CPT Prosthetic Components & Technology 2

Question 1

Microprocessor-controlled prosthetic knees (MPKs) use onboard sensors primarily to assess which variables in real time?

Accepted Answer

Angular velocity, acceleration, and load data to modulate hydraulic resistance

Answer

Socket pressure and residual limb temperature only

Answer

Battery voltage and Bluetooth signal strength

Answer

Patient heart rate and oxygen saturation

Question 2

What type of wrist unit allows a transradial prosthesis user to pre-position the terminal device in multiple planes of rotation?

Accepted Answer

Flexion-rotation wrist unit (flexion/extension and rotation)

Answer

Rigid wrist unit

Answer

Flexion wrist unit with a single hinge

Answer

Locking wrist unit only with extension

Question 3

Which suspension method for a transtibial prosthesis relies on a urethane or silicone liner rolled onto the residual limb, with a locking pin that engages a clutch mechanism in the socket?

Accepted Answer

Pin/lock (lanyard) suspension

Answer

Supracondylar cuff suspension

Answer

Suction suspension with one-way valve

Answer

Elevated vacuum suspension (EVS)

Question 4

Elevated vacuum suspension (EVS) systems improve prosthetic suspension and residual limb health primarily by:

Accepted Answer

Maintaining negative pressure within the socket to reduce volume fluctuation and pistoning

Answer

Adding mechanical locking pins at the distal end

Answer

Using supracondylar brim extensions to grip the femoral condyles

Answer

Applying a neoprene sleeve over the proximal socket brim

Question 5

A myoelectric prosthetic hand uses surface electromyography (sEMG) signals from residual limb muscles to control the hand. Which muscle pair is most commonly used for transradial myoelectric control?

Accepted Answer

Wrist flexors and wrist extensors

Answer

Biceps brachii and triceps brachii

Answer

Pectoralis major and serratus anterior

Answer

Deltoid anterior and deltoid posterior

Question 6

In lower-limb prosthetics, a dynamic response (energy-return) prosthetic foot's carbon fiber keel primarily stores energy during which phase of gait?

Accepted Answer

Initial contact and loading response (heel strike)

Answer

Mid-swing phase

Answer

Terminal swing phase

Answer

Pre-swing toe-off only

Question 7

Which feature distinguishes a multi-axial prosthetic foot from a single-axis foot?

Accepted Answer

It provides motion in the frontal plane (inversion/eversion) in addition to sagittal plane movement

Answer

It is made entirely of carbon fiber with no moving parts

Answer

It has a higher energy return coefficient than dynamic response feet

Answer

It eliminates the need for a torsion adapter