DPT Prosthetics & Orthotics 2 — Questions and Answers
Question 1: A transtibial amputee demonstrates excessive heel rise during early swing phase. The most likely cause is:
- Prosthetic foot set too far anterior
- Insufficient plantarflexion resistance in the heel (Correct answer)
- Excessive dorsiflexion range in the prosthetic foot
- Socket fit too loose proximally
Correct answer: Insufficient plantarflexion resistance in the heel
A heel that is too soft (insufficient plantarflexion resistance) allows rapid uncontrolled dorsiflexion, causing the heel to rise excessively during early swing.
Question 2: The most common cause of skin breakdown in prosthetic users is:
- Allergic reaction to socket materials
- Shear forces from pistoning or poor socket fit (Correct answer)
- Excessive prosthetic weight loading
- Prolonged use of suspension sleeves
Correct answer: Shear forces from pistoning or poor socket fit
Pistoning (vertical movement of the residual limb within the socket) and poor socket fit generate shear forces and friction that are the primary causes of skin breakdown.
Question 3: Which type of upper extremity orthosis is most appropriate for a patient with radial nerve palsy presenting with wrist drop?
- Resting hand splint in intrinsic-plus position
- Cock-up wrist splint in static neutral position
- Dynamic wrist extension splint (Correct answer)
- Ulnar gutter splint
Correct answer: Dynamic wrist extension splint
A dynamic wrist extension splint provides passive wrist extension to compensate for wrist drop while allowing active finger movement, addressing the key functional deficit of radial nerve palsy.
Question 4: Residual limb shaping following amputation surgery is best achieved by:
- Surgical revision to create a conical shape
- Figure-8 compression wrapping or use of shrinker socks (Correct answer)
- Strengthening exercises for residual limb musculature
- Desensitization massage therapy alone
Correct answer: Figure-8 compression wrapping or use of shrinker socks
Figure-8 compression wrapping or shrinker socks apply graduated pressure that reduces edema and shapes the residual limb into a conical form suitable for prosthetic socket fitting.
Question 5: A Syme amputation is best described as:
- Amputation through the midfoot at Lisfranc's joint
- Ankle disarticulation with preservation of the heel fat pad (Correct answer)
- Amputation through the tibia 5 cm distal to the knee
- Partial calcanectomy with preservation of metatarsals
Correct answer: Ankle disarticulation with preservation of the heel fat pad
A Syme amputation involves disarticulation at the ankle joint with preservation of the heel fat pad, which provides a durable end-bearing surface.
Question 6: A patient with a transfemoral prosthesis demonstrates excessive lateral trunk lean toward the prosthetic side during stance. The most likely cause is:
- Prosthetic foot too soft with excessive pronation
- Prosthesis too short or inadequate mediolateral socket alignment (Correct answer)
- Prosthetic knee unit with too much resistance
- Excessive hip flexion contracture on the prosthetic side
Correct answer: Prosthesis too short or inadequate mediolateral socket alignment
Lateral trunk lean over the prosthetic side is most commonly caused by a prosthesis that is too short or improper mediolateral alignment, prompting the patient to shift weight to compensate.
Question 7: The primary principle behind total contact casting (TCC) for healing diabetic plantar ulcers is:
- Immobilizing the ankle to prevent all dorsiflexion motion
- Redistributing plantar pressure away from the wound across the entire foot and lower leg (Correct answer)
- Providing a waterproof antimicrobial wound environment
- Correcting equinovarus deformity that caused the ulcer
Correct answer: Redistributing plantar pressure away from the wound across the entire foot and lower leg
TCC redistributes plantar pressure broadly over the entire contact surface of the foot and lower leg, offloading the wound area to allow healing.
DPT Prosthetics & Orthotics 2
A transtibial amputee demonstrates excessive heel rise during early swing phase.
The most likely cause is: