CPT Maintenance, Repairs, & Quality Assurance 2

Question 1

When inspecting a transtibial prosthetic socket for wear, which area is MOST prone to stress cracking in a laminated socket?

Accepted Answer

The proximal brim trim line

Answer

The proximal brim trim line experiences the greatest cyclical stress during donning and doffing, making it the most common site for stress cracks in laminated sockets.

Question 2

A patient reports that their endoskeletal prosthetic knee makes a clicking noise only during swing phase. The MOST likely cause is:

Accepted Answer

Worn extension bumper or stop

Answer

A clicking sound specifically during swing phase is characteristic of a worn or deteriorated extension bumper or stop reaching end range of motion.

Question 3

Which solvent is most appropriate for cleaning residual adhesive from a carbon fiber socket before re-lamination?

Accepted Answer

Isopropyl alcohol

Answer

Isopropyl alcohol effectively removes adhesive residue without degrading carbon fiber or epoxy matrix materials used in prosthetic sockets.

Question 4

During a quality check of a new SACH foot, the technician notices the keel extends too far distally. This error will MOST likely cause:

Accepted Answer

Increased toe stiffness limiting late stance energy return

Answer

A keel extending too far distally increases toe lever arm stiffness, restricting terminal stance rollover and reducing energy return.

Question 5

A transfemoral prosthesis with a suction suspension system is leaking air at the valve housing. After replacing the valve, the appropriate QA check is to:

Accepted Answer

Apply soapy water around the valve and listen for hissing

Answer

Applying soapy water around the valve housing and watching for bubble formation is the standard bench test to verify an airtight seal after valve replacement.

(CPT) Certified Prosthetic Technician Practice Test

(CPT) Certified Prosthetic Technician Practice Test

CPT Maintenance, Repairs, & Quality Assurance 2