PROSTHESIS i A device applied to replace the function of a missing part
1. Keel is in a spring module 2 (-) Spring cushion
3. Medio-lateral motion 4. Light wt.
vii. Flex-walk
1. Has composite graphite 2. Has medio-lateral motion 3. Light wt., carbon color viii. Flex-foot
1. (+) Abosrbs energy
2. Distal Segment is same with flex walk
3. Proximal segment extends upward to form as the shank. Carbon color
4. Light wt.
*Car Quo Walks Foot kaya Light Wt. * Such SAFE Carbon Qud walk M-L motion 2. Articulated Components
a. Presence of mechanical ankle joint b. Heavy but can be adjusted c. Single Axis
i. MC type since, inherent stability ii. DF + PF
d. Multi Axis/ Polycentrics
ii. Shank
1. Exoskeletal (Crustacean) a. MC type of shank
2. Endoskeletal (Central Support/ Pylon) iii. Socket
1. PTB socket
a. MC prescribed
b. (+) Presence of soft insert
i. Provides additional support areas ii. Reduces edema
iii. Improves circulation 2. Hard socket
a. (-) soft insert
i. For Pt’s with good tissue covering and heavy perspiration 3. ISNY socket
a. Icelandic Swedish New York PTB socket b. Thermoplastic materials
c. Thin to dissipate heat, enhances comfort since it is made up of thermoplastic, can be reshaped again.
4. Pressure Tolerant Areas (bulges/ build ups) a. Patellar tendon
b. Pretibial Ms
c. Postero-distal aspect of residual limb d. Popliteal fossa
e. Distal end, medial flare, lateral of Tibia f. Tibial and fibular shafts
5. Pressure Sensitive areas (Reliefs/ channels) a. Anterior crest of tibia
b. Fibular head and neck c. Peroneal/ Fibular nerve d. Anterior Tibia
e. Hamstrings tendon iv. Suspension (Calf supra supra Thigh)
1. Calf suspension a. MC prescribed
b. Provides slight medio-lateral stability 2. Supracondylar suspension
a. High medial and lateral walls, encompasses the femoral condyles) b. Provides better medio-lateral stability
3. Supracondylar-suprapatellar suspension a. High medial-lateral- anterior walls
b. Encompasses the femoral condyles and the patella c. Provides greater medio-lateral stability
4. Thigh corset
a. Medio-lateral stability and additional suspension b. Quads atrophy, heat.
c. Biomechanics (FAA) i. Inset
1. MC used
2. Prosthetic foot and shank is located medially in relation to the socket. ii. Outset
1. Prosthetic foot and shank is located laterally in relation to the socket. iii. Posterior wall is higher than anterior wall
1. Special device: rotator unit
a. Absorbs rotational forces acting on the stump d. AK Prosthesis
i. Foot ankle assembly
1. Single axis MC, for inherent stability ii. Shank
1. Exoskeletal (Crustacean) iii. Knee joint/ mechanism
1. Axis
a. Single i. MC
ii. Knee Flexion - extension b. Polycentric
i. Knee flexion- extension, slight rotation 2. Friction
a. 3 types
i. Constant
1. MC used
2. During Swing phase, friction remains constant all throughout
ii. Variable
1. Increased resistance during acceleration and decelerations
2. Decreased resistance during midswing iii. Fluid control
1. Cadence –dependent motion 2. 2 types
a. Pneumatic - air b. Hydraulic – oil 3. Extension Aid/ Extension stop
a. Extension aid
i. Aids during swing phase b. Extension stop
4. Knee locks a. 2 types
i. Wt. activated ii. Manual lock iv. Socket
1. Quadrilateral sockets a. MC used b. Walls
i. Posterior wall, horizontal shelf for Ischial tuberosity wt. bearing ii. Anterior wall, higher than posterior wall to prevent dislodging of
Ischial tuberosity from the horizontal shelf) d/t translatory and angular pelvic motions.
iii. Lateral wall, Should be pre-adducted to give leverage to the gluteus medius
iv. Medial wall, should accommodate the adductor mucles to prevent adductor roll
v. ALAT anterolateral walls should be 2.5-3” higher than the postero-medial walls
2. Ischial containment socket
a. Ischial tuberosity is within the socket b. Wt. bearing: ascending ischio-pubic ramus v. Suspension (SuPaSiPer)
1. Suction suspension a. MC prescribed b. 4G’s criteria
i. Good tissue covering ii. Good limb length and shape iii. Good single limb balance iv. Good hand strength and dexterity 2. Partial suction with Axillary suspension
3. Silesian bandage
a. Has medio-lateral control b. Pt’s active in sports 4. Pelvic belt
a. Has (B) medio-lateral and rotational control vi. Biomechanics
1. Inset
2. Initial socket flexion = 5o
3. Initial socket adduction =7o
4. Special device e. Speed of ambulation
i. (N) speed = 3mph ii. Single BK = 2-2.5 mph iii. Single AK = 1.5mph
f. Metabolic requirements
i. Wheelchair ambulation = 9% ii. Crutch walking = 60% iii. Single BKA = 10-40% iv. Double BKA = 41%
v. Single AKA = 65% vi. Double AKA = 110%
vii. Single AKA + Single BKA = 75% g. Prosthetic fitting in children
i. Above below elbow 3-6 months ii. Below above knee joint : 8-10 months
iii. Actively controlled Terminal Device - 2 years old iv. Actively controlled elbow joint – 2-3 years old
v. Functional hand - 3 years old
vi. Actively controlled knee joint 3-4 years old h. Gait deviations
i. BK prosthesis (Seen in stance phase)
1. Excessive knee flexion at heelstrike ( >15-20o)
a. Excessive dorsiflexion of prosthetic foot b. Stiff heel cushion
c. Excessive anterior tilt of socket in relation to prosthetic foot
d. Excessive anterior displacement of socket in relation to prosthetic foot 2. Insufficient knee flexion (<15o)
a. Excessive PF of prosthetic foot b. Too soft heel cushion
c. Excessive posterior tilt of socket in relation to prosthetic foot
d. Excessive posterior displacement of socket in relation to prosthetic foot 3. Forward bending
a. Pain on the end of stump/ residual limb 4. Early lateral thrust
a. Excessive inset b. Abducted socket 5. Early knee flexion at push off
a. Excessive DF of prosthetic foot b. Too soft DF bumper/ anterior stop
c. Excessive anterior tilt of socket in relation to the foot
d. Excessive anterior displacement of socket in relation of the foot 6. Delayed knee flexion
a. Excessive plantarflexion of prosthetic foot b. Too stiff DF bumper/ anterior stop
c. Excessive posterior tilt of socket in relation to the foot
ii. AK prosthesis (Seen in stance and swing phase) Stance phase
1. Foot rotation at heel strike
a. Too stiff heel cushion/ PF bumper 2. Foot slap
a. PF bumper too soft/ heel cushion 3. Lateral trunk bending
a. Weak gluteus medius b. Abducted socket c. Short prosthesis
d. Hip abduction contracture e. Pain on distal limb/ insecurity 4. Wide walking base/ abducted gait
a. Pain on crotch area: increased medial wall b. Contracted hip abductors
c. Prosthesis is too long d. Shank is in valgus position e. High medial wall
5. Uneven step length a. Insecurity or fear b. Hip flexion contracture
c. Insufficient knee friction (longer steps taken by the prosthetic leg) 6. Swing-phase whips
a. Medial = external rotation b. Lateral = internal rotation 7. Exaggerated lordosis
a. Contracted back extensors b. Hip flexion contracture
c. Weak abdominals and hip extensors d. Insufficient support from the anterior wall e. Improperly shaped posterior wall Swing Phase
8. Vaulting
a. Prosthesis is too long b. Decrease knee flexion c. Too small socket
d. Excessive PF of prosthetic foot e. Insecurity / fear
f. Inadequate suspension (piston action) g. Manual lock
h. Too tight extension aid i. Insufficient knee friction\ 9. Circumduction
10. Hip hiking
a. Prosthesis is too long 11. Excessive heel rise
a. Forceful hip flexion b. Absence of extension aid c. Insufficient knee friction 12. Insufficient heel rise
a. Manual lock
b. Extension aid too tight/ stiff c. Excessive knee friction 13. Terminal knee impact
a. Criteria Visible and Audible b. Tight extension aid
c. Extension stop is too old/ Resilient d. Knee friction is insufficient e. Pt’s fear of buckling iv. UE prosthesis
a. Components
i. TeD – Terminal Device ii. Inter – Interposing joints
1. Wrist, elbow ,shoulder iii. SO - socket
iv. SU - suspension v. CO – Control cable b. Terminal device
i. Voluntary Opening Hook – MC and Most functional (2 cycles) ii. Voluntary Closing Hook – Most physiological (4 cycle action) iii. Cosmetic Hand – Rigid/ Semi rigid, non functional
iv. Myoelectric hand- muscle rectified by electrodes into hand function v. Motor driven hand – computer generated hand function
c. Interposing Joints i. Wrist
1. Fixed
a. Uses only 1 terminal device 2. Quick change
a. Uses many terminal devices ii. Elbow
1. Mechanical – prepositioned 5-125o elbow flexion
2. Electrical – has more control and versatility iii. Shoulder
d. Socket
i. Standard socket – two-walled socket. (outer & inner wall) 1. MC
2. Inner wall encapsulates the stump
3. Outer wall shaped like the real arm or forearm ii. 3 walled socket – used for infants
1. Outer wall – shaped like the outer arm of the infant 2. Middle wall - preshaped for a year or two, to reduce cost 3. Inner wall - encapsulates the stump
iii. Single walled socket
1. Very short below elbow amputation iv. Muenster type socket
1. Very short Below elbow amputation 2. To gain power
v. Splint-type socket with step up hinge 1. Pt’s with LOM of elbow flexion
2. For every 1o of elbow flexion = 2o at the socket
e. Suspension/ Harness
i. Figure of 8 harness: MC prescribed ii. O-ring harness: adjustable
iii. Figure of 9 harness
iv. Modified shoulder saddle harness – used by patient who performs heavy lifting f. Control cable/ system
i. Bowden control 1. MC
2. Single cable sliding inside a single housing ii. Fair-lead control
1. Single cable sliding inside dual housing v. Upper extremity prosthetic training
a. Don and doff prosthesis
b. Open and close the terminal device c. Hold and release the object d. Transfer objects
e. Perform ADL’s