OCC Casting Materials & Techniques 3

Question 1

When molding a cast, which technique is recommended to avoid creating pressure points?

Accepted Answer

Using the palm and thenar eminence to apply broad, even pressure

Answer

Broad palm and thenar eminence molding distributes pressure evenly, preventing focal pressure points that can cause skin breakdown.

Question 2

A fiberglass cast becomes warm during setting. This heat is primarily due to which process?

Accepted Answer

An exothermic polyurethane curing reaction

Answer

Fiberglass tape contains a polyurethane prepolymer that undergoes an exothermic curing reaction when activated by water, generating heat.

Question 3

Which of the following best describes 'bivalving' a cast?

Accepted Answer

Cutting the cast longitudinally on two sides to create two halves

Answer

Bivalving involves making two longitudinal cuts on opposite sides of the cast, converting it into two clamshell-like halves to relieve pressure.

Question 4

For a long leg cast, the knee is typically immobilized in how many degrees of flexion?

Accepted Answer

20–30 degrees of flexion

Answer

A long leg cast is typically applied with 20–30 degrees of knee flexion to provide stability while allowing the patient to bear weight comfortably.

Question 5

Which casting material generally has the HIGHEST tensile strength per unit weight?

Accepted Answer

Fiberglass (polyurethane-impregnated glass fiber)

Answer

Fiberglass casting tape provides superior tensile strength at a lighter weight compared to plaster, which is why it requires fewer layers for equivalent support.

(OCC) Orthopedic Casting Certification Practice Test

(OCC) Orthopedic Casting Certification Practice Test

OCC Casting Materials & Techniques 3