Prosthetic Components and Design Flashcards
trim line
edges of the prosthetic socket
definitive prosthesis
the end product produced by the prosthetist
what is suspension? name the 5 main types
how the device is attached to the residual limb
suspension belts/cuffs, lanyard, pin-lock, suction and elevated vacuum
bench alignment
relationship among components set by prosthetist before customizations are made
What are the main 2 socket designs for transtibial amputations?
patellar tendon-bearing socket and total surface-bearing socket
Describe weight distribution of a patellar tendon-bearing socket.
it loads the patellar tendon and medial tibial flare (thus off-loading the fibular head and tender boney area. It also has a low post trim line for hamstring tendons.
Describe weight distribution of a total surface-bearing socket
more natural -feeling distribution of weight over entire residual limb to reduce shear forces. difficult to make correctly though
what are the 2 main types of transfemoral sockets?
quadrilateral and ischial containment
Describe structure of a quadrilateral socket.
four walls containing the thigh with the highest in the front vs back, posterior shelf for the glutes
Describe structure of a ischial containment socket.
covers ischial tuberosity with a wider A>P than M>L to resist extra femoral ABD, higher medial and posterior wall
what are the pros and cons of lanyard suspension?
pros: security, constant alignment, and doesn’t take up space at the bottom of the socket
cons: visible
what are the pros and cons of pin-lock suspension?
pros: secure, mechanical connection
cons: potential suction effect, difficult to align for deaf and blind, shuttle lock takes up socket space
what are the pros and cons of suction suspension? (think socket w/ rings)
pros: good fo rblood flow, very good suspension esp for fluctuating blood volume
cons: wear out liners quickly
what are the pros and cons of elevated vacuum suspension?
pros: comfortable and enables vol fluctuations
cons: heavy, must be charged, heavy coponent that takes up socket space
what are the 3 types of liners and what suspension types do they work best w/
silicone- pin-lock (soft, pressure-resist)
polyurethane-vacuum and suction (pressure absorption)
copolymer-total surface bearing (low activity)
Are socks the same as liner? where should they be worn?
NO, between the liner and socket to accommodate extra space
what is the order for applying components>prosthetic?
liner>sock>socket?prosthetic
what are the 4 types of prosthetic feet and the K levels they are associated with?
K1- SACH
K2:Single axis or multi axial
K3: Multi-axial
K4: hydraulic, multi-axial or crossover
Describe the single-axis, cushioned heel (SACH) foot
still and stable with limited energy return (req more effort>)
Describe the single-axis foot.
articulation joint for PF/DF
quick PF enable foot flat in initial contact and is good for TFA ** and user confidence
Describe the multi-axial foot.
enables PF/DF/INV/EV, split toe for uneven terrain, functional w/ good energy return
What is the function of the keel and what are the upstream effects it has on gait?
can be rigid flexible or dynamic to provide necessary stability. Impacts toe lever, heel rise/toe break of terminal stance, dictates knee flexion/stability
what are the 5 types of prosthetic knees?
polycentric, manual locking, pneumatic, hydraulic, micropressor
How do single axis and polycentric knees affect postural alignment? What does this require of the body?
It encourages GRFV to be anterior to the knee»body compensates with hip extension
Describe the manual locking knee.
it’s the most stable stance control knee but sacrifices knee flexion if not unlocked
describe hydraulic and pneumatic knees.
They use friction to control swing speed and adjust to user’s gait speed.
what are the benefits of hydraulic and pneumatic knees.
control on uneven surfaces
variable cadence and gait speed
mimics normal gait
describe the MOA and function of microprocessor knees
sensors measure joint angles, cadence,etc to provide stable and responsive knees for stance and swing phase control
what are the benefits of microprocessor knees
stumble recovery,stairs, power
