Foot Function + Orthoses

Question 1

Describe a way to measure static foot alignment/posture

Answer 1

The Foot Posture Index

• scores someone according to how pronated/supinated they are
• negative = supinated/positive = pronated

Question 2

Does static measure predict dynamic function?

Answer 2

• FPI might predict rearfoot motion (not strongly) - but not midfoot
• therefore both static AND dynamic is needed

Question 3

Can you prescribe a shoe or orthotic based soley on plantar pressure measurements? Why or why not?

Answer 3

No:

• foot structure and function predicts for only 50% of plantar pressure variables
• does not measure 3D function of the foot

Question 4

Whats the benefits of using plantar pressure measures?

Answer 4

• great to measure how much pressure a particular area of the foot is experiencing
• good for diabetics (ulcers), painful cavus feet

Question 5

What are the 4 ways in which you can influence foot motion and function?

Answer 5

1. influence pronation/supination forces
2. influence arch lowering forces
3. reduce pressure
4. accommodate loss of range

Question 6

What influences the pronation/supination forces and descrbe a clinical test you can use to find this

Answer 6

The STJ axis

• using thumb to stabilize the 5th MT - place the other thumb on the heel and find the point where pressure doesnt cause the foot to go into supination or pronation
• do this all the way up the foot and mark the points along the way
• this is your STJ axis!

Question 7

Using a wedge to post the posterior rearfoot in valgus - what effect would this have to:

• internal sup force
• external sup force
• pronation
• external pronation moment

Answer 7

• would reduce internal sup force
• would increase external sup force
• would reduce pronation
• would reduce external pronation moment

Question 8

By reducing pronation - give 2 examples of structures that you might de-stress:

Answer 8

1. tib post
2. sinus tarsi - since compression of this area is poss with excess pronation, relieving pronation can reduce stress on this area
3. patellofemoral pain - due to increased adduction of knee joint, IR of femur?

Question 9

How does an orthotic work to help with plantar fascia pain?

Answer 9

• the plantar fascia supports medial longitudinal arch
• orthotics provide mechanical arch support thereby offloading the PF
• prefab is just as effective as custom for effectiveness

for PLANTAR HEEL PAIN - valgus wedging can reduce pressure on plantar fascia

Question 10

How can arch support help with dorsal midfoot interrosseous compression sydnrome

Answer 10

Would prevent excess flattening of the foot which would compress the bones of midfoot.

Question 11

Describe the effect of a lateral wedge on:

• internal and external moments
• knee adduction moment

Answer 11

A lateral wedge (valgus wedge):

• increases pronation
• reduces internal pronation moment
• increase external pronation moment
• reduces knee adduction moment by moving the shank and knee closer to the vector of the GRF

Question 12

What might orthoses be effective for?

Answer 12

PHP
RA
Painful cavus feet
PFP