Plastic AFO

Question 1

To determine the proper AP heel placement on a footboard

Answer 1

Place the shoe to be worn along side of the foot board and mark on the footboard where the heel will be situated in the shoe

Question 2

Which of the following body landmarks should be marked when taking an AFO impression?

Answer 2

Both malleoli
The base of the fifth 
The head of the fifth 
The head of the first 
Neck of fibula and 
Navicular

Question 3

What linear measurements are required to fabricate a plastic AFO?

Answer 3

The ML diameter at the Apices of the malleoli and the height of the fibular neck.

Question 4

In general, the desired position of the subtalar joint in a plastic AFO is?

Answer 4

Neutral

Question 5

Stockinette is used when taking an impression for an AFO?

Answer 5

To protect the patient and provide a separator for pouring plaster

Question 6

The goal of a proper plastic impression on the plantar aspect of the foot is?

Answer 6

To provide a smooth, uniform surface

Question 7

To prevent inadvertent deformation of the plantar aspect of the impression, it is recommended that?

Answer 7

A separator be used such as the plaster bandage wrapper

Question 8

A smooth, conforming impression can be obtained by?

Answer 8

Using a layer of elastic plaster bandage first

Question 9

When using an oscillating cast saw for removal of an impression the proper technique involves

Answer 9

Alternating an advancing up and down motions

Question 10

Cast modifications for plastic AFO includes removal of material from the heel medically and laterally in order to?

Answer 10

Provide a good gasp of the calcaneus

Question 11

The plantar surface of the cast is flattened at the heel and forefoot to?

Answer 11

Ensure joint neutrality and provide a stable base of support

Question 12

Unless otherwise indicated, the cast build-up for the malleoli

Answer 12

Is 3/16 inch (5mm) laterally and 1/4 inch (6mm) medially

Question 13

Which of the following bony prominences should be built up on a cast a polypropylene AFO?

Answer 13

Base of the 5th
Navicular
Malleoli
And tendon calcaneus

Question 14

The distal trim line on the plantar surface of a plastic AFO is?

Answer 14

Toe crease, distal tip of the toes, or proximal to the met heads

Question 15

The minimal clearance between the proximal edge of a plastic and the neck of the fibula is

Answer 15

20mm

Question 16

To ensure uniform vacuum forming during fabrication of the plastic AFO it Is sometimes helpful to

Answer 16

Carve A groove in the cast and use thin nylon stocking

Question 17

The appropriate temperature for vacuum for polypropylene is?

Answer 17

20 gdghdnsn

Question 18

To minimize expansion and contraction warping of a polypropylene AFO, it should be left on the cast and not removed for?

Answer 18

16 hours

Question 19

Progressive posterior trimming of a plastic AFO about the malleoli will

Answer 19

Increase flexibility in all planes

Question 20

What is the main reason scratches and sharp corners are avoided when finishing a plastic AFO

Answer 20

To avoid creating stress risers which could cause premature failure

Question 21

Symmetrical trim lines about the ankle are important in

Answer 21

Preventing twisting of the AFO about the long axis in stance

Question 22

The anterior closure of a plastic AFO is frequently comprised of a strap with Velcro wrapped back onto itself through a chafe in order to?

Answer 22

Reduce the shear force on the closure by 50%

Question 23

if two rivets are used to fasten one end of a strap on an AFO, before attaching the second rivet it is necessary to?

Answer 23

Establish the correct angle of the strap

Question 24

When a plastic AFO is on the patient along with the shoe, what portions of the patients leg and foot receive forces as the patient attempts to plantar-flex his ankle joint?

Answer 24

Posterior -proximal leg and dista, plantar aspect

Question 25

When a plastic AFO is on the patient along with the shoe what portions of the patients leg and foot receive force as the patient attempts to dorsiflex his ankle joint?

Answer 25

Anterior proximal and anterior distal

Question 26

What areas of the patients foot receives pressure when a patient wearing a plastic AFO tries to invert his subtalar axis?

Answer 26

Medial foot, medial proximal calf, and area proximal to lateral malleolus

Question 27

What areas of the patients foot receives pressure when a patient wearing a plastic AFO tries to evert his subtalar axis?

Answer 27

Lateral foot, lateral proximal calf, and areas proximal to medial malleolus

Question 28

What component can be added to a plastic AFO to increase resistance to plantarflexion?

Answer 28

A dorsal strap near the malleoli

Question 29

The best technique for increasing the rigidity of a plastic AFO without significantly increasing weight or bulk is to?

Answer 29

Incorporate crescent shaped carbon composite inserts in the area of the malleoli

Question 30

Why is a plastic AFOs proximal trim line adjusted so that it is 3/4” (20mm) from the neck of the fibula?

Answer 30

To avoid pressure on the Peroneal nerve and to obtain maximum bio mechanical leverage

Question 31

What insert modification can be employed to reduce toe clawing?

Answer 31

A metatarsal pad

Question 32

If a plastic AFO is made sufficiently flexible to allow controlled plantar flexion what is it good idea to trim the proximal edge more than normal amount?

Answer 32

To allow for proximal motion of the calf shell during plantar flexion adjacent to the Peroneal nerve.

Question 33

What is likely consequences of placing a lower than anticipated heel height on a rigid polypropylene AFO?

Answer 33

Knee hyperextension

Question 34

What is a likely consequence of placing a higher than anticipated heel height on a rigid polypropylene AFO?

Answer 34

Knee flexion

Question 35

Why might it be a good idea to fabricate a plastic AFO in plantar flexion?

Answer 35

To reduce knee flexion thrust at loading

Question 36

Why might it be a good idea to fabricate a plastic AFO in dorsiflexion?

Answer 36

To reduce knee extension thrust at loading

Question 37

Two acceptable techniques for relieving pressure at a specific location on plastic AFO are?

Answer 37

Relieve the area by heating and creating a pocket or increase pressure surrounding the area

Question 38

A foot board is used when taking an impression for a plastic AFO in order?

Answer 38

To duplicate the heel to sole height difference in the shoe to be worn