Foot Orthoses - AFO

Question 1

foot orthoses attempt to alter the

Answer 1

gound reaction force

Question 2

In order to use Custom Foot Orthotic CFO you must be convinced that…

Answer 2

• GRF can be altered through external devices
• Foot can help dictate where the GRF vector is positioned
• Atypical function affects position of GRFV and LE alignment
• Together, and over time, atypical function may result in musculoskeletal pathology

Question 3

How do CFO work in mgmt of foot and LE pathologies?

Answer 3

they don’t stop the amount of motion, but control the ground reaction forces

Question 4

goals of foot orthotics

Answer 4

• control GRF and thus ROM (amount and rate)
• redistribute pressure
• reduce shock
• reduce friction
• stabilize and support

Question 5

CFO theory - Subtalar Joint Neutral theory (AKA root theory), goal?

Answer 5

• Goal is to restore STJ to a neutral position
• Is base on premise that structural deformities cause abnormal movement and compensations
• Old theory, the field is moving away from

Question 6

CFO theory - Tissue Stress Model goal

Answer 6

• goals is to reduce or alter forces that are detrimental
• looks at tissue stress based in an understanding of biomechanics

Question 7

this CFO theory suggests that location, type, and magnitude of force are what produce foot dysfunctions

Answer 7

Tissue Stress Model

Question 8

steps to prescribe a CFO according to the tissue stress model

Answer 8

1. Identify source of complaint
2. Identify forces producing atypical stress (too large? too repetitive? can the structure handle the forces?)
3. determine structural characteristics of the foot through gait, physical exam, and Hx.
4. Determine other variables also responsible: type of shoes, trauma?
5. Design a CFO to reduce stress, optimize gait and function, and do not produce new symptoms.

Question 9

the design of the CFO is to

Answer 9

direct the Orthosis Reaction Force

Question 10

what is the Orthosis Reaction Force?

Answer 10

Ground reaction force is transmitted to the foot orthotic, and the the foot orthotic alter the location and magnitude of the GRF and thus apply an Orthosis Reaction Force

Question 11

categories of FO

Answer 11

• Functional: change motion, prevent compensations and excess motion
• Accommodative: comforts the foot for deformities and distributes forces
• Combination devices

Question 12

types of FO

Answer 12

• Prefrabricated
• Customized

Question 13

a soft material CFO funtion

(plastazote, pelite, aliplast, spenco, rubber, PPT, silicone felt)

Answer 13

shock absortion and relief of pressure

Question 14

a semiflexible material CFO function

(leather, cork, plastazote, EVA)

Answer 14

support, control, and shock absortion

Question 15

a rigid material CFO function

(harder plastics, metals, alloys, carbon graphite)

Answer 15

control

Question 16

a pt has a custom foot orthosis made of Aliplast, this material will facilitate:
A. Support, control, and shock absorption
B. Shock absortion and relief of pressure
C. Control of movement
D. Relief of pressure and and support

Answer 16

B.

Question 17

foot modeling for the fabrication of CFO can be

Answer 17

• impression casting
• laser scans

Question 18

plantar fascitis orthotic

Answer 18

Question 19

orthotics for pain in the balls of the feet (metatarsalgia)

Answer 19

domes, pads, teardrops

Question 20

orthosis for neuroma

Answer 20

• neuroma pad placed:
  
  • intermetatarsal space
  • metatarsal shaft

Question 21

leg length discrepancy

Answer 21

heel lifts

Question 22

heel lift, more than a 1/4 of an inch?

Answer 22

use shoe lift

Question 23

University of California Biomechanics Laboratory - Talus containment orthotic is good for…

Answer 23

• flexible pronation
• holds foot in neutral
• not good for rigid foot
• no long-term effect

Question 24

causes of orthotics failure

Answer 24

• Poorly performed/no biomechanical eval
• Improper or inappropriate casting
• Inappropriate materials
• Inappropriate prescription
• Improper shoes/shoe wearing habits