Orthotic Manufacturing

Question 1

what position is the calcaneal bisection as the positive is made

Answer 1

perpendicular to the ground

Question 2

when i the negative cast removed

Answer 2

when the plaster is hardened

Question 3

what are the types of positive plaster modifications

Answer 3

• FF platform
• heel cup accommodation
• arch fill
• “sweet” spots

Question 4

how is a FF platform created

Answer 4

• nail is placed on the plantar sufrace of the 1st (for FF varus) OR 5th (for FF valgus) MT head to prop up the positive in the appropriate position
• plaster is applied to build a platform at an angle dictated by the position of the nail

Question 5

where is the calcaneal bisection when forming a FF platform

Answer 5

-perpendicular to the ground or FF may be “balanced” to RF

Question 6

for a FF varus, where will the FF platform me thicker

Answer 6

medially

Question 7

fore a FF valgus, where will the platform be thicker

Answer 7

laterally

Question 8

how is a heel cup accommodation added

Answer 8

plaster is added around the periphery of the heel

Question 9

what does a heel cup accommodation allow for

Answer 9

-soft tissue spread when the patient bears weight

Question 10

where are arch fills added

Answer 10

to the medial arch to allow for soft tissue expansion and to provide a smooth transition into the FF platform

Question 11

a minimal arch fill will provide for

Answer 11

greater control

Question 12

a heavier arch fill will allow for

Answer 12

more flattening of the arch

Question 13

how do you accommodate for “sweet spots”/bony prominence

Answer 13

add a small mound of plaster to the area of the prominence which will then lead to a pocket on the shell

Question 14

what are the material requirements for the shell

Answer 14

heat moldable

able to hold their shape

Question 15

where does a standard functional device extend to

Answer 15

• just proximal to the MT heads distally
• to the centre of the 1st MT medially
• to the centre of the 5th MT laterally

Question 16

is the device width dependent upon foot width

Answer 16

no!

Question 17

the wider the device the —

Answer 17

greater the control

Question 18

the width of the device is highly dependent upon

Answer 18

the type of shoe in which the device will be work

Question 19

a wide device extends from

Answer 19

the medial side of the 1st MT head to the lateral side of the 5th MT head

Question 20

a normal device extends from

Answer 20

the centre of the 1st to the centre of the 5th

Question 21

a narrow device extends from

Answer 21

the lateral aspect of the 1st MT head to the medial aspect of the 5th MT head

Question 22

where is an extrinsic RF post applied to

Answer 22

the shell

Question 23

is an extrinsic post the same thing as a heel lift

Answer 23

No!

Question 24

how do functional devices work

Answer 24

• prevent excessive pronation
• allow the STJ to function around its neutral position
• prevent compensation

Question 25

what are 3 functional device theories

Answer 25

1. pre-positioning of the foot 2. proprioceptive facilitations 3. altering the extrinsic moments

Question 26

pre-positioning of the foot means that

Answer 26

- STJ neutral position - MTJ maximally pronated (locked) position b/c that is the ideal position of the foot in the middle of midstance as it prepares for the propulsive phase of gait

Question 27

what phase of gait do most pathologies occur

Answer 27

propulsive phase

Question 28

functional orthosis generally cannot control the motion of the foot during the propulsive phase, why?

Answer 28

-b/c so little of the foot (only the MT heads) is actually weight bearing

Question 29

how do functional orthosis help control motion of the foot

Answer 29

- by placing the foot in an optimum position as it enters the propulsive phase - theoretically, the deleterious stresses will be minimized

Question 30

how can orthoses prevent excessive pronation

Answer 30

- providing increased proprioceptive clues - allowing the patient to respond to the rate and amount of pronation more appropriately - the more direct contact you have on the plantar surface, the more cues you have about where your body is in space

Question 31

what is posting

Answer 31

- bringing the ground up to the deformity | - eliminating the need for compensation

Question 32

arch support provides for

Answer 32

- increased proprioceptive feed back | - allows for a surface in which posting may be used

Question 33

does posting bring the ground up to the MT heads

Answer 33

NO! | Functional orthosis does not control MT head contact to the ground

Question 33

how are osseous restraining mechanisms optimized

Answer 33

-by placing the foot in a more stable position

Question 33

which part of the orthosis help prevent excessive pronation

Answer 33

- distal medial shell - anterior medial edge of the RF post - "anti-pronatory" pressure (extrinsic supinatory moment) at the distal medial calcaneal tuberosity (as determined by the contour of the heel cup)

Question 34

a deep heel cup provides for ---- compared to a lesser heel cup

Answer 34

greater control

Question 35

do functional orthosis function as an arch support

Answer 35

NO! | The arch area of the device is not a component to control pronation

Question 35

heel cup helps control

Answer 35

- STJ motion | - minimize the amount of calcaneal inversion and eversion

Question 35

control of the lateral column provides for

Answer 35

increased stability of the foot