Week 9 Transtibial Socket Design/Ankle Foot Flashcards
Sach K1 Advantages
- Light weight, cost effective
- No moving parts, Low maintenance
- Durable
- Many Cosmetic options
- Endo or exoskeletal use
- Single speed household ambulators/ transfers
Sach K1 Disadvantages
- Heel cushion breaks down over time
- Minimal Energy return
- Not first choice for knee stability
Sach Indications
- early post operation
- Pediatric
- Permit pf in early stance and initiates extension moment at late stance
- Preparatory
Sach Contraindications
- Active patients
- When knee stability is needed
- can degrade over time
Single Axis K1-K2 Advantages
- promotes knee stability
- plantar flexion capability provides increased knee stability at heel strike
- May lessen difficulty of descending inclines
Single Axis K1-K2 Disadvantages
- requires service
- No inversion or eversion
- Adds weight and potential need for replacements
- High maintenance due to moving parts
- Less cosmetic/squeaks
- No energy return
Single Axis K1-K2 Indications
- anyone who needs a high level of knee stability
- Shock absorption at heel strike
Single Axis K1-K2 Contraindications
- Active patients
- controlling df and pf through bumpers/cushions to create a high level of knee stability not often used in TT- rarely necessary for TT amputees
Flexible Keel K2 Advantages
- Lightweight
- Flexible keel
- Multiaxial
- Shock absorption and energy return
Flexible Keel K2 Disadvantages
- Less durable
- Lower profile= less dynamic ability and may need additional knee stability
Flexible Keel K2 Indications
- household ambulator
- Outside limited to slow pace
Flexible Keel K2 Contraindications
- Not for K3 extremely active individuals
- Not for patient who need knee stability
Energy Storing/ Dynamic Response K3-K4 advantages
- Lightweight
- Durable
- Responsive
- little maintenance, no moving parts
Multi-axis K2-K4 Advantages
- Inversion/eversion
- PF and DF
- Shock absorption
- Torque absorption
Multi-axis K2-K4 Disadvantages
- Increased weight
- less durable
- maintenance required every 6 months
Multi-axis K2-K4 Indications
- Uneven terrain
- Transverse force reduction
Multi-axis K2-K4 Contraindications
- Weak patients
- Level surfaces ambulators
- Obese patients 90-130 pound weight limit
Hydraulic Benefits
- Moderate to high energy return
- Adjusts to varied surfaces
- smoother rollover ohase
Hydraulic Drawbacks
- expensive
- Slightly heavier
- Not as durable as other models
Total Contact Theory
- Pressure is distributed throughout the residual limb
- Less weight bearing on the patellar tendon
- All surfaces are in contact with the inner walls
- Not all parts of the residual limb are taking the load of the body weight
- Enhances venous return
Selective Loading Theory
- identifying areas of the residual limb that are tolerant or intolerant to pressure
- Load the more tolerant pressure areas
What are the pressure tolerant areas of the transtibial Residual Limb
- Patellar ligament
- Anterior compartment
- medial tibial flare
- Medial shaft of tibia
- Posterior compartment
- Lateral shaft of fibula
What are the pressure Intolerant areas of the Transtibial residual Limb
- Patella
- Lateral tibial flare
- Anterior tibial tubercle
- Crest of tibia
- Distal end of tibia
- Head of fibula and peroneal nerve
- Distal end of fibula
- Hamstring tendons
Patellar Tendon Bearing Socket
- One of the most common socket styles
- Counter balance forces to alleviate pressure over intolerant areas
-patellar tendon has both horizontal and vertical component of support - Can accommodate for fluid changes by using PTB and inner liner
Supracondylar Socket
- Socket has a higher medial and lateral walls that extend up and around the patella
- Adds medial and lateral stability and prevents hyperextension
Benefit/Drawbacks of the Supracondylar Socket
- benefit= helpful for those with short residual limbs or with knee instability
Drawback= higher profile socket creates an appearance that some amputees find cosmetically unappealing
Total Surface bearing Socket what does it do?
Expands on the total contact concept by distributing forces across the entire residual limb
- better sensory feedback
- Improved circulation
- Improved Proprioception
Pin Locking Benefits/Drawbacks
Benefits
1. ease of donning
2. Can adjust for volume changes
3. Auditory feedback that the pin engaged
4. Pin locks down in socket
Drawbacks
1. Can promote positioning/milking effect during swing
Sleeve Suspension Benefits
- uses a sleeve to maintain suction suspension
- Good visual feedback
- Basic design
Sleeve suspension drawbacks
- difficult for patient with poor hand dexterity or hand muscle weakness/wasting
- Sleeve damage will affect suspension
- Can be hot
- Can create restriction behind knee if not well donned
- problematic with frequent residual limb volume changes
Suction suspension what is it?
- A liner or valve
- air forced out of valve as patient pushes into socket creating suction
- Secure fit for better proprioception
- Minimizes pistoning
T/F the suction suspension adjust well to patient with volume changes
False
- suction suspension does not adjust well to patient with volume changes
Elevated Vacuum Suspension What is this???
- Intimate fit
- consists of a gel liner, suspension sleeve and air evacuation pump
- Creates negative pressure between the liner and the socket wall
- Improved proprioception
- Minimal limb volume fluctuation
- Improved blood flow
- decreases sheer forces
- motorized pump
Prosthetic socks need to be —- beyond the — of the sock
- 2 inches
- beyond
