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