CPT CPT Prosthetic Fitting & Alignment 1 — Questions and Answers
Question 1: What is the primary goal of static alignment in lower-limb prosthetics?
- Achieve a stable base of support in a standing position (Correct answer)
- Maximize walking speed on level surfaces
- Reduce prosthetic weight for the patient
- Improve cosmetic appearance of the prosthesis
Correct answer: Achieve a stable base of support in a standing position
Static alignment establishes a stable base of support while the patient stands, before dynamic adjustments are made during walking.
Question 2: During dynamic alignment, which professional typically observes the patient's gait and directs adjustments?
- The prosthetist (Correct answer)
- The physical therapist
- The orthotist
- The certified prosthetic technician
Correct answer: The prosthetist
The prosthetist observes the patient's gait during dynamic alignment and directs the prosthetic technician to make any necessary component adjustments.
Question 3: When aligning a transtibial (below-knee) prosthesis, the socket should be positioned so the pylon is oriented in which direction during stance phase?
- Vertically aligned with the ground reaction force (Correct answer)
- Slightly anterior to the residual limb
- Posterior to the midline of the foot
- Lateral to the socket centerline
Correct answer: Vertically aligned with the ground reaction force
Proper pylon alignment ensures the ground reaction force passes through the socket in a manner that mimics the natural biomechanical axis of the limb.
Question 4: Which tool is most commonly used by a prosthetic technician to verify the angular alignment of a prosthetic foot relative to the socket?
- Alignment jig or alignment device (Correct answer)
- Tape measure
- Caliper
- Torque wrench
Correct answer: Alignment jig or alignment device
An alignment jig or dedicated alignment device allows the technician to accurately set and verify the angular relationship between the socket and prosthetic foot.
Question 5: What does excessive toe-out (external foot rotation) in a transtibial prosthesis most likely indicate?
- Excessive external rotation of the pylon (Correct answer)
- Insufficient socket flexion
- Prosthetic foot set too far posterior
- Socket trim line placed too proximally
Correct answer: Excessive external rotation of the pylon
Excessive toe-out is typically caused by too much external rotation in the pylon or foot attachment, which must be corrected during bench or dynamic alignment.
Question 6: During bench alignment of a transfemoral (above-knee) prosthesis, the knee unit is generally set in how many degrees of flexion?
- 0 to 5 degrees of flexion (Correct answer)
- 10 to 15 degrees of flexion
- 20 to 25 degrees of flexion
- 30 to 40 degrees of flexion
Correct answer: 0 to 5 degrees of flexion
Bench alignment typically starts with the knee unit in 0–5 degrees of flexion to provide initial stability before dynamic refinements are made.
CPT CPT Prosthetic Fitting & Alignment 1
What is the primary goal of static alignment in lower-limb prosthetics?