Upper limb prosthesis (pmr)

PMR PG Teaching

1. UPPER LIMB PROSTHESISUPPER LIMB PROSTHESIS
Astha PatniAstha Patni

2. IntroductionIntroduction
•Upper limb prosthesis designed to
replace, as much as possible, the
function or appearance of a missing
limb or body part
•Prosthesis can replace some grasping
and manipulating functions of hand
•No sensory feedback
•Role of dominant function replaced to
contra-lateral hand and prosthesis
assists bimanual function

3. •A successful prosthesis
–comfortable to wear
–easy to don and doff
–light weight and durable
–cosmetically pleasing
–must function well mechanically
–have reasonable maintenance
–motivation of the individual

4. •Factors
–Amputation level
–Expected function of the prosthesis
–Cognitive function of the patient
–Vocation of the patient
–Avocational interests of the patient
–Cosmetic importance of the prosthesis
–Financial resources of the patient

5. •Reasons for upper limb amputation
–0-15 years: Correction of a congenital
deformity or tumor
–15-45 years: Trauma, tumor
–60 years: Rare ; tumor or medical
disease

6. AMPUTATION LEVELSAMPUTATION LEVELS
•Transphalangeal amputation : Resection of the
thumb or fingers at distal interphalangeal (DIP),
proximal interphalangeal (PIP), or
metacarpophalangeal (MCP) levels, or at any
level in between
•Transmetacarpal amputation : Resection
through the metacarpals
•Transcarpal amputation : Resection through
the carpal bones
•Wrist disarticulation: Transection between the
carpals and radius/ulna

7. AMPUTATION LEVELSAMPUTATION LEVELS
•Transradial amputation : Below-elbow amputation
(may be classified as long, medium, or short)
•Elbow disarticulation: Transection through the elbow
joint
•Transhumeral amputation - Above-elbow (Standard
length is 50-90% of humeral length.)
•Shoulder disarticulation: Transection through the
shoulder joint
•Interscapulothoracic disarticulation (forequarter):
Amputation removing the entire shoulder girdle (scapula
and all or part of the clavicle

9. TYPES
•Body powered or conventional
•External powered or electric
•Cosmetic or passive
•Hybrid

10. Body powered or Body powered or
conventionalconventional
•Pros
–low cost
–Moderately lightweight
–Most durable
•Cons
–Most body movement to operate
–Most harnessing
–Least satisfactory appearance

11. External powered or electricExternal powered or electric
•Pros
–Moderate or no harnessing
–Least body movement to operate
–Moderate cosmesis
–More function – proximal levels
•Cons
–Heaviest
–Most expensive
–High maintenance
–Limited sensory feedback

12. Cosmetic or passiveCosmetic or passive
•Pros
–Most lightweight
–Best cosmesis
–Least harnessing
•Cons
–High cost if custom made
–Least function

13. Upper limb prosthesisUpper limb prosthesis
•Prosthetic components
–Terminal devices
–Wrists
–Elbows
–Shoulders
•Socket
•Suspension

14. Terminal devicesTerminal devices
•Functional activities of hand
–Non prehensile
–Prehensile

15. Terminal devicesTerminal devices
•Non prehensile
–Touching, feeling, pressing down with
fingers, tapping, vibrating the cord of
musical instrument, lifting or pushing
with hand
•Prehensile
–Precision grip (i.e. pincher grip), Tripod
grip, Lateral grip, Hook power grip,
Spherical grip

16. Terminal devicesTerminal devices
•Active
–Hooks
–Functional hands
–Activity specific devices
•Passive
–Cosmetic hands

17. Hook / Hand
Mechanical
Electrical
VO VC Electrical Myoelectric
Digital Proportional
Passive
Active

18. Terminal devicesTerminal devices
•Lack sensory feedback
•Limited mobility and dexterity
•Hand – three-jaw chuck
•Hook – lateral pinch

19. Terminal devicesTerminal devices
•VO
–Practical
–In closed position, by springs
–Patient pulls the cable to open
–Prehensile force – spring
•VC
–Physiological
–In open position
–Patient pulls the cable to close
–Prehensile force – patient
–Greater proprioceptive input

20. Voluntary-Closing HooksVoluntary-Closing Hooks
•APRL hook
developed by the
Army Prosthetics
Research
Laboratory

21. Voluntary-Opening Hook Voluntary-Opening Hook
Terminal DevicesTerminal Devices
•Hosmer-Dorrance work hooks
•Sierra two-load hook
• United States Manufacturing
Company (USMC) hook
• CAPP terminal device (originally
developed at the Child Amputee
Prosthetics Project at UCLA)
•Otto Bock and Hugh Steeper

22. . Voluntary-opening hook-. Voluntary-opening hook-
type terminal devicetype terminal device

23. Voluntary-Closing HandsVoluntary-Closing Hands
Otto Bock system
hands

24. Voluntary-Opening HandsVoluntary-Opening Hands
•Becker Plylite Hand
•Becker Lock-Grip and Imperial
Hands.
•Robin-Aids Mechanical Hand
•Robin-Aids Soft Mechanical Hand
•Sierra Voluntary-Opening Hand
•Hosmer-Dorrance Functional
Hands

25. ELECTRIC TERMINAL DEVICESELECTRIC TERMINAL DEVICES
Hand like shape
•Otto Bock System
Electric Hands
•Steeper Electric
Hands
Not having hand like
shape
•Otto Bock System
Electric Greifer
•Hosmer NU-VA
Synergetic
Prehensor
•Steeper Powered
Gripper
• NY-Hosmer
Prehension Actuator

26. Otto Bock System
Electric Hand (left)
and Steeper
Electric Hand
(right). A with
mechanism covered
by handlike shells;
B with internal
mechanism
exposed.

28. •A "palmar" and B
lateral views of the
Steeper Powered
Gripper (left), Otto
Bock System
Electric Greifer
(center), and Hos-
mer NU-VA
Synergetic
Prehensor (right).

29. Myoelectric controlMyoelectric control
•tranradial myoelectric
prosthesis (Otto Bock
type) The system
uses two myoelectric
sites on the residual
limb. the signal flow in
a two-site, two-
function myoelectric
hand prosthesis

31. Activity specific devicesActivity specific devices
•Farming
•Construction
•Cooking
•Photography
•Sports: golf, fishing, skiing

32. Cosmetic glovesCosmetic gloves
•Digit, hand, extend
till elbow
•Custom made
silicone cosmetic
covers – expensive
and difficult to
maintain

33. Prosthetic wristsProsthetic wrists
•Provide receptacle for connecting
terminal device
•Pronosupination or flexion based on
functional activities of patient

34. Prosthetic wrists Prosthetic wrists
Types
•Mechanical
–Pronosupination
•Friction (Can rotate)
•Quick-disconnect
•Spring-assisted (B/L amputee)
–Flexion (B/L amputee , longer side)
•Spring-assisted internal or external

35. Prosthetic wristsProsthetic wrists
•Electric (B/L trans-humeral)
–Pronosupination
•Myoelectric (B/L amputee)
•Switch control

36. Friction wrist units. Friction wrist units.

37. Round and oval configurations Round and oval configurations
of constant friction wrist unitsof constant friction wrist units

38. Quick-change wrist unitsQuick-change wrist units

39. Flexion wrist unitsFlexion wrist units

40. Electric wrist unitsElectric wrist units
•The Otto Bock
Electric Wrist
Rotator. The
rotator, shown
alone at the
bottom,
mechanically and
electrically
interfaces with the
quick-disconnect
adaptor of the
System Electric
Hand or Greifer

41. Prosthetic elbowsProsthetic elbows
Classification
•Body-powered elbow
–External with or without spring assisted
flexion (elbow disarticulation)
–Internal, with or without spring assisted
flexion
–Internal, with rotating turntable (allows
internal/ external rotation)

42. Prosthetic elbowsProsthetic elbows
•Externally powered elbow
–Digital switch control
–Proportional switch control
–Digital myoelectric control
–Proportional myoelectric control
•Passive elbow
–Manual lock

43. Elbow units Elbow units
Flexible hinges Rigid hinges

44. Elbow Elbow
Polycentric hinges Step up hinges

45. ELBOW UNITELBOW UNIT
OUTSIDE LOCKING INSIDE LOCKING

46. Electrical powered elbowsElectrical powered elbows
•Boston Elbow,
• NY-Hosmer Electric Elbow,
• Utah Arm.

These elbows differ from one
another in mechanical configuration,
drive mechanism, and control
options.

48. Prosthetic socketsProsthetic sockets
Functions
–Comfortable residual limb – prosthesis
interface
–Efficient energy transference to the
prosthesis
–Secure suspension of the prosthesis
–Adequate cosmesis

49. Prosthetic socketsProsthetic sockets
•Wood
–Chronic edema
–Trophic skin changes
•Plastic
–Total contact
–Decreased weight
–Increased durability

50. Prosthetic socketsProsthetic sockets
•Two layers
•Inner-contoured to the residual limb
•External- gives length and shape
•Components are attached to external
layer

51. Prosthetic socketsProsthetic sockets
•Process
–Negative impression of residual limb
(POP)
–Positive mold
–Modify positive mold (remove from
pressure tolerant and add to pressure
sensitive)
–Transparent / check socket
–Trial fit and modify
–New positive mold
–Final socket

52. Negative mold

53. Positive mold

54. socket

55. Various socketsVarious sockets
•Wrist disarticulation socket
•long Below elbow socket
•Short below elbow socket
•Very short below elbow socket
[ Split sockets]
Muenster sockets

56. •Elbow disarticulation socket
•Standard above elbow socket
•Short above elbow socket
•Shoulder disarticulation socket
•Forequarter amputation socket

57. Suspension systemsSuspension systems
•Functions
–Suspension – securing prosthesis to
residual limb
–Control of prosthesis / terminal devices
•Types
–Harness
•Figure of 8 (traditional)
•Chest strap (proximal amputation)
•Shoulder saddle (proximal amputation)

58. Harness

59. Suspension systemsSuspension systems
•Self suspension
–Condylar
–Muenster (Self suspending; Not
preferred in B/L transradial amputation)
–Northwestern
•Semisuction
–Hypobaric
–Semisuction
•Suction
–Full suction
–Silicone sock
Suction suspension
preferred for
Tranhumeral
amputee with normal
contrlateral limb

60. •Sock
•Interface between residual limb and
socket
•Layers adjustable to volume changes
•Protect skin and improve hygiene
•Socks with special silicone band and
socket with one way valve are used in
semisuction type of suspension systems

61. Silicone suction suspensionSilicone suction suspension
•Kristinsson in 1986
•Improved suspension with negative
atmospheric pressure
•Reduction of shear forces on skin
•Allows volume adjustment with
residual limb girth changes
•Simplified donning, better elbow
range of motion, lighter

62. Silicone suction suspensionSilicone suction suspension
•Silicone sleeve with distal
attachment pin that fits into shuttle
lock mechanism in socket
•Rolls silicone liner directly over skin
after spraying alcohol
•Socks over silicone to improve fit

63. Silicone suction suspensionSilicone suction suspension
•Patients with problems of skin
integrity
–Skin grafting for burns,
–degloving injury,
–insensate skin (diabetes, scleroderma),
–adhesive scar tissue

64. Control mechanismsControl mechanisms
•Body powered (harness)
–Scapular abduction
–Chest expansion
–Shoulder depression, extension,
abduction, flexion
–Elbow flexion, extension
•Discomfort
•Less cosmetic

65. MECHANICS OF THE BELOW-ELBOW
(TRANSRADIAL) CONTROL SYSTEM

66. •Glenohumeral joint
flexion for
operating a
terminal device.

67. HEAVY-DUTY HEAVY-DUTY
TRANSRADIAL HARNESS TRANSRADIAL HARNESS

68. BILATERAL TRANSRADIAL BILATERAL TRANSRADIAL
HARNESSHARNESS

69. TRANSHUMERAL CONTROL TRANSHUMERAL CONTROL
SYSTEMSYSTEM
Two types of
control cable
1.Elbow
flexion/terminal
device control
cable
2.Elbow lock
control cable

70. Trans humeral hareness controlTrans humeral hareness control

71. The operating sequence of the two The operating sequence of the two
cable systems cable systems
•Tension applied to the elbow
flexion/terminal device control cable causes
the elbow to flex;
• When the desired angle of elbow flexion is
achieved, the rapid sequential application
and release of tension on the elbow lock
control cable locks the elbow
• With the elbow locked, the reapplication of
tension on the elbow flexion/terminal device
control cable permits operation of the
terminal device

72. SHOULDER DISARTICULATION SHOULDER DISARTICULATION
HARNESSHARNESS

73. Control mechanismsControl mechanisms
•Externally powered prostheses
•Electric motors inside prosthesis for
wrist rotation / elbow flexion or
extension
•Motors controlled by switches,
myoelectric signals, acoustic signals

74. Control mechanismsControl mechanisms
Switch
•Inside or outside socket
•Activated on contact by amputee

75. Control mechanismsControl mechanisms
Myoelectric controls
•Electrical activity generated during
muscle contraction to control flow of
energy from a battery to a motor in
prosthetic device
•Antagonistic muscles in distal portion
with normal voluntary activity

76. Control mechanismsControl mechanisms
Myoelectric controls
•Electrodes inside socket detect muscle
action potentials, amplify them to turn
on motor which brings about
movements
•Single channel: two electrode sites, one
for each function (open & close terminal
device)
•Multi-channel: single electrode,
amplitude of signal determines function

77. Control mechanismsControl mechanisms
Myoelectric controls
•High cost
•Low reliability
•Heavy (motors, batteries)
–India: electrodes rust quickly because of
sweat, electronic circuits fail due to dust
/ sweat

78. Prostheses by level of Prostheses by level of
amputationamputation

79. Prostheses by level of Prostheses by level of
amputationamputation
Partial hand
•Prosthesis not necessary
•Surgical reconstruction – opposition –
for prehension with proprioception

80. Prostheses by level of Prostheses by level of
amputationamputation
•Wrist disarticulation
–Distal radial-ulnar articulation preserved
for prono-supination
–Socket: tapered and flattened distally
forming an oval shape
–Wrist unit: thin, to minimize length
–Cosmetically: trans radial

81. Prostheses by level of Prostheses by level of
amputationamputation
Transradial amputation
Classification (based on length)
•Very short (<35%): rigid elbow hinges
•Short (35-55%): <60º pronosupination,
flexible elbow hinges
•Long (55-90%): 60-120 º
pronosupination, flexible elbow hinges

82. Below elbow prosthesis

83. Prostheses by level of Prostheses by level of
amputationamputation
Transradial amputation with decreased
elbow ROM
•Polycentric elbow joints or split socket
with step-up hinges used to provide
additional flexion
•Decreased elbow flexion power

84. Prostheses by level of Prostheses by level of
amputationamputation
Elbow disarticulation
•Sockets: flat and broad distally (like
epicondyles)
•External elbow joint with cable operated
lock in medial joint
•Suspension: figure of 8, shoulder
saddle, chest strap
•Control system: 2 cables, one to lock
the elbow, other opens terminal device
or flexes elbow

85. Prostheses by level of Prostheses by level of
amputationamputation
Transhumeral amputation
Classification (based on length of
humerus)
•Very short (<30%)
•Short (30-50%)
•Standard (50-90%)

86. Prostheses by level of Prostheses by level of
amputationamputation
Transhumeral amputation
•Sockets:
–Residual limb greater than 35% -
proximal trimline within 1cm of
acromion, suspension with figure of 8,
shoulder saddle, or chest strap
–Residual limb smaller than 35% -
proximal trimline 2.5cm medial to
acromion, suspension with chest strap
or suction socket

87. Prostheses by level of Prostheses by level of
amputationamputation
Transhumeral amputation
•Elbow joint
–Internal elbow joint
•Preferred
•Level of amputation 4 cm or more proximal from
epicondyles
•Allows passive internal / external rotation
•Elbow spring-lift assist available
–External elbow joint
•Distal amputation
•Maintains elbow center with contralateral side

88. Prostheses by level of Prostheses by level of
amputationamputation
Transhumeral amputation
•Control system
–Dual cable (like elbow disarticulation)

89. Above elbow prosthesis

90. Above elbow prosthesis

91. Shoulder disarticulation and Shoulder disarticulation and
forequarter amputationforequarter amputation
•Socket
–Extends to thorax
–Open –frame socket to decrease weight
and heat
•Similar to transhumeral + shoulder
unit

92. Bulk head
Flex / ext
Universal

93. Shoulder disarticulation and Shoulder disarticulation and
forequarter amputationforequarter amputation
•Control:
–Triple cable system
–One for elbow flexion when opposite
humerus is flexed
–Second cable opens terminal device with
chest expansion
–Third cable locks / unlocks elbow with
chin / opposite hand

94. Shoulder disarticulation and Shoulder disarticulation and
forequarter amputationforequarter amputation
•Externally powered prosthesis
preferred
•Passive cosmetic prosthetic
restoration in some patients