Transtibial Prosthesis

Question 1

decreased heel lever, increased toe lever

Answer 1

stability

Question 2

stabillity

Answer 2

GRF anterior to knee

Question 3

GRF anterior to knee

Answer 3

promotes knee extension

Question 4

adjustments to socket for stability

Answer 4

socket extension, 
socket posterior to foot, 
foot PF, 
foot anterior to socket, 
softer heel cushion/PF bumper

Question 5

what patients benefit from stability

Answer 5

patients with weak quads

Question 6

increased heel lever, decreased toe lever

Answer 6

mobility

Question 7

mobility

Answer 7

GRF posterior to knee

Question 8

GRF posterior to knee

Answer 8

promotes knee flexion

Question 9

adjustments to socket for mobility

Answer 9

socket flexion,
socket anterior to foot,
foot DF
foot posterior to socket
firm heel cushion/ PF bumper

Question 10

bench alignment

Answer 10

5 flexion
5 adduction
foot slightly medial

Question 11

with greater heel lever/lesser toe lever, there is ______ IC and _________ early stance

Answer 11

abrupt, quick

Question 12

with shorter heel lever, longer toe lever, there is __________ in toe off

Answer 12

delay

Question 13

if PF bumper is soft….

Answer 13

heel lever will be functionally shorter = increase stability

Question 14

if PF bumper is firm…..

Answer 14

it won’t allow for eccentric PF to occur at IC… resulting in quick early stance (increased mobility)

Question 15

if DF bumper is firm (in late stance), patients will complain of:

Answer 15

feeling like they are walking up hill (stability because it won’t allow for excessive DF)

Question 16

pressure tolerant areas

Answer 16

patellar ligament
gastroc belly (posterior compartment)
proximomedial aspect of leg (medial tibial flare/shaft)
anterolateral aspect of leg (lateral fibular shaft)

Question 17

pressure sensitive areas

Answer 17

heal of fibula
tibial crest
tibial condyles
distal ends of fibula/tibia
hamstring tendons

Question 18

poor control of knee

Answer 18

socket tilted into extension or shifted posterior to foot - increase knee stability

Question 19

strong and active patient

Answer 19

socket tilted into flexion or shifted anterior to foot - increase knee mobility

Question 20

excessive medially (in frontal plane)

Answer 20

increase pressure on distal end of fibula

Question 21

excessive laterally (in frontal plane)

Answer 21

increase pressure on fibular head

Question 22

if heel is raised (but no contracture)

Answer 22

excessive weight anteriorly = jeopardizing knee stability

Question 23

if forefoot raised

Answer 23

excessive weight posteriorly = difficult to flex the knee during walking

Question 24

if lateral border is raised

Answer 24

excessive WB medially - pressure of fibular head

Question 25

if medial border is raised

Answer 25

excessive WB laterally - distolateral pain

Question 26

if patient requires 0.5 inch lift under prosthesis, the following may be deficient:

Answer 26

socket too loose heel on prosthetic too soft shank too short

Question 27

if patient requires a 0.5 inch lift under sound leg, the following may be deficient:

Answer 27

socket too tight heel too firm (excessive knee flexion) shank too long

Question 28

anatomic causes of insufficient knee flexion in early stance

Answer 28

``` anterodistal pain poor balance extensor synergy knee extensor contracture knee extensor weakness ```

Question 29

prosthetic causes of insufficient knee flexion in early stance

Answer 29

``` heel too low heel too soft prosthetic foot in PF socket in insufficient flexion socket posterior relative to foot ```

Question 30

anatomic causes of excessive knee flexion in early stance

Answer 30

knee extensor weakness | knee flexor contracture

Question 31

prosthetic causes of excessive knee flexion in early stance

Answer 31

``` heel too high heel too firm prosthetic foot in DF socket in excessive flexion socket anterior relative to foot prosthesis too long ```

Question 32

anatomic/prosthetic causes of early knee flexion in late stance

Answer 32

same as excessive knee flexion in early stance except heel cushion/height irrelevant

Question 33

anatomic/prosthetic causes of delayed knee flexion in late stance

Answer 33

same as insufficient flexion in early stance; except heel cushion height irrelevant

Question 34

excessive lateral thrust

Answer 34

brim shifts laterally - GRF passes medial to the knee excessive adduction of socket excessive lateral displacement of socket (foot inset)

Question 35

excessive medial thrust

Answer 35

brim shifts medially - GRF passes laterally to knee socket abduction medial displacement of the socket - foot outset

Question 36

anterodistal pain causes:

Answer 36

insufficient knee flexion, delayed knee flexion

Question 37

poor balance causes:

Answer 37

insufficient knee flexion, delayed knee flexion; long prosthetic step

Question 38

extensor synergy causes:

Answer 38

insufficient knee flexion, delayed knee flexion

Question 39

hip flexor contracture causes:

Answer 39

long prosthetic step

Question 40

knee extensor contracture causes:

Answer 40

insufficient knee flexion, delayed knee flexion

Question 41

knee extensor weakness causes:

Answer 41

excessive knee flexion, early knee flexion or insufficient knee flexion (as a compensation for keeping GRF anteriorly)

Question 42

knee flexor contractures

Answer 42

excessive knee flexion, early knee flexion, long prosthetic step

Question 43

pain in amputation limb causes:

Answer 43

long prosthetic step (longer time WBing on sound limb)

Question 44

suspension inferring with knee flexion causes:

Answer 44

insufficient knee flexion, delayed knee flexion

Question 45

suspension causing knee flexion

Answer 45

excessive knee flexion, early knee flexion

Question 46

socket with insufficient flexion

Answer 46

insufficient knee flexion, delayed knee flexion

Question 47

socket with excessive flexion

Answer 47

excessive knee flexion, early knee flexion

Question 48

socket posterior to foot

Answer 48

insufficient knee flexion, delayed knee flexion

Question 49

socket anterior to foot

Answer 49

excessive knee flexion, early knee flexion

Question 50

socket in excessive adduction

Answer 50

excessive lateral thrust

Question 51

socket in abduction

Answer 51

medial thrust = pain at fibular head

Question 52

heel cushion too resilient

Answer 52

insufficient knee flexion,

Question 53

heel cushion too firm

Answer 53

excessive knee flexion,

Question 54

foot in PF

Answer 54

insufficient knee flexion, delayed knee flexion

Question 55

foot in DF

Answer 55

excessive knee flexion, early knee flexion

Question 56

foot excessively outset

Answer 56

medial thrust (same as excessive ABD)

Question 57

foot excessively inset

Answer 57

excessive lateral thrust (same as excessive ADD)

Question 58

shoe heel lower

Answer 58

iinsufficient knee flexion,

Question 59

shoe heel higher

Answer 59

excessive knee flexion

Question 60

prosthesis too long

Answer 60

excessive knee flexion; long prosthetic step

Question 61

prosthesis too short

Answer 61

insufficient knee flexion