DPT Prosthetics & Orthotics 1 — Questions and Answers
Question 1: What is the primary purpose of total contact in a transtibial prosthetic socket?
- To increase walking speed
- To distribute pressure evenly across the residual limb (Correct answer)
- To prevent knee hyperextension
- To accommodate volumetric fluctuations
Correct answer: To distribute pressure evenly across the residual limb
Total contact distributes pressure evenly across the entire residual limb surface, preventing focal high-pressure areas that cause skin breakdown.
Question 2: Which type of ankle-foot orthosis (AFO) is most appropriate for a patient with isolated foot drop due to peroneal nerve palsy?
- Solid AFO with plantarflexion stop
- Articulated AFO with dorsiflexion assist
- Posterior leaf spring AFO (Correct answer)
- Ground reaction AFO (GRAFO)
Correct answer: Posterior leaf spring AFO
A posterior leaf spring AFO provides dorsiflexion assist during swing phase while allowing some sagittal motion, making it ideal for isolated foot drop with preserved push-off.
Question 3: The K-level classification system used in lower limb prosthetic prescription is primarily based on:
- The patient's age and body weight
- The patient's rehabilitation potential and functional mobility level (Correct answer)
- The type and level of amputation
- The patient's pain level and comorbidities
Correct answer: The patient's rehabilitation potential and functional mobility level
The K-level system (K0–K4) classifies patients by their rehabilitation potential and expected functional mobility to guide appropriate prosthetic component selection.
Question 4: Why is initial flexion (5–10°) commonly built into a transfemoral prosthetic socket?
- To prevent hip adduction during swing phase
- To facilitate hip extensor activation and prevent excessive lumbar lordosis (Correct answer)
- To increase stride length on the prosthetic side
- To reduce energy expenditure at high walking speeds
Correct answer: To facilitate hip extensor activation and prevent excessive lumbar lordosis
Initial flexion positions the residual limb so the hip extensors can fire effectively during stance and prevents compensatory lumbar lordosis.
Question 5: Which prosthetic foot design is classified as an energy-storing and return (ESAR) foot?
- SACH (Solid Ankle Cushion Heel) foot
- Single-axis foot
- Carbon fiber dynamic response foot (Correct answer)
- Multi-axial foot
Correct answer: Carbon fiber dynamic response foot
Carbon fiber dynamic response feet deflect and store energy during loading, then return that energy at push-off, mimicking the function of the Achilles tendon and plantar fascia.
Question 6: What is the primary biomechanical indication for prescribing a floor-reaction AFO (GRAFO)?
- Foot drop with preserved ankle dorsiflexor strength
- Crouch gait due to weak knee extensors or plantarflexors (Correct answer)
- Spastic equinovarus with fixed deformity
- Mediolateral ankle instability following inversion sprain
Correct answer: Crouch gait due to weak knee extensors or plantarflexors
A GRAFO blocks ankle dorsiflexion, redirecting the ground reaction force anterior to the knee to create a knee extension moment that corrects crouch gait.
Question 7: Which outcome measure was specifically designed and validated to assess functional mobility and predict prosthetic component needs in amputees?
- Tinetti Performance-Oriented Mobility Assessment
- Amputee Mobility Predictor (AMP) (Correct answer)
- Berg Balance Scale
- Functional Independence Measure (FIM)
Correct answer: Amputee Mobility Predictor (AMP)
The Amputee Mobility Predictor (AMP) was developed specifically for the amputee population and is used to assess functional mobility and guide prosthetic prescription.
DPT Prosthetics & Orthotics 1
What is the primary purpose of total contact in a transtibial prosthetic socket?