Week 2 Flashcards
What are the below knee pressure tolerant areas?
Patellar tendon
Medial tibial plateau
Tibial and Fibular shafts
Distal end (rarely, maybe sensitive)
What are the below knee pressure sensitive areas?
Anterior tibia
Anterior tibial crest
Fibular head and neck
Fibular nerve
What are the Transfemoral pressure sensitive areas?
Distolateral end of the femur
Pubic symphysis
Perineal area
What are the Transfemoral pressure tolerant areas?
Ischial tuberosity
Gluteals
Lateral sides of the residual limb
Distal end (rarely, may be sensitive)
Who is the patellar tendon bearing socket indicated for?
Previous wearer
Extreme Atrophy
Selective hot spots - neuromas, callusing
What is the total surface bearing socket?
Even distribution of pressures
Total contact fit
Who is the total surface bearing socket indicated for?
Majority of patients
Mild to moderate Atrophy
Patients with skin conditions or considerations
Unstable volume or edema
What are the coronal plane forces?
Fulcrum at MTP
Distal lateral forces
Proximal medial forces
Loading pressure tolerant areas
What are the sagittal plane alignment forces?
Proximal posterior
Anterior pre-Tibials
Proximal anterior
Patellar tendon
What are the biomechanical goals?
~Maximize the weight-bearing capacity of the residual limb
~Provide ML stability at Mid-Stance on the prosthetic side- modification of dynamic forces
~Encourage knee flexion throughout stance phase- modification of dynamic forces.
What is pressure?
Pressure= force/area
Even distribution of forces is key
Inclination of forces?
Loads pressure tolerant anterior surface
Encourages knee flexion at heel strike
Prevents knee hyperextension
What is the purpose of total contact?
Minimize edema
Increase proprioception
Improve weight bearing
Is the floor reaction line medial or lateral to the knee joint (NHL)?
Medial
What moment is created at the knee at mid-stance?
Varus moment
Prosthetic alignment: foot initially inset at _____mm (medial)
12mm
Excessive Varus moment is caused by?
Increased distal-lateral and proximal-medial pressure
Insufficient Varus moment is caused by?
Valgus moment
Proximal-lateral and proximal-medial pressure
When distal-lateral and proximal-medial are loaded base of support is ____________.
Narrowed
Decrease in energy expenditure
Loads pressure tolerant areas and relieved pressure sensitive areas
Effects on forces:
Increase mass»_space; ___________ force on limb
Increase inset»_space; ____________ force on limb
Increase limb length»_space; ___________ force on limb
Increase trim lines»_space; ____________ force on limb
Increase
Increase
Decrease
Decrease
Prosthetic alignment: initial foot placement at ____posterior to ankle bolt. Foot is dorsiflexed, socket is aligned with _____degrees of flexion and proper heel stiffness
37 mm
10 degrees
Excessive knee flexion at early stance is caused by?
Heel too firm, foot too DF, excessive socket flexion, foot too far anterior, heel too high, shoe too tight, keel too soft.
Knee hyperextension at late stance is caused by?
Foot too far anterior, foot too PF, inadequate flexion of socket, heel too soft, keel too stiff
Premature loss of anterior support at late stance (drop off): is caused by?
Foot too far posterior, foot size too small, keel too soft
What are the modes of suspension?
Joint and Corset suspension Belt or cuff suspension Compressive sleeve suspension Anatomical- Suction/ Expulsion valve suspension Elevated vacuum
Joint and Corset is indicated for?
Incorporates thigh weight bearing
Improves ML stability
Heavy duty user
Patient preference
What are the advantages of the Joint and Corset?
Increases weight bearing surface
Unloads the residual limb
Increases ML stability
Knee extension control
What are the disadvantages of the Joint and Corset?
Heavy
Un-cosmetic
Inherent pistoning
Who is the supra-condylar cuff indicated for?
Many of TT users prefer
Patients with stable ligaments
Juvenile patients
Long residual limbs
What are the advantages of the supra-condylar cuff?
Provides good suspension over patella
Adjustable
Can be used in combination with waist belt
What are the disadvantages of the supra-condylar cuff?
Can be restrictive
Does not increase ML stability, un-cosmetic
Who is the sleeve suspension indicated for?
Many of TT users prefer
Patients with stable ligaments
Juvenile patients
Long residual limbs
What are the advantages of sleeve suspension?
Provides excellent suspension
Conceals trim lines
Variety of materials available
What are the disadvantages of the sleeve suspension?
Can cause skin problems
Can increase perspiration, hard to don
May not be indicated for vascular patients
Who is the supra-condylar and patellar suspension indicated for?
Patients with very short residual limbs
Patient requiring ML stability
Patients who want less straps
What are the advantages of supra-condylar and patellar?
Increase weight bearing surface
Improved ML stability
Improves cosmesis
What are the are the disadvantages of supra-condylar and patellar?
Can inhibit some motion and activity
Difficult to use on obese or muscular
Who is supra-condylar suspension indictated for?
Patients with very short residual limbs
Patients requiring ML stability
Patients who want less straps
What are the advantages of supra-condylar suspension?
Less restrictive than PTB-SC
Improved cosmesis
What are the disadvantages of supra-condylar suspension?
Loss of rigid hyperextension stop
Difficult to use on obese or muscular
Who is the silicon suction indicated for?
Patients with good subcutaneous tissue
Full function of upper extremities
Want less straps
What’s the advantages silicon suction?
Excellent suspension
Eliminates pistoning
Increased proprioception
Good torque absorption
What are the disadvantages of silicon suction?
Can be difficult to don
Good hygiene is required
Who is vacuum and suction suspension indicated for?
Patients with good subcutaneous tissue
Patients who wants less straps
Patients who can’t tolerate distal pulling from a lock and pin
What are the advantages of vacuum and suction Suspension?
Excellent suspension
Eliminates pistoning
Increased proprioception
What are the disadvantages of vacuum and suction suspension?
Maintenance is required
Can loose vacuum
Can be complicated to use for some
Shock absorbers and Rotational units are indicated?
Torque absorption
active users
Special situations and activities
Who is the SACH feet indicated for?
Many lower limb users
Juveniles
What are some contraindications of the SACH feet?
Active individuals
When knee stability is required
When inversion/eversion is required
What are the advantages of the SACH feet?
Cosmetic
Quiet
Little maintenance
What are the disadvantages of the SACH feet?
Deterioration of soft materials
No torque absorption
Who is the single axis prosthetic feet indicated for?
Patients needing knee stability
What are the contraindications of the single axis feet?
Many lower limb users
Active users
When torque, inversion or eversion is needed
What are the advantages of the single axis feet?
More shock absorption
Promotes knee stability
What are some disadvantages of the single axis feet?
No torque absorption
Requires bumper replacement
What are the indications for the multi-axis feet?
Torque absorption needed
Special activities
Need for in/eversion
What’s a contraindication for the multi-axis feet?
When other components can be used
What are the Advantages of the multi-axis feet?
Absorbs torque, shock
Foot conforms to surfaces
What are the disadvantages of the multi-axis feet?
Cosmesis, increased weight
Increased maintenance
Who is the dynamic response feet indicated for?
Active ambulators
Community ambulators
What’s a contraindication of the dynamic response feet?
One speed ambulators
What are the advantages of dynamic response feet?
Smoother gait, less energy expenditure
Light weight, cosmetic, energy storing
What’s the disadvantages of the dynamic response feet?
Materials durability, limited sizes, expense
Who is the multi-axis dynamic response feet indicated for?
Active users, varying cadence ambulators
Community ambulators, athletes
What’s a contraindication of the multi-axis dynamic response feet?
Single speed ambulators
What’s the advantages of the multi-axis dynamic response feet?
Multi-axial capabilities, dynamic response
Energy storing capabilities
What’s the disadvantages of the multi-axis dynamic response feet?
Expense
Maintenance
What’s an indication of the external power prosthetic feet?
Potentially, all mildly active ambulators
What are some contraindications of the external power prosthetic feet?
K1 level ambulators
Wet or corrosive environments
What’s the advantages of the external power prosthetic feet?
Anatomical power and propulsion
Anatomical limits for PF and DF
What are the disadvantages of the external power prosthetic feet?
Batteries, weight , cost
Processing speed
Limited environment use
What are the trans-tibial gait deviations?
Inadequate flexion or extension Medial or lateral leaning pylon Drop off Erratic movement Heel lever and toe lever Whips
