Lower Extremity Orthoses (FO and AFO)

Question 1

What are the purposes for orthotic prescription?

Answer 1

-improve performance of functional activities
-improve/enhance mobility (transfers/ambulation)
-deformity prevention
-correction of passivley modifiable deformity
-immobilization/control/prevention
-regulate or reduce muscle tone
-stabilizing weak or flaccid muscles
-improve quality of life

Question 2

What are the purposes of foot orthoses (inserts)

Answer 2

-alignment correction
-deformity accommodation
-facilitate supination/pronation
-pain relif
-improve foot and/or proximal alignment
-relieve WB stresses

Question 3

What are 2 types of deformities/contractures?

Answer 3

Fixed: cannot be passively corrected
Flexible/Dynamic:
-result from over activity of muscle tendon groups but when at rest are passively correctable
-can also develop adjacent joints in response to coupling effects of deformities above/below

Question 4

What are 2 types of FO fabrication?

Answer 4

Pre-fabricated (off the shelf)
-generic fit, good for short term use (healing, function/training aid, contracture prevention)
-typically cheaper

Custom (definitive)
-permanent benefit is needed
-mechanically and physiologically stable
-individualized to patient

Question 5

FO Length types?

Answer 5

Full length: extend to toes
Sulcus: proximal to toes
3/4: met heads

Question 6

Types of FO flexibilities?

Answer 6

Soft
-provides cushion, shock absorption, redistribute plantar pressures

Semi-rigid
-provides some flexibility and shock absorption
-provides control of the foot

Rigid
-stabilizes deformities
-controls abnormal motion
-provides support

Question 7

What needs to be documented for FOs?

Answer 7

-length
-flexibility
-fabrication method

Question 8

When are FO’s indicated for use?

Answer 8

-abnormal medial longitudinal arch
-leg length discrepancy
-rearfoot amlaignment
-diabetic foot

Question 9

Abnormal medial longitudinal arch

Answer 9

Pes planus
-if flexible, can be correct with FO
-posterior tibialis supports arch

Pes cavus
-support deformity

Question 10

Leg length discrepancy

Answer 10

-caused by previous injury to leg, bone infection, congenital, idiopathic
-Normal: up to 3/5 inch
-1 2/3 inch difference will result in gait abnormalities
-use heel lift or shoe lift

Question 11

Rearfoot malalignment

Answer 11

Rearfoot varus
-use medial wedge to accommodate (decrease hyperpronation)

Rearfoot valgus
-use lateral wedge to accommodate (decrease supination)
-medial wedge to correct

Question 12

Diabetic Foot

Answer 12

-increased risk for skin breakdown
-FO provide pressure relief
Rocker shoes
-decrease forefoot pressure
-facilite forefoot rocker

Question 13

What are the purposes for AFOs?

Answer 13

-provide ankle stability
-correct malalignment
-control drop foot
-enhance mobility
-deformity prevention
-regulate or reduce muscle tone

Question 14

How to prescribe an orthotic device?

Answer 14

1. Identify where in the gait cycle abnormal tone or muscle performance is impaired. Where is the gait deviation?
2. Determine what factors can be compromising the particular abnormal phase of gait
3. Identify what specific orthotic intervention would benefit the particular abnormal phase of gait cycle
   *AFOs can be worn by many patients who can walk without them, however walking with them makes them safer and more efficient

Question 15

What does AFOs provide during swing phase?

Answer 15

-external support during swing (position of ankle/foot) for foot clearance
-Optimize position of the limb for initial contact in preparation for stance stability

Question 16

What does AFOs provide during stance phase?

Answer 16

-optimize position of ankle/foot
-influence proximal alignment
-provide external support for stance stability
-depending on the device, may also facilitate forward progression

Question 17

What are 5 types of AFOs?

Answer 17

-Solid (fixed) AFO
-Hinged (articulating) AFO
-Anterior floor reaction
-Energy storage and return
-Tone inhibiting AFO

Question 18

What impact on gait/function does solid/fixed AFO have?

Answer 18

-provides stance stability, medial-lateral support
-accelerated heel rocker
-loss of ankle and forefoot rocker
-assists with foot clearance
-positions foot for IC
-places foot in plantigrade
-places subtalar joint and ankle in neutral

Question 19

What impact on gait/function does hinged/articulating AFO have?

Answer 19

-allows for limited ankle ROM
-provide medial-lateral stability
-can have DF/PF assist/stop
-aides in foot clearance
-some rockers preserved

Question 20

What impact on gait/function does posterior leaf spring have?

Answer 20

-control PF from IC to LR
-allows DF during stance
-support foot during swing phase

Question 21

What impact on gait/function does anterior floor reaction AFO have?

Answer 21

-maintains ankle in proper alignment
-compensates for weak or absent gastroc/soleus muscle
-facilitates Plantarflexion-knee extension couple
-anterior shell controls forward tibial progression

Question 22

Anterior floor reaction AFO are not appropriate for?

Answer 22

-individuals with knee ligamentous instability or genu recurvatum

Question 23

What impact on gait/function does energy storage and return AFO have?

Answer 23

-assist limb clearnace in swing
-positions heel for IC
-assists with forward propulsion

Question 24

Energy storage and return AFO are not appropriate for?

Answer 24

-individuals with moderate to severe hypertonicity

Question 25

What does tone inhibiting AFO used for?

Answer 25

-controls ankle posiiton
-provides stance stability
-inhibits reflexes induced by tactile stimulation
-controls muscles length (spasticity caused by stretch)
-indicated for patients with hypertonicity with significanty impaired motor control

Question 26

How to document OBJECTIVE gait deviations?

Answer 26

-Magnitude (increased, decreased, excessive, inadequatte, lack of timing, related to ROM)
-Side: left/right
-Joint
-Direction/motion: flexion/extension
-phase of gait

Question 27

How to document ASSESSMENT gait deviations?

Answer 27

-include etiology of gait deviation: impaired motor control, abnormal joint ROM, impaired sensation, pain
-impact/significance on functional tasks: weight acceptance, single limb support, swing limb advancement