CTO CTO Lower Extremity Orthotics 2 — Questions and Answers
Question 1: What is the function of a plantar fascia groove in a custom foot orthosis?
- Increase cushioning under the heel
- Accommodate the plantar fascia to reduce compression and irritation (Correct answer)
- Improve torsional rigidity
- Control first ray motion
Correct answer: Accommodate the plantar fascia to reduce compression and irritation
A plantar fascia groove is a relief cut in the orthotic shell that accommodates the plantar fascia band to reduce localized pressure and irritation.
Question 2: Which design feature distinguishes a floor-reaction AFO from a standard posterior AFO?
- It is made of softer materials
- It has an anterior tibial shell that creates a knee extension moment via ground reaction forces (Correct answer)
- It only covers the foot
- It has an articulated ankle joint
Correct answer: It has an anterior tibial shell that creates a knee extension moment via ground reaction forces
A floor-reaction AFO uses an anterior tibial shell to transmit ground reaction forces and create a knee extension moment, benefiting patients with weak quadriceps.
Question 3: What is the recommended trim line position for a standard posterior leaf spring (PLS) AFO to allow some mediolateral flexibility?
- Anterior to the malleoli
- Posterior to the malleoli
- At the level of the malleoli (Correct answer)
- Above the malleoli
Correct answer: At the level of the malleoli
Trimming the PLS AFO at the level of the malleoli provides some mediolateral flexibility while still controlling dorsiflexion and plantarflexion.
Question 4: What is the primary indication for a hip-knee-ankle-foot orthosis (HKAFO)?
- Isolated ankle drop
- Hip dysplasia in adults
- Bilateral lower extremity paralysis requiring hip and trunk stabilization for ambulation (Correct answer)
- Unilateral knee pain
Correct answer: Bilateral lower extremity paralysis requiring hip and trunk stabilization for ambulation
An HKAFO is indicated for bilateral lower extremity paralysis where the patient requires hip stabilization and trunk support in addition to knee and ankle control to ambulate.
Question 5: What is the significance of the proximal brim height of an AFO?
- It determines shoe size
- It affects the lever arm length and therefore the orthosis's ability to control ankle and knee moments (Correct answer)
- It only affects cosmesis
- It determines how much the device weighs
Correct answer: It affects the lever arm length and therefore the orthosis's ability to control ankle and knee moments
The proximal brim height determines the length of the lever arm, which directly affects the orthosis's mechanical advantage in controlling ankle moments and influencing knee stability.
Question 6: Which type of AFO is most appropriate for a patient with mild foot drop who needs dorsiflexion assistance but has good mediolateral stability?
- Solid ankle AFO
- Ground reaction AFO
- Posterior leaf spring AFO (Correct answer)
- KAFO with drop lock
Correct answer: Posterior leaf spring AFO
A posterior leaf spring AFO is ideal for mild foot drop with preserved mediolateral stability because its flexible design provides dorsiflexion assist while allowing some ankle motion.
CTO CTO Lower Extremity Orthotics 2
What is the function of a plantar fascia groove in a custom foot orthosis?