PROSTHETIC CPM LATEST 2026 EXAM QUESTIONS AND
ANSWERS GRADED A+
✔✔TF Ischial Containment Socket Principles - ✔✔Femur held in adduction
Very intimate fit
Triangular shape
ML compression
Indicated for: shorter limbs, requires less voluntary control
Potential for ischial weightbearing, high proximal trimline
Gluteal and hydrostatic weightbearing
Triangular shape
✔✔TF MAS (ramal containment) Socket Principles - ✔✔Hydrostaic weightbearing
Lower trimlines
Ramal buttress for ML control
✔✔TF Subischial Socket Principles - ✔✔Much lower trimlines - KD
Use with anatomical suspension or vacuum
Long limbs, requires good control and normal ROM of hip
✔✔TF Quad Socket Principles - ✔✔4 well-defined walls
Rectangular shape
Ischial/gluteal weightbearing
AP control - Lack of ML support
Contours for flexors/extensors
Indicated for longer limbs, good voluntary control, previous user
✔✔Subischial triangle - ✔✔Inferior ramus, gracilis, semitendinosis
✔✔Scarpa's triangle - ✔✔Inguinal ligament, sartorius, adductor longus
✔✔Ischial containment trimlines - ✔✔Anterior 50mm (2") proximal to IT
Posterior 25mm (1") proximal to IT
Medial at ischial level in line of progression
Lateral 90 mm (3") proximal to IT
✔✔Quad trimlines - ✔✔Anterior: 2.5" proximal to IT
Medial: at ischial level
Lateral: 2.5" proximal to IT
Posterior: at ischial level
✔✔KD Suspension - ✔✔Anatomical with foam liner - Pros: rotational control, increased
suspension in swing phase; Cons: suspension localized to one area, not able to use
with fluctuating edema
Cushion liner
, Window/door
Boa
Lacer
Seal-in suction
✔✔Liner + Pin (TF) - ✔✔Pros: Seated donning, positive lock
Cons: difficult due to pin angle, soft tissue movement, pistoning/milking of tissue
✔✔Liner + Lanyard (TF) - ✔✔Pros: Seated donning, Great for low mobility/balance,
positive lock
Cons: pistoning/milking of tissue, single point connection, must have good hand
strength
✔✔Skin fit suction (TF) - ✔✔Pull sock + expulsion valve
Pros: Improved proprioception, Perceived as lighter, Eliminates pistoning
Cons: Can be hard on skin, can't have volume fluctuation, must stand to don, need
precise fit
✔✔Seal-in liner (TF) - ✔✔Pros: Improved proprioception, perceived as lighter,
eliminates pistoning, shear forces moderated by liner
Cons: must have good hygiene, must have good hand strength, must stand to don,
need precise fit
✔✔Elevated vacuum (TF) - ✔✔mechanical or electronic
Pros: Improved proprioception, Can be used with subischial trimlines
Cons: requires cognitive ability, pump adds weight
✔✔Hip joint + Pelvic band (TF) - ✔✔Sock interface
Pros: Maximal ML control, Good if weak abductors or short residual limb, some
rotational control
Cons: heavy, bulky, pistoning, hard to don, uncomfortable when sitting
Pelvic band b/w iliac crests and trochanters
Joint 12mm anterior and 25mm proximal to GT
✔✔Silesian belt/TES belt - ✔✔Pros:Auxiliary, controls rotation, allows for volume
changes
Cons: not good for independent suspension, allows pistoning
Attached 6mm posterior and 6mm proximal to GT
Pulls into adduction
✔✔TT PTB Socket Design - ✔✔Indicated for short or bony limbs
Rotational control
Depressions: MPT bar, medial flare, medial shaft, pretibial area, politeal area, lateral
fibula shaft, interosseus space
Buildups: tibial crest, lateral flare, fib head, distal fibula, distal anterior tibia
ANSWERS GRADED A+
✔✔TF Ischial Containment Socket Principles - ✔✔Femur held in adduction
Very intimate fit
Triangular shape
ML compression
Indicated for: shorter limbs, requires less voluntary control
Potential for ischial weightbearing, high proximal trimline
Gluteal and hydrostatic weightbearing
Triangular shape
✔✔TF MAS (ramal containment) Socket Principles - ✔✔Hydrostaic weightbearing
Lower trimlines
Ramal buttress for ML control
✔✔TF Subischial Socket Principles - ✔✔Much lower trimlines - KD
Use with anatomical suspension or vacuum
Long limbs, requires good control and normal ROM of hip
✔✔TF Quad Socket Principles - ✔✔4 well-defined walls
Rectangular shape
Ischial/gluteal weightbearing
AP control - Lack of ML support
Contours for flexors/extensors
Indicated for longer limbs, good voluntary control, previous user
✔✔Subischial triangle - ✔✔Inferior ramus, gracilis, semitendinosis
✔✔Scarpa's triangle - ✔✔Inguinal ligament, sartorius, adductor longus
✔✔Ischial containment trimlines - ✔✔Anterior 50mm (2") proximal to IT
Posterior 25mm (1") proximal to IT
Medial at ischial level in line of progression
Lateral 90 mm (3") proximal to IT
✔✔Quad trimlines - ✔✔Anterior: 2.5" proximal to IT
Medial: at ischial level
Lateral: 2.5" proximal to IT
Posterior: at ischial level
✔✔KD Suspension - ✔✔Anatomical with foam liner - Pros: rotational control, increased
suspension in swing phase; Cons: suspension localized to one area, not able to use
with fluctuating edema
Cushion liner
, Window/door
Boa
Lacer
Seal-in suction
✔✔Liner + Pin (TF) - ✔✔Pros: Seated donning, positive lock
Cons: difficult due to pin angle, soft tissue movement, pistoning/milking of tissue
✔✔Liner + Lanyard (TF) - ✔✔Pros: Seated donning, Great for low mobility/balance,
positive lock
Cons: pistoning/milking of tissue, single point connection, must have good hand
strength
✔✔Skin fit suction (TF) - ✔✔Pull sock + expulsion valve
Pros: Improved proprioception, Perceived as lighter, Eliminates pistoning
Cons: Can be hard on skin, can't have volume fluctuation, must stand to don, need
precise fit
✔✔Seal-in liner (TF) - ✔✔Pros: Improved proprioception, perceived as lighter,
eliminates pistoning, shear forces moderated by liner
Cons: must have good hygiene, must have good hand strength, must stand to don,
need precise fit
✔✔Elevated vacuum (TF) - ✔✔mechanical or electronic
Pros: Improved proprioception, Can be used with subischial trimlines
Cons: requires cognitive ability, pump adds weight
✔✔Hip joint + Pelvic band (TF) - ✔✔Sock interface
Pros: Maximal ML control, Good if weak abductors or short residual limb, some
rotational control
Cons: heavy, bulky, pistoning, hard to don, uncomfortable when sitting
Pelvic band b/w iliac crests and trochanters
Joint 12mm anterior and 25mm proximal to GT
✔✔Silesian belt/TES belt - ✔✔Pros:Auxiliary, controls rotation, allows for volume
changes
Cons: not good for independent suspension, allows pistoning
Attached 6mm posterior and 6mm proximal to GT
Pulls into adduction
✔✔TT PTB Socket Design - ✔✔Indicated for short or bony limbs
Rotational control
Depressions: MPT bar, medial flare, medial shaft, pretibial area, politeal area, lateral
fibula shaft, interosseus space
Buildups: tibial crest, lateral flare, fib head, distal fibula, distal anterior tibia
