WK9- TT Componentry and Feet

Question 1

Regarding TT prosthetic fitting, what are some general concepts ?

Answer 1

Intimate fit of the socket to the residual limb
decrease skin breakdown and forces
alignment to promote best gait

Question 2

What are the basic components that make up a prosthetic ?

Answer 2

Feet, ankles, shock pylons, sockets

Question 3

What forces should you aim to reduce with prosthetic fitting ?

Answer 3

shear, friction, rotation, axial forces

Question 4

Define the total contact theory

Answer 4

pressure is distributed throughout the residual limb, less weight bearing on the patellar tendon,

Question 5

Define the selective loading theory of weight distribution

Answer 5

There are specific areas of the residual limb that are tolerant and intolerant to stress. Load the more tolerant areas.

Question 6

What are some pressure tolerant and intolerant areas ?

Answer 6

tolerant: patellar lig, anterior compartment, medial tibial flare, medial shaft of tibia, posterior compartment

intolerant: patella, lateral tibial flare, anterior tibial tubercle, crest of tibia, distal end of tibia, head of fibula and peroneal nerve, distal end of fibula.

Question 7

Briefly describe a patellar tendon bearing socket

Answer 7

one of most common socket styles
counter balances forces to alleviate pressure over intolerant areas
horizontal and vertical support component
can accommodate volume changes by using a pelite liner

Question 8

Describe a supracondylar socket

Answer 8

high medial and lateral walls that enclose the patella
mediolateral stability
grips the femoral condyles

benefits: helpful for those with shorter residual limbs or knee instability

drawbacks: high profile, patients may think it ugly

Question 9

What is a suspension ?

Answer 9

coupling between residual limb and prosthesis

Question 10

List some common suspension mechanisms

Answer 10

Silesian Belt
Thigh Corset
Cuff Strap
Pin Locking
Sleeve Suspension
Suction
Elevated Vacuum Suspension

Question 11

Which suction mechanism uses a rod that clicks into the prosthetic

Answer 11

pin locking

Question 12

What is the thickest ply of prosthetic sock available /

Answer 12

6

Question 13

At what ply of socks should you consider a prosthetic replacement

Answer 13

> 10

Question 14

What are some factors to consider when selecting a prosthetic foot ?

Answer 14

functional level, ADLs, work, K class

body weight

residual limb

severity of comorbidities

environmental exposure

shoe choices

interaction with other components

prior feet/gait habits

psychology and character

skin tone

B/L limb loss

Question 15

What K level is a SACH advised for ?

Answer 15

house hold ambulators, K1

Question 16

Briefly describe the advantages and disadvantages of a SACH.

Answer 16

advantages: durable, cost effective, lightweight

disadvantages: heel cushion breaks over time, no energy return, not first choice for knee stability

Question 17

What populations are indicated and contraindicated for a SACH?

Answer 17

indicated for:
early post op, pediatric, preparatory,

contraindicated for:
active patients, when knee stability is needed

Question 18

How does a SAFE foot differ from a SACH ?

Answer 18

the SAFE foot has a plantar ligament for a smooth transition during toe off

Question 19

What K level is a single axis foot advised for ?

Answer 19

K1-K2

Question 20

What are the advantages and disadvantages of a single axis foot ?

Answer 20

advantages: promotes knee stability, easier to descend declines

disadvantages: no inversion or eversion, requires service because of moving parts, adds weight, no energy return

Question 21

What are the indications and contraindications for a single axis foot ?

Answer 21

indications: anyone who needs knee stability, shock absorption at heel

contraindications: active patients

Question 22

What K level is advised for a flexible heel ?

Answer 22

K2

Question 23

What are the advantages and disadvantages of a flexible keel ?

Answer 23

advantages: flexible keel, multiaxial, lightweight

disadvantages: less durable, low profile

Question 24

What are the indications and contraindications for a flexible keel ?

Answer 24

Indications: household ambulator, outside limited

contraindications: not for K3, active individuals, not for knee stability

Question 25

What K level is advised for energy storing or dynamic response prosthetic ?

Answer 25

K3-K4

Question 26

What are the advantages and indications of a energy storing or dynamic response prosthetic ?

Answer 26

advantage: responsive, durable, little maintenance

indications: athletes, patients who walk with variable cadence, active patients

Question 27

What K level is a multi axis prosthetic indicated for ?

Answer 27

K2-4

Question 28

What are the advantages and disadvantages of a multi-axis prosthetic ?

Answer 28

advantages: inversion, everion, pf, and df; shock and torque absorption

disadvantages: increased weight, less durable, maintenance required

Question 29

What are the indications and contra indications of a multiaxis prosthetic ?

Answer 29

indications: uneven terrain, transverse shock reduction

contra: weak patients, level surfaces ambulators, obese patients

Question 30

What are the benefits and drawbacks to a hydraulic foot ?

Answer 30

benefits: moderate to high energy return, adjusts to surfaces, smoother rollover phase

drawbacks: expensive, heavy, not as durable

Question 31

What are the pluses and minuses of microprocessor feet ?

Answer 31

actively responds to environment changes, heavier, battery needs nightly recharging, limited to single axis

containdicated for: very high activity, heavy body weight, water dirt or sand, temperature extremes.