ORTHOTIC SYSTEMS

Knee-Ankle-Foot Orthoses (KAFOs)

KAFOs Designs Materials Uprights Joints Control

Components

KAFOs

Designs Metal Plastic Hybrid

KAFO Materials Metal KAFOs

Uprights Bands Joints Stirrups Leatherwork

KAFO Materials Plastic KAFOs

Thermoplastics Uprights Joints Straps

KAFO Uprights Aluminum

Lightweight Stainless Steel

Heavier but stronger

KAFO Knee Joints Free/limited motion Locking

KAFO Knee Joints Single Axis Free

Motion Controls

hyperextension When M-L control is

needed

KAFO Knee Joints Offset Free Motion

Axis is posterior Increased knee

extension stability

KAFO Knee Joints Polycentric Free

Motion Multiple axes of

motion More closely

approximates instantaneous axis of rotation in anatomical knee joint

KAFO Knee Joints Drop Lock

Metal ring drops over top of joint, preventing flexion

Simplest of locks

KAFO Knee Joints Bale Lock

Both locks are connected by metal hoop, or bale

Locks are disengaged by pulling bale up

Locks engage automatically when orthosis is extended

Metal KAFO Ankle Joints Free motion Dorsiflexion assist Double-action

Metal KAFO Ankle Joints Free/Limited

Motion ROM determined by

stirrup head shape

Metal KAFO Ankle Joints Dorsiflexion Assist

Posterior spring creates dorsiflexion moment

Metal KAFO Ankle Joints Double-action

Anterior & posterior channels allow for insertion of pins and/or springs to provide various combinations of ROM and assist

Plastic KAFO Ankle Joints

Free or limited motion

Variable motion

Plastic KAFO Ankle Joints

Tamarack Flexible with no

ROM control One variant can

produce dorsiflexion assist

DF Assist Neutral

Plastic KAFO Ankle Joints Oklahoma

More rigid than Tamarack with single axis of motion

No inherent ROM control

Plastic KAFO Ankle Joints ROM Controls

Molded into plastic at time of fabrication

Used in conjunction with previous joints to limit or influence ROM

Adjustable Stop

Dorsiflexion Assist

Plastic KAFO Ankle Joints Friddle Variable

Motion Allows fixed or

variable ROM Cannot be adjusted

on patient

Plastic KAFO Ankle Joints Camber ankle joint

Cams are installed to create limited ROM

One of several designs using interchangeable components to produce specific ROM

Plastic KAFO Ankle Joints Laminated foot

plate w/ stirrup Used when high

stress or activity is anticipated

Allows for use of metal ankle joints

KAFO Control components Supra/Infra Patellar

Pads Generates

extension moments above and below knee axis

KAFO Control components Full knee control

pad/strap Generates

extension moment over patella which is actually above knee axis

May have flange (shown) to provide M/L control

KAFO Control components Adjustable extension

component Position of serrated ring

over serrated disc determines point of full extension

Useful for knee flexion tightness/contractures

KAFO Control components Quad/Narrow M-L Brim

Provides method to un-weight knee and distal extremity during stance phase

KAFO Control components Hip joints/Pelvic band

Created increased hip and trunk stability

Some designs generate a reciprocating action to produce a swing-through gait