Prosthetic Feet

Question 1

Non-Articulating SACH Foot

Answer 1

• solid ankle cushioned heel
• commonly prescribed
• simple
• low cost
• no articulations
• relies on cushioned heel to control initial to foot flat
• best for level ground and limited community ambulators

Question 2

Articulating Design

SIngle Axis and Multiaxial Feet

Answer 2

• foot that allows for plantar and DF via some mechanism of bumpers and an axis pin
• stimulates actions of the gastroc/soleus and anterior tib
• reduces flexion torque at the knee at initial contact
• advantages
  
  • reduced torque on knee and therefore decreased pressure on residual limb
  • accommodates uneven terrain
• Disadvantages
  
  • weight, mechanical complexity, noisy, cosmesis
• Single Axis
  
  • primary advantage - able to reach foot flat position quickly in early stance
• Multi Axis
  
  • gressinger foot
  • college park foot
  • endolite multiflex foot
  • advantage = foot can accomodate uneven terrain >1 plane
  • requires strength and regular maintenance

Question 3

Prosthetic Feet with Elastic Keel

SAFE Feet

Answer 3

Standard Attachment flexible endoskeletal = SAFE

• advantage = smother gait pattern and higher functioning foot with less maintenance or weigh relative to articulated foot
• disadvantage = may feel spongy to some and not stiff enough to active/athletic individuals

Question 4

Dynamic Response or Energy Storing Designs

Seattle Foot, Flex foot

Answer 4

Seattle

• released in early 1980s and was considered a dynamic response foot
• absorb and store forces during loading and then release this energy during push off

Flex Foot

• variations
• good for engaging in high demand activities
• more energy efficient
• but have higher cost and not for weaker pt

Springlite foot

• dynamic response foot

Question 5

Energy Return Percentages

Answer 5

• SACH = 0%
• Seattle = 70%
• Flex = 90%
• Human = 260%