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ABC Certified Prosthetist/Orthotist (CPO) Written
Exam | Latest Verified Questions and Detailed
Answers
OVERVIEW DESCRIPTION:
This Comprehensive set of multiple choice questions is designed for the ABC Certified
Prosthetist/Orthotist (CPO) Written Exam, a computer-based testing (CBT) assessment
administered by the American Board for Certification in Orthotics, Prosthetics & Pedorthics
(ABC). The exam uses multiple-choice questions with four answer choices each and may
capitalize or bold key terms in question stems to focus attention. It evaluates general
knowledge of patient management and foundational sciences across both orthotics and
prosthetics, with content distributed across foundational sciences; patient assessment and
evaluation, including history taking, physical exam, manual muscle testing, range of motion,
skin integrity, gait analysis, and cognitive/functional screening; formulation and
implementation of treatment plans, including prescription criteria, device recommendation
and design, componentry, material selection, and fabrication principles; follow-up and
clinical management, including device fit and alignment, patient complications, ongoing
maintenance, and outcome measurement; and professional practice, including safety
standards, healthcare documentation, insurance necessity, and ethical/professional
compliance.
QUESTION 1
A Trendelenburg gait occurs with weakness of which muscle?
A. Gluteus medius
B. Gluteus maximus
C. Adductor magnus
D. Rectus femoris
CORRECT ANSWER: A. Gluteus medius
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EXPERT RATIONALE: The gluteus medius prevents contralateral pelvic drop during
single-leg stance. Weakness results in a Trendelenburg gait pattern.
QUESTION 2
In normal gait, the hip reaches maximum flexion during which phase?
A. Loading response
B. Initial contact
C. Midstance
D. Mid-swing
CORRECT ANSWER: B. Initial contact
EXPERT RATIONALE: The hip is in maximum flexion at initial contact, approximately 30–
35 degrees.
QUESTION 3
An amputation that removes the midfoot and forefoot while saving the talus and
calcaneus is called a:
A. Modified Symes
B. Lisfranc
C. Chopart
D. Transmetatarsal
CORRECT ANSWER: C. Chopart
EXPERT RATIONALE: A Chopart amputation removes the midfoot and forefoot while
preserving the talus and calcaneus. Chopart is most likely to develop equinus
contracture due to unopposed pull of the gastrocnemius-soleus complex.
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QUESTION 4
Which of the following muscles are transected in a transmetatarsal amputation?
A. Peroneus longus
B. Extensor hallucis longus
C. Tibialis posterior
D. Tibialis anterior
CORRECT ANSWER: B. Extensor hallucis longus
EXPERT RATIONALE: The extensor hallucis longus is transected in a transmetatarsal
amputation.
QUESTION 5
Which of the following is the primary flexor of the elbow?
A. Biceps brachii
B. Brachioradialis
C. Anconeus
D. Brachialis
CORRECT ANSWER: D. Brachialis
EXPERT RATIONALE: The brachialis is the primary flexor of the elbow. The biceps brachii
also flexes the elbow but is a secondary flexor.
QUESTION 6
The most common congenital absence of a long bone in the extremities is:
A. Fibular hemimelia
B. Proximal Focal Femoral Deficiency
C. Congenital hypoplasia of the Tibia
D. Tibial phocomelia
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CORRECT ANSWER: A. Fibular hemimelia
EXPERT RATIONALE: Fibular hemimelia is the most common congenital absence of a
long bone in the extremities.
QUESTION 7
A patient presents with a foot slap at initial contact. This gait deviation is most likely due
to weakness of which muscle?
A. Gastrocnemius
B. Soleus
C. Tibialis anterior
D. Peroneus longus
CORRECT ANSWER: C. Tibialis anterior
EXPERT RATIONALE: Foot slap results from inadequate eccentric control of
plantarflexion after heel strike, indicating tibialis anterior weakness or poor prosthetic
foot selection.
QUESTION 8
The stance phase of gait constitutes approximately what percentage of the gait cycle at
normal walking speed?
A. 40%
B. 50%
C. 60%
D. 70%
CORRECT ANSWER: C. 60%
ABC Certified Prosthetist/Orthotist (CPO) Written
Exam | Latest Verified Questions and Detailed
Answers
OVERVIEW DESCRIPTION:
This Comprehensive set of multiple choice questions is designed for the ABC Certified
Prosthetist/Orthotist (CPO) Written Exam, a computer-based testing (CBT) assessment
administered by the American Board for Certification in Orthotics, Prosthetics & Pedorthics
(ABC). The exam uses multiple-choice questions with four answer choices each and may
capitalize or bold key terms in question stems to focus attention. It evaluates general
knowledge of patient management and foundational sciences across both orthotics and
prosthetics, with content distributed across foundational sciences; patient assessment and
evaluation, including history taking, physical exam, manual muscle testing, range of motion,
skin integrity, gait analysis, and cognitive/functional screening; formulation and
implementation of treatment plans, including prescription criteria, device recommendation
and design, componentry, material selection, and fabrication principles; follow-up and
clinical management, including device fit and alignment, patient complications, ongoing
maintenance, and outcome measurement; and professional practice, including safety
standards, healthcare documentation, insurance necessity, and ethical/professional
compliance.
QUESTION 1
A Trendelenburg gait occurs with weakness of which muscle?
A. Gluteus medius
B. Gluteus maximus
C. Adductor magnus
D. Rectus femoris
CORRECT ANSWER: A. Gluteus medius
,2|Page
EXPERT RATIONALE: The gluteus medius prevents contralateral pelvic drop during
single-leg stance. Weakness results in a Trendelenburg gait pattern.
QUESTION 2
In normal gait, the hip reaches maximum flexion during which phase?
A. Loading response
B. Initial contact
C. Midstance
D. Mid-swing
CORRECT ANSWER: B. Initial contact
EXPERT RATIONALE: The hip is in maximum flexion at initial contact, approximately 30–
35 degrees.
QUESTION 3
An amputation that removes the midfoot and forefoot while saving the talus and
calcaneus is called a:
A. Modified Symes
B. Lisfranc
C. Chopart
D. Transmetatarsal
CORRECT ANSWER: C. Chopart
EXPERT RATIONALE: A Chopart amputation removes the midfoot and forefoot while
preserving the talus and calcaneus. Chopart is most likely to develop equinus
contracture due to unopposed pull of the gastrocnemius-soleus complex.
,3|Page
QUESTION 4
Which of the following muscles are transected in a transmetatarsal amputation?
A. Peroneus longus
B. Extensor hallucis longus
C. Tibialis posterior
D. Tibialis anterior
CORRECT ANSWER: B. Extensor hallucis longus
EXPERT RATIONALE: The extensor hallucis longus is transected in a transmetatarsal
amputation.
QUESTION 5
Which of the following is the primary flexor of the elbow?
A. Biceps brachii
B. Brachioradialis
C. Anconeus
D. Brachialis
CORRECT ANSWER: D. Brachialis
EXPERT RATIONALE: The brachialis is the primary flexor of the elbow. The biceps brachii
also flexes the elbow but is a secondary flexor.
QUESTION 6
The most common congenital absence of a long bone in the extremities is:
A. Fibular hemimelia
B. Proximal Focal Femoral Deficiency
C. Congenital hypoplasia of the Tibia
D. Tibial phocomelia
, 4|Page
CORRECT ANSWER: A. Fibular hemimelia
EXPERT RATIONALE: Fibular hemimelia is the most common congenital absence of a
long bone in the extremities.
QUESTION 7
A patient presents with a foot slap at initial contact. This gait deviation is most likely due
to weakness of which muscle?
A. Gastrocnemius
B. Soleus
C. Tibialis anterior
D. Peroneus longus
CORRECT ANSWER: C. Tibialis anterior
EXPERT RATIONALE: Foot slap results from inadequate eccentric control of
plantarflexion after heel strike, indicating tibialis anterior weakness or poor prosthetic
foot selection.
QUESTION 8
The stance phase of gait constitutes approximately what percentage of the gait cycle at
normal walking speed?
A. 40%
B. 50%
C. 60%
D. 70%
CORRECT ANSWER: C. 60%
