CFO Orthotic Device Design & Fabrication 3

Question 1

A wrist-hand orthosis (WHO) intended to immobilize the wrist in neutral should position the wrist at approximately:

Accepted Answer

0–10° extension

Answer

A functional or resting WHO is typically fabricated with the wrist in neutral to slight extension (0–10°) to maintain a functional hand position and prevent contracture.

Question 2

When selecting polypropylene sheet thickness for a pediatric foot orthosis for a child weighing 20 kg, the fitter should choose:

Accepted Answer

3/16 inch (4.8 mm)

Answer

A 3/16-inch (4.8 mm) polypropylene sheet provides adequate rigidity for a child around 20 kg without being unnecessarily heavy or stiff.

Question 3

The 'University of California Biomechanics Laboratory' (UCBL) insert is designed primarily to control:

Accepted Answer

Subtalar valgus and hindfoot pronation

Answer

The UCBL insert features deep heel cup walls that capture the calcaneus and control excessive subtalar eversion (hindfoot valgus/pronation).

Question 4

A fitter is using a heat gun to spot-heat a thermoplastic orthosis for minor adjustments. At what distance should the heat gun be held to avoid burning the material?

Accepted Answer

6–8 inches (15–20 cm)

Answer

Holding the heat gun 6–8 inches away concentrates heat enough to soften a small area without scorching or distorting adjacent material.

Question 5

Which edge-finishing technique BEST reduces the risk of skin abrasion along the proximal trim line of a hard plastic AFO?

Accepted Answer

Flaring and flame-polishing the edge

Answer

Flaring the proximal edge outward and then flame- or belt-polishing it removes sharp burrs and creates a smooth, rolled edge that is less likely to abrade the skin.

(CFO) Certified Fitter Orthotics Practice Test

(CFO) Certified Fitter Orthotics Practice Test

CFO Orthotic Device Design & Fabrication 3