COC Orthotic and Prosthetic Design & Fabrication 5

Question 1

In a Jewett hyperextension orthosis, the posterior force of the three-point system is applied at the:

Accepted Answer

Thoracolumbar junction

Answer

Sternal and pubic pads push posteriorly while the thoracolumbar pad pushes anteriorly to create extension.

Question 2

Moving the trimlines of a solid AFO anterior to the malleoli will:

Accepted Answer

Increase resistance to ankle motion

Answer

Anterior trimlines increase the cross-sectional stiffness of the plastic at the ankle.

Question 3

A ground reaction (floor reaction) AFO is most appropriate for a patient with:

Accepted Answer

Crouch gait due to weak plantarflexors or quadriceps

Answer

The anterior shell creates a knee extension moment to counter excessive stance knee flexion.

Question 4

A plantarflexion stop on an AFO produces what effect at initial contact?

Accepted Answer

Knee flexion moment

Answer

Blocking plantarflexion moves the tibia forward at loading, creating a knee flexion moment.

Question 5

An offset knee joint on a KAFO improves stance stability because the mechanical axis is placed:

Accepted Answer

Posterior to the anatomical knee axis

Answer

A posterior offset keeps the weight line anterior to the joint, extending the knee in stance.

COC - Certified Orthotic and Prosthetic Practitioner Practice Test