PROSTHETIC CPM COMPLETE QUESTIONS
AND ANSWERS STUDY GUIDE FULLY
VERIFIED
⩥ What are the advantages and disadvantages to a weight activated
stance control knee.
Answer: Adv: stable, good for new amputees to learn gait,
Dis, delayed swing phase, must fully unload knee
⩥ What are the advantages and disadvantages to a polycentric knee.
Answer: Adv: knee is inherently more stable as KC is superior and
posterior, shortens during swing better for cosmesis and long residuum
Dis: increased weight, cost, maintenance
⩥ What are the advantages and disadvantages to a manual lock knee.
Answer: Adv: most stable in stance, eliminates potential for buckling
Dis: long swing limb, energy inefficient, abnormal swing, difficult to sit
down in.
⩥ What are the advantages and disadvantages to a pneumatic/hydraulic
knee.
Answer: Adv: Able to vary cadence, provides swing and stance phase
control, more natural gait
,Dis: increased cost, maintenance, must be high enough K level
⩥ If a TF patient is exhibiting a medial whip during swing phase what is
the likely cause.
Answer: Knee is too externally rotated, need to internally rotate
(Rotate towards the whip)
⩥ If a TF patient is exhibiting a lateral whip during swing phase what is
the likely cause.
Answer: Knee to internally rotated, need to externally rotated the knee
⩥ What is TF bench alignment.
Answer: SOCKET= Contracture+ 5 degrees of flexion, Adduction 6-7
degrees (match sound side)
KNEE= 3-5 external rotation, weight line 5-15mm anterior to KC
FOOT= 30-50 mm outset from ischium, 5-7 degrees of toe out
⩥ How should you set the socket adduction and flexion angle for a TF
patient with a 10 degree hip flexion contracture..
Answer: Posterior and Medial trim line should be parallel to the floor
(adduction)
15 degrees of socket flexion
,⩥ What is the bench alignment for a Transtibial prosthesis.
Answer: SOCKET: Flexed 5 degrees, 37 mm anterior to the foot bolt
Foot: 12 mm inset relative to bisection of socket, 5-7 degrees of toe out(
2nd ray)
⩥ Identify the cause of the pressure/pain and how you would fix the
problem for blistering/discoloration on the distal limb. Socket fit is
correct.
Answer: Pistoning/milking of prosthesis during swing phase, patient
donning liner incorrectly
⩥ Identify the cause of the pressure/pain and how you would fix the
problem for upper extremity terminal device opening with elbow
flexion.
Answer: Too much force with in the system, add rubber bands, check
housing clearance, move forearm lift tab distally, Move proximal base
plate retainer(PBPR) anterior lateral or proximal
⩥ Identify the cause of the pressure/pain and how you would fix the
problem for upper extremity device that will not open all the way.
Answer: Too much excursion in the system for TH,
Tighten CAS, Check housing clearance and not to long, Move EFA
proximal, Move PBPR posterior, distal, medial, decrease rubber bands
, ⩥ Identify the cause of the pressure/pain and how you would fix the
problem for transfemoral pain and redness on the lateral distal femur.
Answer: Socket is too Adducted, not enough control on shaft of femur
Pad shaft of femur, abduct socket, decrease Varus moment
⩥ Identify the cause of the pressure/pain and how you would fix the
problem for symes pain on the medial/lateral malleolus.
Answer: Is the alignment correct, foot to inset or outset
⩥ Identify the cause of the pressure/pain and how you would fix the
problem for transtibial pain/redness on the bottom, distal patella, and
fibular head.
Answer: Loss of volume, increase sock ply
⩥ Identify the cause of the pressure/pain and how you would fix the
problem for knee disarticulation using too many socks.
Answer: Pad the socket, socket replacement loss of volume
⩥ Identify the cause of the pressure/pain and how you would fix the
problem for anterior distal pressure.
Answer: Socket cause= insufficient relief, AP to large, loss of volume
Alignment cause= socket is too flexed
AND ANSWERS STUDY GUIDE FULLY
VERIFIED
⩥ What are the advantages and disadvantages to a weight activated
stance control knee.
Answer: Adv: stable, good for new amputees to learn gait,
Dis, delayed swing phase, must fully unload knee
⩥ What are the advantages and disadvantages to a polycentric knee.
Answer: Adv: knee is inherently more stable as KC is superior and
posterior, shortens during swing better for cosmesis and long residuum
Dis: increased weight, cost, maintenance
⩥ What are the advantages and disadvantages to a manual lock knee.
Answer: Adv: most stable in stance, eliminates potential for buckling
Dis: long swing limb, energy inefficient, abnormal swing, difficult to sit
down in.
⩥ What are the advantages and disadvantages to a pneumatic/hydraulic
knee.
Answer: Adv: Able to vary cadence, provides swing and stance phase
control, more natural gait
,Dis: increased cost, maintenance, must be high enough K level
⩥ If a TF patient is exhibiting a medial whip during swing phase what is
the likely cause.
Answer: Knee is too externally rotated, need to internally rotate
(Rotate towards the whip)
⩥ If a TF patient is exhibiting a lateral whip during swing phase what is
the likely cause.
Answer: Knee to internally rotated, need to externally rotated the knee
⩥ What is TF bench alignment.
Answer: SOCKET= Contracture+ 5 degrees of flexion, Adduction 6-7
degrees (match sound side)
KNEE= 3-5 external rotation, weight line 5-15mm anterior to KC
FOOT= 30-50 mm outset from ischium, 5-7 degrees of toe out
⩥ How should you set the socket adduction and flexion angle for a TF
patient with a 10 degree hip flexion contracture..
Answer: Posterior and Medial trim line should be parallel to the floor
(adduction)
15 degrees of socket flexion
,⩥ What is the bench alignment for a Transtibial prosthesis.
Answer: SOCKET: Flexed 5 degrees, 37 mm anterior to the foot bolt
Foot: 12 mm inset relative to bisection of socket, 5-7 degrees of toe out(
2nd ray)
⩥ Identify the cause of the pressure/pain and how you would fix the
problem for blistering/discoloration on the distal limb. Socket fit is
correct.
Answer: Pistoning/milking of prosthesis during swing phase, patient
donning liner incorrectly
⩥ Identify the cause of the pressure/pain and how you would fix the
problem for upper extremity terminal device opening with elbow
flexion.
Answer: Too much force with in the system, add rubber bands, check
housing clearance, move forearm lift tab distally, Move proximal base
plate retainer(PBPR) anterior lateral or proximal
⩥ Identify the cause of the pressure/pain and how you would fix the
problem for upper extremity device that will not open all the way.
Answer: Too much excursion in the system for TH,
Tighten CAS, Check housing clearance and not to long, Move EFA
proximal, Move PBPR posterior, distal, medial, decrease rubber bands
, ⩥ Identify the cause of the pressure/pain and how you would fix the
problem for transfemoral pain and redness on the lateral distal femur.
Answer: Socket is too Adducted, not enough control on shaft of femur
Pad shaft of femur, abduct socket, decrease Varus moment
⩥ Identify the cause of the pressure/pain and how you would fix the
problem for symes pain on the medial/lateral malleolus.
Answer: Is the alignment correct, foot to inset or outset
⩥ Identify the cause of the pressure/pain and how you would fix the
problem for transtibial pain/redness on the bottom, distal patella, and
fibular head.
Answer: Loss of volume, increase sock ply
⩥ Identify the cause of the pressure/pain and how you would fix the
problem for knee disarticulation using too many socks.
Answer: Pad the socket, socket replacement loss of volume
⩥ Identify the cause of the pressure/pain and how you would fix the
problem for anterior distal pressure.
Answer: Socket cause= insufficient relief, AP to large, loss of volume
Alignment cause= socket is too flexed
