COC Orthotic and Prosthetic Design & Fabrication 2

Question 1

Which thermoplastic is most commonly chosen for custom AFOs because of its fatigue resistance and moldability?

Accepted Answer

Polypropylene

Answer

Polypropylene resists repeated flexing without cracking, making it the standard AFO material.

Question 2

Compared with homopolymer polypropylene, copolymer polypropylene (with added ethylene) is:

Accepted Answer

More flexible and more impact resistant

Answer

Ethylene content increases flexibility and toughness while reducing stiffness.

Question 3

The main reason carbon fiber is added to a laminated prosthetic socket is to provide:

Accepted Answer

High stiffness with low weight

Answer

Carbon fiber offers an excellent stiffness-to-weight ratio for structural reinforcement.

Question 4

Which reinforcement fabric is known for high tensile and impact strength but is very difficult to cut and sand?

Accepted Answer

Kevlar (aramid)

Answer

Aramid fibers are extremely tough, which makes trimming and finishing laminations difficult.

Question 5

Increasing the ratio of flexible to rigid acrylic resin in a lamination will result in a laminate that is:

Accepted Answer

More flexible and less rigid

Answer

Flexible resin increases compliance of the finished laminate.

COC - Certified Orthotic and Prosthetic Practitioner Practice Test