CO Orthotic Assessment, Prescription & Device Design 3

Question 1

A practitioner is designing a cervical orthosis for a C5–C6 fracture that requires strict motion restriction in all planes. Which orthosis provides the highest level of cervical immobilization?

Accepted Answer

Halo vest orthosis

Answer

The halo vest provides the greatest restriction of cervical motion in all planes by rigidly attaching to the skull via pins and to the thorax via a vest.

Question 2

During orthotic gait analysis, a patient with an AFO demonstrates a forward trunk lean during mid-stance. Which orthotic modification is most likely to correct this compensatory movement?

Accepted Answer

Reduce AFO dorsiflexion resistance to allow more forward tibial progression

Answer

Excessive resistance to dorsiflexion prevents forward tibial progression, forcing the trunk to lean forward to advance the center of mass; reducing resistance restores normal sagittal kinematics.

Question 3

When selecting shell material for a custom spinal orthosis for a heavy laborer requiring lumbar support during lifting, which material property is most critical?

Accepted Answer

High elastic modulus to resist deformation under cyclic load

Answer

A high elastic modulus (stiffness) ensures the orthotic shell maintains its shape and provides consistent support rather than deforming under repeated heavy loads.

Question 4

A patient with rheumatoid arthritis has MCP joint subluxation with ulnar drift. A resting hand orthosis is prescribed. What is the primary design goal?

Accepted Answer

Immobilize the wrist in slight extension and position MCP joints in neutral alignment to reduce deforming forces

Answer

A resting hand orthosis positions the wrist in slight extension and MCP/IP joints near neutral to relieve pain, reduce inflammation, and counteract the ulnar deforming forces.

Question 5

The neutral calcaneal stance position (NCSP) differs from the relaxed calcaneal stance position (RCSP) in that NCSP:

Accepted Answer

Measures the calcaneal angle with the subtalar joint positioned in neutral, typically showing less valgus than RCSP

Answer

NCSP is measured with the subtalar joint in neutral, so it typically shows a less everted (or even inverted) calcaneus compared to RCSP which reflects the weight-bearing pronated position.

(CO) Certified Orthotics Specialist Practice Test

(CO) Certified Orthotics Specialist Practice Test

CO Orthotic Assessment, Prescription & Device Design 3