Please enable JavaScript.
Coggle requires JavaScript to display documents.
Lower Extremity Orthotics (Knee Ankle Foot Orthotic (KAFO) (Conventional…
Lower Extremity Orthotics
Effectiveness & Comfort
3 or 4-point systems of force necessary to correct posture
Orthotic forces: distributed over large surface areas to minimize local skin a ST pressures
applied using larger moment arms possible/practical
Sum of primary and counter forces of each control system = 0
Ankle Foot Orthoses (AFO)
Static Orthoses: Prohibit motion in any plane at the ankle
Solid Ankle AFO
Action: control ankle position throughout stance; stability; assist limb clearance in swing; position for for IC by heel; distal trim line behind MT heads
Indications: Significant hypertonicity with seriously impaired motor control @ ankle & knee
Contraindications: LMN paralysis (flaccidity) or hypotonicity
Anterior Floor Reaction AFO
Actions: Provide stability in stance via ankle-knee coupling; Control ankle position throughout stance
Indications: Weakness or impaired motor control @ ankle & knee
Contraindications: Ligamentous insufficiency at the knee, Genu recurvatum
Weight-relieving AFO
Actions: Protect lower leg and foot during stance by reducing WB forces
Indications: Healing ST, ligamentous or bone injuries of lower leg, ankle, or foot
Contraindications: Mechanical instability of the knee, or injury to prox tibia; Patient intolerance of PTB weight-bearing forces (rare)
Dynamic Orthoses: Allow some deg of sagittal plane motion at the ankle
Posterior Leaf Spring AFO
Actions: Assist limb clearance in swing; Preposition foot for IC by heel
Indications: DF weakness, impaired motor control, LMN flaccid paraylsis of DFs
Contraindications: Mod-severe hypertonicity
Articulating Ankle AFO
Actions: Assist limb clearance in swing; Preposition foot for IC; Permit adv of tibia in stance
Indications: Impaired motor control of ankle musculature; Potential for recovery of neuromotor function
Contraindication: LMN paralysis or hypotonicity as primary problem
Knee Ankle Foot Orthotic (KAFO)
Considered only when stability during stance cannot be effectively provided by AFO
Presence of hyperextension or recurvatum that jeopardize structural integrity of knee joint
Abnormal or excessive varus or valgus angulation during WB in stance phase
Evidence of ligamentous instability that threatens A/P or Med/Lat stability at the knee
Stance-Control (SC) knee design
Improved function & energy cost
Alters GRF at hip, creating extensor moment that enhances stability
Conventional KAFOs
Advantages
Strong, Most durable, Easily adjusted
Disadvantages
Less cosmetic, Heavy, Must be attached to shoe/insert
Fewer contact points reduce control
Indications
When max strength and durability are needed
Significant obesity
Uncontrolled or fluctuating edema (ie. CHF)
Craig-Scott orthosis
lightweight variation of traditional KAFO
Design to maximize stability in stance w/minimal amount of bracing
For persons with paraplegia after thoracic level SCI
Frequently used to preserve upright mobility for children with DMD (muscular dystrophy)
Thermoplastic KAFOs
Advantages
Lightweight
Interchangeability of shoes
Greater cosmesis worn under clothing
Force application distributed over larger surface area = more precise and comfortable control of the limb
Disadvantages/Contraindications
Can be hot to wear
Significant obesity
Uncontrolled or fluctuating edema
Indications
Intimate/total contact fit makes maximum limb control possible
better energy expenditure due to increased surface area and dissipation of 3-point force systems
Control of transverse plane motion needed