WK9- TT Componentry and Feet Flashcards
Regarding TT prosthetic fitting, what are some general concepts ?
Intimate fit of the socket to the residual limb
decrease skin breakdown and forces
alignment to promote best gait
What are the basic components that make up a prosthetic ?
Feet, ankles, shock pylons, sockets
What forces should you aim to reduce with prosthetic fitting ?
shear, friction, rotation, axial forces
Define the total contact theory
pressure is distributed throughout the residual limb, less weight bearing on the patellar tendon,
Define the selective loading theory of weight distribution
There are specific areas of the residual limb that are tolerant and intolerant to stress. Load the more tolerant areas.
What are some pressure tolerant and intolerant areas ?
tolerant: patellar lig, anterior compartment, medial tibial flare, medial shaft of tibia, posterior compartment
intolerant: patella, lateral tibial flare, anterior tibial tubercle, crest of tibia, distal end of tibia, head of fibula and peroneal nerve, distal end of fibula.
Briefly describe a patellar tendon bearing socket
one of most common socket styles
counter balances forces to alleviate pressure over intolerant areas
horizontal and vertical support component
can accommodate volume changes by using a pelite liner
Describe a supracondylar socket
high medial and lateral walls that enclose the patella
mediolateral stability
grips the femoral condyles
benefits: helpful for those with shorter residual limbs or knee instability
drawbacks: high profile, patients may think it ugly
What is a suspension ?
coupling between residual limb and prosthesis
List some common suspension mechanisms
Silesian Belt
Thigh Corset
Cuff Strap
Pin Locking
Sleeve Suspension
Suction
Elevated Vacuum Suspension
Which suction mechanism uses a rod that clicks into the prosthetic
pin locking
What is the thickest ply of prosthetic sock available /
6
At what ply of socks should you consider a prosthetic replacement
> 10
What are some factors to consider when selecting a prosthetic foot ?
functional level, ADLs, work, K class
body weight
residual limb
severity of comorbidities
environmental exposure
shoe choices
interaction with other components
prior feet/gait habits
psychology and character
skin tone
B/L limb loss
What K level is a SACH advised for ?
house hold ambulators, K1
Briefly describe the advantages and disadvantages of a SACH.
advantages: durable, cost effective, lightweight
disadvantages: heel cushion breaks over time, no energy return, not first choice for knee stability
What populations are indicated and contraindicated for a SACH?
indicated for:
early post op, pediatric, preparatory,
contraindicated for:
active patients, when knee stability is needed
How does a SAFE foot differ from a SACH ?
the SAFE foot has a plantar ligament for a smooth transition during toe off
What K level is a single axis foot advised for ?
K1-K2
What are the advantages and disadvantages of a single axis foot ?
advantages: promotes knee stability, easier to descend declines
disadvantages: no inversion or eversion, requires service because of moving parts, adds weight, no energy return
What are the indications and contraindications for a single axis foot ?
indications: anyone who needs knee stability, shock absorption at heel
contraindications: active patients
What K level is advised for a flexible heel ?
K2
What are the advantages and disadvantages of a flexible keel ?
advantages: flexible keel, multiaxial, lightweight
disadvantages: less durable, low profile
What are the indications and contraindications for a flexible keel ?
Indications: household ambulator, outside limited
contraindications: not for K3, active individuals, not for knee stability
What K level is advised for energy storing or dynamic response prosthetic ?
K3-K4
What are the advantages and indications of a energy storing or dynamic response prosthetic ?
advantage: responsive, durable, little maintenance
indications: athletes, patients who walk with variable cadence, active patients
What K level is a multi axis prosthetic indicated for ?
K2-4
What are the advantages and disadvantages of a multi-axis prosthetic ?
advantages: inversion, everion, pf, and df; shock and torque absorption
disadvantages: increased weight, less durable, maintenance required
What are the indications and contra indications of a multiaxis prosthetic ?
indications: uneven terrain, transverse shock reduction
contra: weak patients, level surfaces ambulators, obese patients
What are the benefits and drawbacks to a hydraulic foot ?
benefits: moderate to high energy return, adjusts to surfaces, smoother rollover phase
drawbacks: expensive, heavy, not as durable
What are the pluses and minuses of microprocessor feet ?
actively responds to environment changes, heavier, battery needs nightly recharging, limited to single axis
containdicated for: very high activity, heavy body weight, water dirt or sand, temperature extremes.
