilitation Centre

4. (Dr. P.K. Sethi Rehabilitation Centre, Santokba Durlabhji Memorial(Dr. P.K. Sethi Rehabilitation Centre, Santokba Durlabhji Memorial
Hospital, Jaipur ) Started in 1985 by Late Dr. P.K. Sethi.Hospital, Jaipur ) Started in 1985 by Late Dr. P.K. Sethi.
INNOVATOR OF JAIPUR FOOT
Dr. Pramod Karan Sethi
(28-11-1927 - 06-01-2008 )

5. Transfemoral socketTransfemoral socket
Quadrilateral socketQuadrilateral socket
- Introduced in 1940’s. Still in use.Introduced in 1940’s. Still in use.
- Has comfort and stability problem.Has comfort and stability problem.
- Ischial seat at horizontal brim serves as seat forIschial seat at horizontal brim serves as seat for
ischial tuberosity and the user’s weight isischial tuberosity and the user’s weight is
transferred to the quadrilateral socket through it.transferred to the quadrilateral socket through it.

6. - The narrow AP dimension pushes the ischialThe narrow AP dimension pushes the ischial
tuberosity on ischial seat.tuberosity on ischial seat.
- Large mediolateral dimension cannot preventLarge mediolateral dimension cannot prevent
the excessive abduction of femur.the excessive abduction of femur.
- Distal end of femur is left unsupported inDistal end of femur is left unsupported in
socket, becomes painful and discomfort issocket, becomes painful and discomfort is
also felt at proximal medial part of thigh.also felt at proximal medial part of thigh.

7. - The gluteus medias pulls the femur in to abduction,The gluteus medias pulls the femur in to abduction,
pelvis slides medially and ischial tuberosity shiftspelvis slides medially and ischial tuberosity shifts
along ischial seat of quadrilateral socket.along ischial seat of quadrilateral socket.
- To reduce the pain and discomfort patient leans toTo reduce the pain and discomfort patient leans to
position the torso over the abducted distal end ofposition the torso over the abducted distal end of
femur.femur.
- This deficiency was corrected in new design ischialThis deficiency was corrected in new design ischial
containment socket introduced in 1980.containment socket introduced in 1980.

8. Abducted distal end of
Femur in quadrilateral
socket
Ischial containment
socket

9. - The above deficiency of quadrilateral socket canThe above deficiency of quadrilateral socket can
be corrected by a new socket design which hasbe corrected by a new socket design which has
narrow ML dimension and wider AP dimensionnarrow ML dimension and wider AP dimension
chosen in such a way that ischial tuberosity andchosen in such a way that ischial tuberosity and
a portion of the ramus of the ischium is containeda portion of the ramus of the ischium is contained
within the socket.within the socket.
- This narrow ML socket configuration also hasThis narrow ML socket configuration also has
high lateral wall which provides mediallyhigh lateral wall which provides medially
directed reactive force to the greater trochanter.directed reactive force to the greater trochanter.

10. - In this the abduction angle of the femur in theIn this the abduction angle of the femur in the
stump more closely resembles the femur in thestump more closely resembles the femur in the
sound extremity in all phases of the user’s gaitsound extremity in all phases of the user’s gait
thus greatly reducing the characteristic limp.thus greatly reducing the characteristic limp.
- This design is called N.S. N.A. socket (NormalThis design is called N.S. N.A. socket (Normal
shape Normal alignment or a CAT-CAMshape Normal alignment or a CAT-CAM
(contoured, adducted trochanteric, controlled(contoured, adducted trochanteric, controlled
aligned method) socket.aligned method) socket.

11. Suction socketSuction socket
- Germans first used the concept of creatingGermans first used the concept of creating
relative vacuum inside the socket to berelative vacuum inside the socket to be
effective for suspension.effective for suspension.
- Skin must be pliable and free of scarring.Skin must be pliable and free of scarring.
- Positive mould rectification to ensure skinPositive mould rectification to ensure skin
remains in contact with socket withoutremains in contact with socket without
constricting the blood vessels.constricting the blood vessels.

12. - Valve is installed in socket and is opened andValve is installed in socket and is opened and
closed every time donning and doffing theclosed every time donning and doffing the
prosthesis.prosthesis.
- Concentration of vacuum in particular areaConcentration of vacuum in particular area
will damage in skin.will damage in skin.
- Skin problems and volume fluctuations has toSkin problems and volume fluctuations has to
be kept in mind.be kept in mind.

13. - Has to be donned in standing position soHas to be donned in standing position so
bilateral cases are difficult.bilateral cases are difficult.
- Balancing problems in old age and upper limbBalancing problems in old age and upper limb
dysfunction are contraindication.dysfunction are contraindication.

14. ICEROSSICEROSS
- Icelandic roll-on suction socket.Icelandic roll-on suction socket.
- Pliable liner of silicone rubber rolled on to stump andPliable liner of silicone rubber rolled on to stump and
attached to cord at distal tip of liner and draw the liner-attached to cord at distal tip of liner and draw the liner-
limb combination in to the socket.limb combination in to the socket.
- Can be done in sitting so bilateral cases can be taken up.Can be done in sitting so bilateral cases can be taken up.
- Better than suction socket as volume changes can beBetter than suction socket as volume changes can be
handled.handled.

15. Prosthetic kneeProsthetic knee
1.1. Most complex among all prostheticMost complex among all prosthetic
components due to various needscomponents due to various needs
- To support body weight.- To support body weight.
- To facilitate smooth motion during walking.- To facilitate smooth motion during walking.
- Accommodate large range of motion- Accommodate large range of motion

16. 2. Simple mechanical to computer control2. Simple mechanical to computer control
- Single axis knee joint.- Single axis knee joint.
- Hydraulic or Pneumatic knee joint.- Hydraulic or Pneumatic knee joint.
- Polycentric knee joint.- Polycentric knee joint.
- Microprocessor controlled knee.- Microprocessor controlled knee.

17. 3. Single axis3. Single axis
- Most simple, least expensive and most- Most simple, least expensive and most
maintainence free.maintainence free.
- For low activity patients.- For low activity patients.
-Allows comfortable walking at one gait speed.-Allows comfortable walking at one gait speed.
- Major biomechanical deficiency that it has no- Major biomechanical deficiency that it has no
inherent stability.inherent stability.

18. On standing, muscle power of the amputee hasOn standing, muscle power of the amputee has
to be used to maintain knee in extension.to be used to maintain knee in extension.
- For this reason it is not a good option in elderlyFor this reason it is not a good option in elderly
amputees with medical problems.amputees with medical problems.
- Manual lock may be there to prevent- Manual lock may be there to prevent
buckling during standing.buckling during standing.

19. Stance control kneeStance control knee
- Most commonly used prosthetic knee worldwideMost commonly used prosthetic knee worldwide
it has a weight activated friction brake.it has a weight activated friction brake.
- As the limb is loaded in early stance, the brake isAs the limb is loaded in early stance, the brake is
engaged and resulting friction holds the kneeengaged and resulting friction holds the knee
securely.securely.

20. - When unloaded, brake is released and knee isWhen unloaded, brake is released and knee is
allowed to flex.allowed to flex.
- Good to use for fresh amputees and for thoseGood to use for fresh amputees and for those
with limited walking due to medical reasons.with limited walking due to medical reasons.
- For bilateral cases it is very useful.For bilateral cases it is very useful.
- Not good for high speed walking.Not good for high speed walking.

21. Hydraulic or fluid controlled kneesHydraulic or fluid controlled knees
- Prosthetic knee which incorporates hydraulicProsthetic knee which incorporates hydraulic
unit to control knee motion.unit to control knee motion.
- It provides a smoother more normal swingIt provides a smoother more normal swing
phase movement.phase movement.
- Hydraulic knees are smaller, lighter andHydraulic knees are smaller, lighter and
costly as compared to pneumatic knees.costly as compared to pneumatic knees.
- They require periodic servicing.They require periodic servicing.

22. - This is indicated when amputee is capable ofThis is indicated when amputee is capable of
walking at variable speeds.walking at variable speeds.
- In very cold climate, thickening of hydraulicIn very cold climate, thickening of hydraulic
fluid may reduce its efficiency. It is not so influid may reduce its efficiency. It is not so in
pneumatic knees.pneumatic knees.
- Mauch knee is purely hydraulic and composed ofMauch knee is purely hydraulic and composed of
aluminium, weighting 1140 grams and flexionaluminium, weighting 1140 grams and flexion
range isrange is 1150
..

23. Pneumatic kneePneumatic knee
- They are similar to hydraulic knees except thatThey are similar to hydraulic knees except that
air is used as control medium. Their function isair is used as control medium. Their function is
not effected by very cold climate so usednot effected by very cold climate so used
commonly in such areas.commonly in such areas.
- The primary limitation to pneumatic knees isThe primary limitation to pneumatic knees is
that they may not provide sufficient resistancethat they may not provide sufficient resistance
for very vigorous activities because gases suchfor very vigorous activities because gases such
as air are compressible.as air are compressible.

24. Hybrid kneeHybrid knee
- These types of knees provide features ofThese types of knees provide features of
hydraulic as well as pneumatic design.hydraulic as well as pneumatic design.

25. Polycentric knee jointPolycentric knee joint
- Multiple articulations they contain with 4 axis- Multiple articulations they contain with 4 axis
points which are connected by 4 linkage bars.points which are connected by 4 linkage bars.
- For high levels of activities, more stable andFor high levels of activities, more stable and
better suited for uneven terrain.better suited for uneven terrain.
- Four bar linkage allows variable resistanceFour bar linkage allows variable resistance
through out the gait cycle to more closelythrough out the gait cycle to more closely
mimic normal waling.mimic normal waling.
- A key distinction is that the functional centerA key distinction is that the functional center
of rotation is generally located out side theof rotation is generally located out side the
knee joint .knee joint .

27. - The ICOR (Instantaneous Center of Rotation)The ICOR (Instantaneous Center of Rotation)
is located posteriorly and proximally to theis located posteriorly and proximally to the
mechanical knee axis. This posterior positionmechanical knee axis. This posterior position
makes the knee inherently stable because themakes the knee inherently stable because the
GRF (ground reaction force) is located farGRF (ground reaction force) is located far
anteriorly thus generating a strong extensionanteriorly thus generating a strong extension
moment .moment .
- As the amputees starts flexing the knee, theAs the amputees starts flexing the knee, the
ICOR changes, typically it moves moreICOR changes, typically it moves more
anteriorly and distally with each additionalanteriorly and distally with each additional
degree of knee flexion.degree of knee flexion.

28. - Polycentric knees offer yet another mechanicalPolycentric knees offer yet another mechanical
advantage that is additional toe clearance at midswingadvantage that is additional toe clearance at midswing
reducing the risk of tripping on environmentalreducing the risk of tripping on environmental
obstacles.obstacles.
- Polycentric knees also works very well in bilateralPolycentric knees also works very well in bilateral
patients.patients.
- Newly designed polycentric knees are now available toNewly designed polycentric knees are now available to
minimize the protrusion beyond the socket in flexion.minimize the protrusion beyond the socket in flexion.
This design is ideal for knee disarticulation and veryThis design is ideal for knee disarticulation and very
long above knee stumps.long above knee stumps.

29. DisadvantagesDisadvantages
- Increased cost, high weight and need forIncreased cost, high weight and need for
servicing.servicing.
- Flexion range decreased so patient can’t crouchFlexion range decreased so patient can’t crouch
or squat.or squat.
- Remotion knee 80 US $ made up of polymersRemotion knee 80 US $ made up of polymers
and stainless steel, weight 400 gms and 165and stainless steel, weight 400 gms and 1650
knee flexion allows to squat or crouch.knee flexion allows to squat or crouch.

30. Microprocessor kneeMicroprocessor knee
- New and most advanced. It has a- New and most advanced. It has a
- Sensor microprocessor,Sensor microprocessor,
- Software,Software,
- Resistance systemResistance system
- Battery.Battery.
The knees internal computer (theThe knees internal computer (the
microprocessor) controls an internal fluid whichmicroprocessor) controls an internal fluid which
may be hydraulic or pneumatic microprocessor,may be hydraulic or pneumatic microprocessor,
monitors each phase of gait cycle using a seriesmonitors each phase of gait cycle using a series
of sensors.of sensors.

31. Continuous monitoring and control of fluidContinuous monitoring and control of fluid
allows the processor to make adjustments inallows the processor to make adjustments in
resistance so one can walk at various speedsresistance so one can walk at various speeds
and walk more safely up and down.and walk more safely up and down.

32. Different prosthetic componentsDifferent prosthetic components
Shock absorbing pylon – Telescoping springShock absorbing pylon – Telescoping spring
loaded pylon to act as shock absorber whileloaded pylon to act as shock absorber while
descending stairsdescending stairs

33. Positional RotatorPositional Rotator
–– It is locking turntable that allows amputees toIt is locking turntable that allows amputees to
passively rotate the lower leg while sitting,passively rotate the lower leg while sitting,
dressing and doing other ADL.dressing and doing other ADL.
Torque absorberTorque absorber
–– It permits controlled transverse rotation toIt permits controlled transverse rotation to
absorb stresses before it reaches the stump.absorb stresses before it reaches the stump.
- More useful in bilateral amputees to provideMore useful in bilateral amputees to provide
rotary motion thus facilitating reciprocal gait.rotary motion thus facilitating reciprocal gait.

34. Below knee socketBelow knee socket
1. Open ended1. Open ended
- Problem of distal edema- Problem of distal edema
- Proprioceptive input is less- Proprioceptive input is less
- We often use aluminium as- We often use aluminium as
socket material which issocket material which is
time tested, durable, cheaptime tested, durable, cheap
and rapid fit limb.and rapid fit limb.
- Very successful design since- Very successful design since
last 40 years.last 40 years.

35. Total contact PTB/PTS socket
Areas requiring pressure relief in PTB socket
Anterior Lateral Posterior

36. Total contact PTB/PTS socket
A- Anterior B-Lateral view C- Posterior view
Pressure-tolerant areas in a PTB socket

37. Total contact socketTotal contact socket
1.1.More surface area in contactMore surface area in contact
2. Better proprioceptive input2. Better proprioceptive input
3. Better tolerated by diabetic3. Better tolerated by diabetic
amputeesamputees

38. Silicone linerSilicone liner
- It is protective cover made up of flexibleIt is protective cover made up of flexible
cushioning material to reduce movement andcushioning material to reduce movement and
chafing between the skin and the socket.chafing between the skin and the socket.
- For stumps with grafted skin and very skinnyFor stumps with grafted skin and very skinny
stumps with prominent bony landmarks.stumps with prominent bony landmarks.
- Very soft, delicate and costly material.Very soft, delicate and costly material.
- Uncertain durability.Uncertain durability.

39. Prosthetic foot pieceProsthetic foot piece

40. CROSS SECTIONCROSS SECTION
SACH FOOTSACH FOOT
Wooden keel extending up to metatarsal region

41. It has a rigid keelIt has a rigid keel
1.1.Which does not allow freedom ofWhich does not allow freedom of
movement needed for squatting.movement needed for squatting.
2.2.sitting cross legged.sitting cross legged.
3. walking on uneven terrain.3. walking on uneven terrain.

42. Inversion and eversionInversion and eversion
Permitted in a very limited range inPermitted in a very limited range in
SACH foot by compression of theSACH foot by compression of the
heel pad.heel pad.

43. Jaipur footJaipur foot
Culture specific Innovation and simpleCulture specific Innovation and simple
solution to a very complex problemsolution to a very complex problem

44. 1.1. FlexibilityFlexibility
Permit squattingPermit squatting
Cross legged sittingCross legged sitting
Walking on uneven terrainWalking on uneven terrain

45. 2. Water proof exterior allows working in2. Water proof exterior allows working in
fields for farmers.fields for farmers.

46. 3. Can be worn without shoes (bare foot3. Can be worn without shoes (bare foot
walking) so allows one to enter places ofwalking) so allows one to enter places of
worship (Temple, Mosque, Gurudwara)worship (Temple, Mosque, Gurudwara)
and kitchen.and kitchen.
Can be worn with shoes with equal easeCan be worn with shoes with equal ease..

47. 4.4. It is made up of locally availableIt is made up of locally available
rubbers, wood and metals sorubbers, wood and metals so
uninterrupted supply can be ensured.uninterrupted supply can be ensured.
5. Can be attached to any type of shank.5. Can be attached to any type of shank.

48. DurabilityDurability
6. W6. We expect it to last for at least 3 years whene expect it to last for at least 3 years when
used by moderately active person.used by moderately active person.
Shelf lifeShelf life
7. Since it is made up of materials which7. Since it is made up of materials which
doesn't deteriorate with time when kept indoesn't deteriorate with time when kept in
normal environment so shelf life is good andnormal environment so shelf life is good and
can be stored.can be stored.

49. CostCost
Cheapest prosthetic foot piece available. It isCheapest prosthetic foot piece available. It is
approximately Rs.600/- (US $10)approximately Rs.600/- (US $10)

50. Shortcomings in Jaipur footShortcomings in Jaipur foot

51. 1. Weight 850 grams1. Weight 850 grams
2. Lack of material standardization.2. Lack of material standardization.
3. Labor intensive fabrication (non3. Labor intensive fabrication (non
standardized).standardized).
4. Available only in one colour.4. Available only in one colour.
5. Quality control in such a situation is not5. Quality control in such a situation is not
possible.possible.

52. Break pointsBreak points
The common break points and areas of wear andThe common break points and areas of wear and
tear aretear are
1. Carriage bolt1. Carriage bolt
2. Universal joint2. Universal joint
3. Proximal part of heel3. Proximal part of heel
4. MTP joint area4. MTP joint area
5. Discoloration5. Discoloration of outer cover.of outer cover.

53. GoalsGoals
1.1.Weight reduction.Weight reduction.
2.2.Material characterization.Material characterization.
3.3.Minimizing manufacturing steps withMinimizing manufacturing steps with
standardization.standardization.
Keeping affordability in mind.Keeping affordability in mind.

54. ModificationModification
what we have tried?what we have tried?

55. 1. Polyurethane1. Polyurethane
In a research project funded by Department ofIn a research project funded by Department of
Science and Technology, Government ofScience and Technology, Government of
IndiaIndia
Collaborating institutionsCollaborating institutions
1. Indian Institute of Technology, Mumbai.1. Indian Institute of Technology, Mumbai.
2. National chemical Laboratories, Pune.2. National chemical Laboratories, Pune.

56. Results were not encouraging as foot piecesResults were not encouraging as foot pieces
were breaking in three to six months timewere breaking in three to six months time
and were very slippery.and were very slippery.

57. 2.2. Carriage BoltCarriage Bolt
Iron carriage bolt now replacedIron carriage bolt now replaced
stainless steel.stainless steel.

58. It has not been recognized in the developedIt has not been recognized in the developed
world because of absence of biomechanicalworld because of absence of biomechanical
evaluation.evaluation.

59. In the year 2011 and 2012 we work withIn the year 2011 and 2012 we work with
Michigan Technological University, USA toMichigan Technological University, USA to
replace microcellular rubber with EVA (ethylenereplace microcellular rubber with EVA (ethylene
vinyl acetate).vinyl acetate).

60. MCR heel and forefoot blocks wereMCR heel and forefoot blocks were
replaced by EVA (Ethylene Vinylreplaced by EVA (Ethylene Vinyl
Acetate)Acetate)
35 shore A EVA
65 shore A EVA
45 shore A EVA

61. Due to vulcanization problem the durability ofDue to vulcanization problem the durability of
the foot piece got compromised.the foot piece got compromised.
Following this nylon 6 foam was tried which alsoFollowing this nylon 6 foam was tried which also
did not work.did not work.

62. In the year 2014, National Science Foundation,In the year 2014, National Science Foundation,
USA sanctioned a research project to us forUSA sanctioned a research project to us for
improvisation of Jaipur foot in association withimprovisation of Jaipur foot in association with
Ohio State University, USA and MalviyaOhio State University, USA and Malviya
National Institute of Technology, Jaipur.National Institute of Technology, Jaipur.
This work will continue up to 2017.This work will continue up to 2017.

63. Seattle foot Introduced in 1985
- Economic
- Efficient
- Less maintainence
- Resembles real foot.

64. It has a delrin keel which is a spring to
improveimprove running. It is the first foot to have
effective energy absorbing system.

65. The prosthetics using the simple energy-
absorption were only effective for slow walking.
The Seattle Foot became the first device that
genuinely attempted to replicate the natural
movement of the foot during various human
gaits.

66. Dynamic response footDynamic response foot
Characterized by spring like keel that extendsCharacterized by spring like keel that extends
from the toe region to the calf region. It isfrom the toe region to the calf region. It is
made up of carbon fiber composites.made up of carbon fiber composites.
- Deflects under load.Deflects under load.
- Stores potential energy.Stores potential energy.

67. -Releases in the later part of the stance phase.
-Needed for recreational and sports activities.

68. Flexible keel footFlexible keel foot
Innovative design made from solid rubber keelInnovative design made from solid rubber keel
extending beyond the metatarsal region in to theextending beyond the metatarsal region in to the
toe area of foot. This makes the forefoot verytoe area of foot. This makes the forefoot very
flexible and facilitates rollover and amputees canflexible and facilitates rollover and amputees can
walk easily.walk easily.

69. Multiaxial ankle - footMultiaxial ankle - foot
It contains a mechanism that offers a limitedIt contains a mechanism that offers a limited
range of coronal plane inversion and eversion asrange of coronal plane inversion and eversion as
well as sagittal plane plantar flexion andwell as sagittal plane plantar flexion and
dorsiflexion. It is helpful in negotiating unevendorsiflexion. It is helpful in negotiating uneven
terrain. This contributes to socket comfort byterrain. This contributes to socket comfort by
absorbing some of the impacts of walking.absorbing some of the impacts of walking.

70. Flex-Foot Cheetah Blades Cost of each side approx.
US$ 18000 (INR 11,70,000/-)
Carbon Copy

71. Oscar Pistorius with running bladesOscar Pistorius with running blades

72. - These blades are transtibial prosthesis which areThese blades are transtibial prosthesis which are
designed to store kinetic energy, like spring,designed to store kinetic energy, like spring,
allowing the wearer to jump and run effectively.allowing the wearer to jump and run effectively.
- These are made up of carbon-fiber-reinforcedThese are made up of carbon-fiber-reinforced
polymer which is strong and light material.polymer which is strong and light material.
- Blades are bolted to carbon fiber socket.Blades are bolted to carbon fiber socket.
- Custom made spike pads are attached on theCustom made spike pads are attached on the
blade.blade.
- Because of the curved design the blades have toBecause of the curved design the blades have to
be slightly longer than the runners biological legbe slightly longer than the runners biological leg
and foot would be.and foot would be.

73. OsseointegrationOsseointegration
Yet to begin in India.Yet to begin in India.
The metal implant is inserted in to the medullaryThe metal implant is inserted in to the medullary
cavity of residual long bone and a tubular component,cavity of residual long bone and a tubular component,
with a surface self-tapping screw thread that engageswith a surface self-tapping screw thread that engages
the inner aspect of the cortex. The connectingthe inner aspect of the cortex. The connecting
component called abutment, is attached to lower endcomponent called abutment, is attached to lower end
of implant.of implant.
Abutment projects out side the skin to be attached toAbutment projects out side the skin to be attached to
the prosthetic component.the prosthetic component.

74. ThanksThanks