ABC ORTHOTICS & PROSTHETICS WRITTEN/CLINICAL EXAM
READY - VERIFIED QUESTIONS AND ANSWERS -
COMPREHENSIVE LATEST VERSION
1. Q: What is the primary function of a solid ankle AFO? ANSWER To
provide maximum stability by preventing all ankle motion in dorsiflexion,
plantarflexion, inversion, and eversion.
2. Q: What condition is most appropriately treated with a posterior leaf
spring AFO? ANSWER Foot drop due to weak dorsiflexors (common
peroneal nerve palsy or L5 radiculopathy).
3. Q: What is the trim line location for a solid ankle AFO? ANSWER
Anterior to the malleoli, typically at the midline of the tibia.
4. Q: What material property is most important for a posterior leaf spring
AFO? ANSWER Flexibility and spring-like return to provide dorsiflexion
assist during swing phase.
5. Q: What is the primary indication for a ground reaction AFO
(GRAFO)? ANSWER Knee instability in stance phase, particularly knee
hyperextension or excessive knee flexion (crouch gait).
6. Q: How does a ground reaction AFO control the knee? ANSWER By
positioning the ankle in slight dorsiflexion and using a rigid anterior shell to
create a knee extension moment through ground reaction forces.
7. Q: What is the primary difference between a solid ankle AFO and an
articulated AFO? ANSWER An articulated AFO has a mechanical ankle
joint allowing controlled motion, while a solid ankle AFO prevents all ankle
motion.
8. Q: What is the ideal heel height for a patient wearing a solid ankle AFO?
ANSWER The same heel height used during casting/measurement to maintain
proper ankle position.
9. Q: What gait deviation would you expect from an AFO set in excessive
plantarflexion? ANSWER Knee hyperextension during stance phase and
difficulty advancing the tibia over the foot.
,10. Q: What is the Rancho Los Amigos terminology for an AFO that limits
plantarflexion only? ANSWER A floor reaction AFO or plantarflexion stop
AFO.
11. Q: What muscle weakness is indicated when a patient requires
medial/lateral ankle stability? ANSWER Weakness of the ankle invertors
(tibialis posterior) and/or evertors (peroneals).
12. Q: What is the primary advantage of a carbon fiber AFO over
polypropylene? ANSWER Greater strength-to-weight ratio, allowing thinner
construction with better cosmesis and energy return.
13. Q: At what point in the gait cycle does a posterior leaf spring AFO
provide assistance? ANSWER During swing phase (toe-off to heel strike) to
assist with foot clearance.
14. Q: What is the correct strap placement for a solid ankle AFO?
ANSWER One strap across the instep/forefoot and one around the proximal
calf, just below the fibular head.
15. Q: What nerve injury commonly requires an AFO for foot drop?
ANSWER Common peroneal (fibular) nerve injury.
Knee-Ankle-Foot Orthoses (KAFOs)
16. Q: What is the primary indication for a KAFO? ANSWER Knee
instability due to quadriceps weakness, ligamentous instability, or combined
knee and ankle weakness.
17. Q: What type of knee joint allows the patient to lock the knee in
extension for standing? ANSWER A drop lock, bail lock, or pawl lock with
manual release.
18. Q: What is a stance control KAFO? ANSWER A KAFO with a knee
joint that automatically locks during stance phase and unlocks during swing
phase.
19. Q: What muscles must be functional for a patient to successfully use a
KAFO with free knee joints? ANSWER Hip flexors, hip extensors, and hip
abductors must be at least 4/5 strength.
20. Q: What is the primary disadvantage of a KAFO with locked knees?
ANSWER High energy expenditure, unnatural gait pattern, and difficulty with
stairs and sitting.
, 21. Q: What is the Scott-Craig KAFO designed for? ANSWER Ambulation
in patients with complete thoracic-level spinal cord injury using a swing-
through gait pattern.
22. Q: What key features does a Scott-Craig KAFO include? ANSWER
Locked knee joints, offset knee joints, bail locks, ankle in slight dorsiflexion,
cushioned heel, and a rigid sole plate.
23. Q: What is the purpose of offset knee joints in a KAFO? ANSWER To
position the mechanical knee joint posterior to the anatomical knee joint,
creating a knee extension moment during stance.
24. Q: What is the primary indication for a KAFO with free motion knee
joints? ANSWER Medial/lateral knee instability with adequate quadriceps
strength (at least 4/5).
25. Q: What gait pattern is typically used with bilateral KAFOs and locked
knees? ANSWER Swing-to or swing-through gait pattern using forearm
crutches or a walker.
26. Q: What is a Swedish knee cage? ANSWER A three-point pressure
system KAFO used primarily for recurvatum control with medial/lateral knee
stability.
27. Q: Where should the mechanical knee joint axis be positioned?
ANSWER Aligned with the anatomical knee joint axis, approximately 1.5 cm
above the medial tibial plateau.
28. Q: What is the advantage of a polycentric knee joint in a KAFO?
ANSWER Better tracking of the anatomical knee motion and reduced pistoning
in the orthosis.
29. Q: What is a common complication of a poorly fitted proximal thigh
band? ANSWER Pressure on the peroneal nerve at the fibular head, causing
foot drop.
30. Q: What is the primary energy cost difference between AFO and
KAFO use? ANSWER KAFO use requires significantly higher energy
expenditure (25-40% increase) compared to AFO use.
Hip-Knee-Ankle-Foot Orthoses (HKAFOs) & Reciprocating Gait Orthoses
(RGOs)
31. Q: What is the primary indication for an HKAFO? ANSWER Hip
instability combined with knee and ankle weakness, typically in high-level
spinal cord injury or extensive paralysis.
READY - VERIFIED QUESTIONS AND ANSWERS -
COMPREHENSIVE LATEST VERSION
1. Q: What is the primary function of a solid ankle AFO? ANSWER To
provide maximum stability by preventing all ankle motion in dorsiflexion,
plantarflexion, inversion, and eversion.
2. Q: What condition is most appropriately treated with a posterior leaf
spring AFO? ANSWER Foot drop due to weak dorsiflexors (common
peroneal nerve palsy or L5 radiculopathy).
3. Q: What is the trim line location for a solid ankle AFO? ANSWER
Anterior to the malleoli, typically at the midline of the tibia.
4. Q: What material property is most important for a posterior leaf spring
AFO? ANSWER Flexibility and spring-like return to provide dorsiflexion
assist during swing phase.
5. Q: What is the primary indication for a ground reaction AFO
(GRAFO)? ANSWER Knee instability in stance phase, particularly knee
hyperextension or excessive knee flexion (crouch gait).
6. Q: How does a ground reaction AFO control the knee? ANSWER By
positioning the ankle in slight dorsiflexion and using a rigid anterior shell to
create a knee extension moment through ground reaction forces.
7. Q: What is the primary difference between a solid ankle AFO and an
articulated AFO? ANSWER An articulated AFO has a mechanical ankle
joint allowing controlled motion, while a solid ankle AFO prevents all ankle
motion.
8. Q: What is the ideal heel height for a patient wearing a solid ankle AFO?
ANSWER The same heel height used during casting/measurement to maintain
proper ankle position.
9. Q: What gait deviation would you expect from an AFO set in excessive
plantarflexion? ANSWER Knee hyperextension during stance phase and
difficulty advancing the tibia over the foot.
,10. Q: What is the Rancho Los Amigos terminology for an AFO that limits
plantarflexion only? ANSWER A floor reaction AFO or plantarflexion stop
AFO.
11. Q: What muscle weakness is indicated when a patient requires
medial/lateral ankle stability? ANSWER Weakness of the ankle invertors
(tibialis posterior) and/or evertors (peroneals).
12. Q: What is the primary advantage of a carbon fiber AFO over
polypropylene? ANSWER Greater strength-to-weight ratio, allowing thinner
construction with better cosmesis and energy return.
13. Q: At what point in the gait cycle does a posterior leaf spring AFO
provide assistance? ANSWER During swing phase (toe-off to heel strike) to
assist with foot clearance.
14. Q: What is the correct strap placement for a solid ankle AFO?
ANSWER One strap across the instep/forefoot and one around the proximal
calf, just below the fibular head.
15. Q: What nerve injury commonly requires an AFO for foot drop?
ANSWER Common peroneal (fibular) nerve injury.
Knee-Ankle-Foot Orthoses (KAFOs)
16. Q: What is the primary indication for a KAFO? ANSWER Knee
instability due to quadriceps weakness, ligamentous instability, or combined
knee and ankle weakness.
17. Q: What type of knee joint allows the patient to lock the knee in
extension for standing? ANSWER A drop lock, bail lock, or pawl lock with
manual release.
18. Q: What is a stance control KAFO? ANSWER A KAFO with a knee
joint that automatically locks during stance phase and unlocks during swing
phase.
19. Q: What muscles must be functional for a patient to successfully use a
KAFO with free knee joints? ANSWER Hip flexors, hip extensors, and hip
abductors must be at least 4/5 strength.
20. Q: What is the primary disadvantage of a KAFO with locked knees?
ANSWER High energy expenditure, unnatural gait pattern, and difficulty with
stairs and sitting.
, 21. Q: What is the Scott-Craig KAFO designed for? ANSWER Ambulation
in patients with complete thoracic-level spinal cord injury using a swing-
through gait pattern.
22. Q: What key features does a Scott-Craig KAFO include? ANSWER
Locked knee joints, offset knee joints, bail locks, ankle in slight dorsiflexion,
cushioned heel, and a rigid sole plate.
23. Q: What is the purpose of offset knee joints in a KAFO? ANSWER To
position the mechanical knee joint posterior to the anatomical knee joint,
creating a knee extension moment during stance.
24. Q: What is the primary indication for a KAFO with free motion knee
joints? ANSWER Medial/lateral knee instability with adequate quadriceps
strength (at least 4/5).
25. Q: What gait pattern is typically used with bilateral KAFOs and locked
knees? ANSWER Swing-to or swing-through gait pattern using forearm
crutches or a walker.
26. Q: What is a Swedish knee cage? ANSWER A three-point pressure
system KAFO used primarily for recurvatum control with medial/lateral knee
stability.
27. Q: Where should the mechanical knee joint axis be positioned?
ANSWER Aligned with the anatomical knee joint axis, approximately 1.5 cm
above the medial tibial plateau.
28. Q: What is the advantage of a polycentric knee joint in a KAFO?
ANSWER Better tracking of the anatomical knee motion and reduced pistoning
in the orthosis.
29. Q: What is a common complication of a poorly fitted proximal thigh
band? ANSWER Pressure on the peroneal nerve at the fibular head, causing
foot drop.
30. Q: What is the primary energy cost difference between AFO and
KAFO use? ANSWER KAFO use requires significantly higher energy
expenditure (25-40% increase) compared to AFO use.
Hip-Knee-Ankle-Foot Orthoses (HKAFOs) & Reciprocating Gait Orthoses
(RGOs)
31. Q: What is the primary indication for an HKAFO? ANSWER Hip
instability combined with knee and ankle weakness, typically in high-level
spinal cord injury or extensive paralysis.
