LE Oral Questions

Question 1

How do you determine stirrup length?

Answer 1

2 x height of distal tip of medial malleolus + width of heel + 6 mm

Question 2

How do you determine band length?

Answer 2

1/2 circumference + 1.5”

Question 3

What are the minimum clearances for ankle joints and knee joints?

Answer 3

Ankle: 6mm medial/5mm lateral
Knee: 6mm medial/3mm lateral

Question 4

In a conventional KAFO what changes could you use to reduce recurvatum?

Answer 4

Shallow bands
Move calf band up and distal thigh down (move closer)
Increase heel height

Question 5

What problems could you encounter in moving the bands of a KAFO?

Answer 5

Peroneal nerve impingement

Limited knee flexion

Question 6

How much PF would you allow a patient who has suffered a CVA?

Answer 6

Neutral

Question 7

How do you determine if a patient requires locks on his KAFO vs free knee?

Answer 7

Hip/knee extensor weakness

Question 8

What do you recommend for a patient who exhibits foot slap at heel strike?

Answer 8

AFO with PF stop

Question 9

What is Legg-Calve-Perthes disease?

Answer 9

Avascular necrosis of the femoral head
Usually boys 9-14
Femoral head will return to normal if the leg is abducted and internally rotated

Question 10

Name 3 orthoses used for LCP.

Answer 10

Scottish Rite
Toronto
Newington

Question 11

Name 3 orthoses for the treatment of hip dysplasia.

Answer 11

Pavlik
Rhino
Ilfeld Splint
Frejka pillow

Question 12

What is tibial torsion?

Answer 12

Difference between knee and ankle joint axes as viewed in the transverse plane

Question 13

How is tibial torsion measured?

Answer 13

KF 90*

Measure apex of each malleolus to a surface behind the leg

Question 14

What types of functional devices can be used for excessive pronation of the foot?

Answer 14

FO

UCBL

Question 15

A UCBL is used for more control of what part of the foot?

Answer 15

hindfoot

subtalar joint

Question 16

What is the cause of Charcot joints in the feet/ankle?

Answer 16

Any neuropathic disease can have Charcot joints

diabetes, herpes, syphilis

Question 17

Evaluation of a patient with a gunshot wound to the hip reveals weak hip flexors. What peripheral nerve is injured?

Answer 17

femoral N.

Question 18

What is your orthotic recommendation for pt w/ weak hip flexors?

Answer 18

cane on contralateral side?

Question 19

Describe chondromalacia.

Answer 19

softness of the articular cartilage usually involving the patellofemoral joint

Question 20

What is your orthotic recommendation for chondromalacia?

Answer 20

Palumbo orthosis or other patellar stabilizing orthosis

Question 21

A patient’s KAFO has free motion knee, but the mechanical joint is 1” distal to the anatomical joint. In flexion, the resulting pressures will be…

Answer 21

Proximal posterior thigh
Distal anterior thigh
Orthosis migrates proximally

Question 22

Toe drag is a bigger problem in what phase of gait? Why?

Answer 22

Initial swing - if the toe does not clear the floor, the patient takes short steps and may trip

Question 23

Why do diabetics get foot ulcers?

Answer 23

loss of sensation

Question 24

What is the advantage of an offset knee joint for treating recurvatum?

Answer 24

puts the weight bearing line anterior to the knee joint, making it unnecessary to lock the knee

Question 25

Describe Guillain-Barre and its effects on the patient.

Answer 25

infectious polyneuritis with progressive muscular weakness, distal to proximal, may lead to paralysis prognosis usually full recovery

Question 26

Describe Charcot-Marie-Tooth.

Answer 26

inherited progressive neuromuscular atrophy characterized by progressive weakness of the distal muscles of arms and feet usually develops in childhood

Question 27

When would you recommend a bail lock on a KAFO instead of drop locks?

Answer 27

only one functional hand | When canes/crutches are used with bilateral KAFOs

Question 28

Name two contraindications for plastic AFOs.

Answer 28

uncontrolled edema | sensitive skin

Question 29

Name two methods of minimizing knee flexion torque at initial contact in a lower extremity orthosis.

Answer 29

beveled heel undercut heel SACH heel

Question 30

What implications do weak hip flexors have in your design of a KAFO?

Answer 30

a lightweight design could encourage hip flexion at swing phase

Question 31

For which diagnoses would you recommend a rocker bottom shoe?

Answer 31

diabetes arthritis ankle fusion

Question 32

What is the rx rationale for a rocker bottom shoe?

Answer 32

simulate normal foot biomechanics and promote even wt bearing distribution in a pt w/ limited or no ankle motion

Question 33

A polio patient has a flail ankle, good knee muscles, good hip muscles, and full ROM at knee w/ recurvatum of 25*. Knee buckles when tired. What orthosis do you recommend? Describe the mechanical principles.

Answer 33

Lightweight KAFO, offset or drop lock knee, solid plastic AFO section w/ rocker bottom shoe or a DAAJ. Solid ankle for AFO section

Question 34

Six weeks post ACL repair, how do you cast? What two mechanical principles do you want?

Answer 34

cast in slight flexion | prevent hyperextension and control rotation

Question 35

Name 2 reasons why you might not use pretibial AFOs for a patient who walks w/ crouch gait.

Answer 35

hip flexion contracture lack of ankle ROM inability to don

Question 36

Give 4 contraindications for RGOs.

Answer 36

``` obesity hip flexion contracture >20* spasticity non-plantigrade foot hip dislocation ```

Question 37

Name 3 clinical signs of charcot joints at ankle mortise.

Answer 37

``` swelling instability excessive joint mobility pain anesthetic foot visual deformity ```

Question 38

Name 3 mechanical principles for treatment of Charcot joints.

Answer 38

immobilize in total contact AFO minimal weight bearing rocker bottom

Question 39

Name 3 signs in evaluation of heel spur pain

Answer 39

valgus foot pes planus localized pain at loading

Question 40

Name 2 mechanical principles for treating heel spurs.

Answer 40

distribute and reduce pressure in arch support | UBC for hindfoot and/or forefoot control

Question 41

Where should you place the mechanical hip joint?

Answer 41

1/2" anterior and 1" superior to GT

Question 42

How would elevating the shoe heel affect a solid ankle AFO?

Answer 42

increased KFM at heel strike

Question 43

What effect would posterior placement of knee joints have on a KAFO?

Answer 43

migrates proximally with pressure on anterior calf cuff

Question 44

What modifications can you make to a plastic KAFO to reduce recurvatum?

Answer 44

trim proximal and distal sections closer to the knee pad shells shallow shells

Question 45

Why would you choose a metal AFO over plastic for a patient with Charcot joints?

Answer 45

prevent skin breakdown due to insensate foot

Question 46

What are the stance phases of gait and what is the hip position through each?

Answer 46

``` IC: 30* flexion LR: 25-30* flexion Midstance: 20* flexion to 5* extension Heel off: 10* extension Push off: 10* extension ```

Question 47

How can you prevent a knee orthosis from migrating down?

Answer 47

supracondylar wedge suprapatellar strap attach to foot plate lightweight belt