ABC ORTHOTICS & PROSTHETICS BOARD WRITTEN EXAM TEST
BANK ACTUAL EXAM QUESTIONS AND CORRECT DETAILED
ANSWERS A NEW UPDATED VERSION LATEST 2026-2027 (100%
CORRECT VERIFIED ANSWERS/ABC ORTHOTICS &
PROSTHETICS BOARD WRITTEN EXAM EDITION 2026
GUARANTEED PASS A+|INSTANT DOWNLOAD PDF
During normal gait, which muscle group primarily contracts eccentrically
immediately after initial contact to control the rate of knee flexion?
A. Hamstrings
B. Quadriceps
C. Gastrocnemius
D. Tibialis anterior
ANSWER: B. Quadriceps
Rationale: The quadriceps contract eccentrically during early stance to control
knee flexion after loading response. This allows controlled shock absorption and
prevents excessive knee collapse. The hamstrings contribute to knee control but are
not the primary muscle group responsible for this function immediately after
,loading. The gastrocnemius becomes particularly important later in stance, while
tibialis anterior controls plantarflexion of the foot after initial contact.
A patient demonstrates excessive knee flexion during early stance while using a
transtibial prosthesis. Which prosthetic alignment change is most likely to reduce
this tendency?
A. Move the socket anterior relative to the foot
B. Move the socket posterior relative to the foot
C. Increase plantarflexion of the foot
D. Decrease heel resistance
ANSWER: A. Move the socket anterior relative to the foot
Rationale: Moving the socket anterior relative to the foot tends to shift the ground-
reaction-force relationship and can reduce the external knee-flexion moment
during early stance. Excessive knee flexion may also have several causes,
including excessive plantarflexion, insufficient heel resistance, or patient
weakness, so alignment should be evaluated systematically rather than changed
blindly. The key is to identify the mechanical relationship between the ground
reaction force and the knee.
A patient with a transfemoral prosthesis exhibits excessive lateral trunk lean
toward the prosthetic side during stance. Which problem should be considered
first?
A. Excessive prosthetic toe-out
B. Abductor weakness or insufficient prosthetic support
,C. Excessive knee stability
D. Excessive socket flexion
ANSWER: B. Abductor weakness or insufficient prosthetic support
Rationale: Lateral trunk lean toward the prosthetic side can decrease the external
hip-abduction moment and reduce the demand on weak hip abductors. It may also
occur because of inadequate socket support or discomfort. Excessive toe-out does
not typically produce this classic compensation, while excessive knee stability and
socket flexion are not the primary explanations.
Which plane primarily describes varus and valgus alignment?
A. Sagittal
B. Transverse
C. Frontal
D. Oblique
ANSWER: C. Frontal
Rationale: Varus and valgus describe angular relationships in the frontal plane.
Flexion and extension are primarily sagittal-plane motions, while internal and
external rotation occur in the transverse plane. Recognizing the plane of motion is
essential when interpreting alignment and gait deviations.
, A patient has a fixed knee flexion contracture before receiving a transfemoral
prosthesis. Which socket modification is generally appropriate to accommodate the
contracture?
A. Decrease socket flexion
B. Increase socket flexion to approximate the contracture angle
C. Fully extend the socket regardless of the contracture
D. Increase socket adduction only
ANSWER: B. Increase socket flexion to approximate the contracture angle
Rationale: A transfemoral socket is generally flexed to accommodate a knee flexion
contracture and to place the residual limb in a functional position. Attempting to
force the residual limb into full extension can increase pressure, discomfort, and
gait difficulty. Socket adduction is related to frontal-plane positioning rather than
directly accommodating a fixed sagittal-plane contracture.
Which finding most strongly indicates a potentially serious skin problem requiring
prompt evaluation in a prosthetic user?
A. Mild transient redness that disappears within several minutes
B. Persistent erythema with blister formation
C. Mild sweating after exercise
D. Temporary indentation immediately after removing the liner
ANSWER: B. Persistent erythema with blister formation
BANK ACTUAL EXAM QUESTIONS AND CORRECT DETAILED
ANSWERS A NEW UPDATED VERSION LATEST 2026-2027 (100%
CORRECT VERIFIED ANSWERS/ABC ORTHOTICS &
PROSTHETICS BOARD WRITTEN EXAM EDITION 2026
GUARANTEED PASS A+|INSTANT DOWNLOAD PDF
During normal gait, which muscle group primarily contracts eccentrically
immediately after initial contact to control the rate of knee flexion?
A. Hamstrings
B. Quadriceps
C. Gastrocnemius
D. Tibialis anterior
ANSWER: B. Quadriceps
Rationale: The quadriceps contract eccentrically during early stance to control
knee flexion after loading response. This allows controlled shock absorption and
prevents excessive knee collapse. The hamstrings contribute to knee control but are
not the primary muscle group responsible for this function immediately after
,loading. The gastrocnemius becomes particularly important later in stance, while
tibialis anterior controls plantarflexion of the foot after initial contact.
A patient demonstrates excessive knee flexion during early stance while using a
transtibial prosthesis. Which prosthetic alignment change is most likely to reduce
this tendency?
A. Move the socket anterior relative to the foot
B. Move the socket posterior relative to the foot
C. Increase plantarflexion of the foot
D. Decrease heel resistance
ANSWER: A. Move the socket anterior relative to the foot
Rationale: Moving the socket anterior relative to the foot tends to shift the ground-
reaction-force relationship and can reduce the external knee-flexion moment
during early stance. Excessive knee flexion may also have several causes,
including excessive plantarflexion, insufficient heel resistance, or patient
weakness, so alignment should be evaluated systematically rather than changed
blindly. The key is to identify the mechanical relationship between the ground
reaction force and the knee.
A patient with a transfemoral prosthesis exhibits excessive lateral trunk lean
toward the prosthetic side during stance. Which problem should be considered
first?
A. Excessive prosthetic toe-out
B. Abductor weakness or insufficient prosthetic support
,C. Excessive knee stability
D. Excessive socket flexion
ANSWER: B. Abductor weakness or insufficient prosthetic support
Rationale: Lateral trunk lean toward the prosthetic side can decrease the external
hip-abduction moment and reduce the demand on weak hip abductors. It may also
occur because of inadequate socket support or discomfort. Excessive toe-out does
not typically produce this classic compensation, while excessive knee stability and
socket flexion are not the primary explanations.
Which plane primarily describes varus and valgus alignment?
A. Sagittal
B. Transverse
C. Frontal
D. Oblique
ANSWER: C. Frontal
Rationale: Varus and valgus describe angular relationships in the frontal plane.
Flexion and extension are primarily sagittal-plane motions, while internal and
external rotation occur in the transverse plane. Recognizing the plane of motion is
essential when interpreting alignment and gait deviations.
, A patient has a fixed knee flexion contracture before receiving a transfemoral
prosthesis. Which socket modification is generally appropriate to accommodate the
contracture?
A. Decrease socket flexion
B. Increase socket flexion to approximate the contracture angle
C. Fully extend the socket regardless of the contracture
D. Increase socket adduction only
ANSWER: B. Increase socket flexion to approximate the contracture angle
Rationale: A transfemoral socket is generally flexed to accommodate a knee flexion
contracture and to place the residual limb in a functional position. Attempting to
force the residual limb into full extension can increase pressure, discomfort, and
gait difficulty. Socket adduction is related to frontal-plane positioning rather than
directly accommodating a fixed sagittal-plane contracture.
Which finding most strongly indicates a potentially serious skin problem requiring
prompt evaluation in a prosthetic user?
A. Mild transient redness that disappears within several minutes
B. Persistent erythema with blister formation
C. Mild sweating after exercise
D. Temporary indentation immediately after removing the liner
ANSWER: B. Persistent erythema with blister formation
