CO Orthotic Assessment, Prescription & Device Design 2

Question 1

During a static stance assessment, a patient shows excessive subtalar pronation with forefoot varus. Which orthotic feature most directly addresses this compensation pattern?

Accepted Answer

Medial heel post with forefoot varus posting

Answer

A medial heel post controls rearfoot eversion and a forefoot varus post compensates for the intrinsic forefoot varus deformity, reducing the need for subtalar pronation.

Question 2

A 55-year-old diabetic patient presents with a grade 2 plantar ulcer at the first metatarsal head. Which orthotic design principle is the primary goal of pressure redistribution?

Accepted Answer

Total contact casting principles applied to an insole to distribute plantar pressure evenly

Answer

Total contact design maximizes the plantar surface area bearing load, thereby minimizing peak pressure at any single site such as the ulcerated metatarsal head.

Question 3

When prescribing a KAFO for a patient with quadriceps weakness and intact hamstrings, which knee joint design best accommodates functional ambulation while providing extension stability?

Accepted Answer

Offset knee joint set posterior to the anatomical knee axis

Answer

An offset (posterior) knee joint places the mechanical axis behind the anatomical axis, creating a knee extension moment under load that compensates for quadriceps weakness without requiring a locked joint.

Question 4

A practitioner measures a patient's subtalar joint neutral position as 4° varus. The forefoot-to-rearfoot relationship measured with the subtalar joint in neutral is 3° valgus. What is the clinical implication for orthotic posting?

Accepted Answer

Post the rearfoot only in neutral since forefoot valgus partially compensates

Answer

The rearfoot varus (4°) exceeds the compensating forefoot valgus (3°), so rearfoot posting to neutral is indicated while recognizing that forefoot posting requirements are reduced.

Question 5

Which gait-cycle event primarily triggers the need for an ankle-foot orthosis with a dorsiflexion assist feature in a patient with isolated tibialis anterior weakness?

Accepted Answer

Mid-swing — foot drop causing toe drag

Answer

Tibialis anterior weakness causes foot drop during swing phase, leading to toe drag; a dorsiflexion assist spring or elastic posterior leaf spring raises the foot to clear the ground.

(CO) Certified Orthotics Specialist Practice Test

(CO) Certified Orthotics Specialist Practice Test

CO Orthotic Assessment, Prescription & Device Design 2