KAFO

Question 1

L Trendelenburg =

Answer 1

• L side drops

- R weak hip ABD

Question 2

Why does a R trunk lean happen with L Trendelenburg?

Answer 2

• shortens hip ABD to a passive shortened position
• attempts to get pelvis close to level
• need clearance on L side

Question 3

When should a KAFO be considered?

Answer 3

there’s excessive movement of the knee that CANNOT be controlled with an AFO

Question 4

Knee in midstance: What are the muscles doing? (quads, hamstrings, gastroc)

Answer 4

• quads: firing to extend the knee
• hamstrings: trying to stabilize hip
• gastroc: eccentrically slowing down tibial translation

Question 5

What should be considered with the knee joint if we think the pt is going to go into a lot of hyperextension?

Answer 5

• should be able to bend/hinge to sit comfortably

- consider if we ned to offset

Question 6

offset

Answer 6

does the hinge need to be:

• inline
• anterior
• posterior

to the knee joint?

Question 7

What would you do with offset to correct hyperextension?

Answer 7

• should be neutral/inline

- the hinge will prevent hyperextension from happening

Question 8

Which patient population will likely need a KAFO?

Answer 8

• spasticity into hyperextension
• knee instability from weak quads (risk for buckling)
• hyperextending the knee on their own

Question 9

What are the types of knee joints for KAFOs?

Answer 9

• completely open/non-locking
• simple drop lock
• drop lock with ball bearing
• bail lock

Question 10

completely open joint

Answer 10

• single axis

- allows free movement

Question 11

Who would use a completely open joint?

Answer 11

spastic hyperextension caused by muscles (not by compensation)

Question 12

simple drop lock

Answer 12

• locks fall into place with sit «» stand

- requires manual locking

Question 13

Who would need a simple drop lock?

Answer 13

• someone at risk for buckling
• keep from compensating with hyperextension
• keeps them neutral throughout the gait cycle

Question 14

drop lock with ball bearing

Answer 14

• must be engaged by the patient (patient-assisted lock)

- able to do things with a free knee but can make it stable if needed

Question 15

Scenario where a drop lock with ball bearing would be a good choice

Answer 15

• post-polio: have good and bad days
• if we don’t strengthen it, they won’t get stronger
• need the stability when doing community ambulation

Question 16

bail lock

Answer 16

• when standing, a spring locks the KAFO in place

Question 17

Who might need a bail lock

Answer 17

• pt with limited dexterity

- can’t manually lock/unlock the joint