CPT Anatomy, Biomechanics, & Gait Analysis 2 — Questions and Answers
Question 1: Which muscle group is primarily responsible for eccentric control of the knee during the loading response phase of gait?
- Quadriceps (Correct answer)
- Hamstrings
- Gastrocnemius
- Tibialis anterior
Correct answer: Quadriceps
The quadriceps contract eccentrically during loading response to control knee flexion and absorb shock.
Question 2: In a transtibial amputee, which gait deviation is most commonly caused by excessive socket flexion?
- Lateral trunk bending
- Anterior trunk lean (Correct answer)
- Circumduction
- Vaulting
Correct answer: Anterior trunk lean
Excessive socket flexion shifts the patient's center of mass forward, causing an anterior trunk lean during stance.
Question 3: The tensor fasciae latae muscle primarily functions as which of the following during gait?
- Hip extensor and external rotator
- Hip flexor, abductor, and internal rotator (Correct answer)
- Knee flexor and plantar flexor
- Lumbar stabilizer and hip adductor
Correct answer: Hip flexor, abductor, and internal rotator
The tensor fasciae latae performs hip flexion, abduction, and internal rotation, contributing to swing phase initiation.
Question 4: During normal gait, at what percentage of the gait cycle does toe-off typically occur?
- 40%
- 50%
- 62% (Correct answer)
- 75%
Correct answer: 62%
Toe-off occurs at approximately 62% of the gait cycle, marking the end of stance and beginning of swing phase.
Question 5: Which anatomical structure forms the primary medial stabilizer of the ankle joint?
- Calcaneofibular ligament
- Anterior talofibular ligament
- Deltoid ligament (Correct answer)
- Spring ligament
Correct answer: Deltoid ligament
The deltoid (medial collateral) ligament is a strong, triangular structure providing primary medial ankle stability.
Question 6: A transfemoral amputee who walks with a lateral trunk lean toward the prosthetic side most likely has:
- Excessive prosthetic knee friction
- Inadequate prosthetic side hip abductor strength or a short prosthesis (Correct answer)
- Excessive socket adduction
- A knee flexion contracture
Correct answer: Inadequate prosthetic side hip abductor strength or a short prosthesis
Lateral lean toward the prosthetic side (Trendelenburg gait) results from weak residual limb hip abductors or a prosthesis that is too short.
Question 7: Which term describes the rotational force that causes the prosthetic foot to pronate or supinate relative to the socket during gait?
- Shear stress
- Torsional moment (Correct answer)
- Bending moment
- Compressive load
Correct answer: Torsional moment
A torsional moment is the rotational force acting along the longitudinal axis of the prosthetic limb that influences foot alignment.
CPT Anatomy, Biomechanics, & Gait Analysis 2
Which muscle group is primarily responsible for eccentric control of the knee during the loading response phase of gait?