S2 L8: Knee Ankle Foot Orthosis (KAFO)

Question 1

What consists in a KAFO?

Answer 1

Shoe, foundation, ankle control, knee control, and higher superstructure.

Question 2

KNEE CONTROL: Hinge-placed posterior to the midline of the leg (posterior to TKA line)

Answer 2

Off-set Joint

Question 3

On an Off-set Joint Orthosis, the pt assumes knee extension which will automatically ____?

Answer 3

Stabilize the knee and makes standing posture more stable.

Question 4

On an off-set Joint Orthosis, the patient’s weight line falls anterior to the off-set joint, stabilizing the knee in extension during when?

Answer 4

Early Stance Phase of gait when wearer is on a level surface.

Question 5

T/F: Off-set Joint orthosis does not hamper knee extension during swing or sitting.

Answer 5

False. Does not hamper knee FLEXION during swing or sitting.

Question 6

Why can the Off-set Joint orthosis cause knee buckling or let the joint flex inadvertently when walking on ramps? And what can you do to combat it?

Answer 6

1. Because it only stabilizes during knee extension.
2. Prescribe strengthening exercises for the knee muscles (hamstrings) to provide adequate stability during knee flexion.

Question 7

Most common knee control with manual control at proximal uprights.

Answer 7

Drop-Ring Lock

Question 8

Using a Drop-Ring Lock, what happens when the patient stands with the knee fully extended?

Answer 8

The ring drops preventing the uprights from bending.

Note: You can manually control/remove the lock to do knee flexion

Question 9

What is the contraindication for Drop-Ring Lock knee control?

Answer 9

Contraindicated for Knee Flexion Contracture

Question 10

Knee control that provides simultaneous locking o both uprights.

Answer 10

PAWL Lock with Bail Release

Question 11

PAWL Lock with Bail Release Mechanism
1. R Leg, R dominant
2. R leg, L dominant

Answer 11

1. Put it on the lateral upright
2. Put it on the medial upright

Question 12

How to use the PAWL Lock with Bail Release (How to unlock brace)

Answer 12

Patient unlocks the brace by pulling upward on the posterior bail and allow knee flexion

Question 13

PAWL Lock with Bail Release: If the wearer is jostled against a rigid object, _____?

Answer 13

The bail is bulky and may release the lock unexpectedly. This is a risk of knee

Question 14

PAWL Lock with Bail Release: When does it automatically lock and what do you do after?

Answer 14

1. When the knee is 0 degrees
2. When walking, manually pull the bail upwards

Question 15

Knee Control that is prescribed for patients who cannot achieve full knee extension due to knee flexion contracture

Answer 15

Serrated Knee Joint

Question 16

Knee Control that applies a posteriorly directed force to complement the anteriorly directed forces from the back of the shoe and the thigh band.

Answer 16

Knee Cap

Question 17

A Knee Cap knee control orthosis restricts what action?

Answer 17

Sitting. Anterior force can cause knee flexion

Question 18

Knee control primarily indicated for pediatrics that are shaped to apply corrective force for genu valgum or genu varum

Answer 18

Frontal Plane Control

Question 19

For Frontal Plane Control: How to reduce Genu Valgum?

Answer 19

The medial portion of the shell extends proximally in order to apply laterally directed force at the knee.

Question 20

In KAFO Superstructures, if the distal portion of the limb cannot tolerate FWB, what does the proximal thigh band do?

Answer 20

It may be shaped to form a WB brim. An with assist with a locked knee joint and a pattern bottom, it can deload the LEs.