Lec. 2: Orthoses of ankle and foot Flashcards
WHY ARE ANKLE ORTHOSES COMMONLY USED?
Commonly used for ankle sprains
Mechanism of injury – excessive plantar flexion, supination and
adduction
The purpose of the orthosis is to prevent these motions from
occurring
WHAT ARE THE NEGATIVE
PROLONGED EFFECTS OF AN ANKLE
SPRAIN?
40% with ankle sprains are functionally unstable Lose the ability for the foot to be a rigid lever
An external support may allow normal mechanics while restricting undesired motion
GOALS GUIDING THE ACUTE PHASE OF TREATMENT
- Control inflammation & edema (PRICE)
- Limit inversion and eversion
- Promote dorsiflexion
- Control forces to stimulate collagen alignment
- Stimulate normal proprioceptive feedback
What do all stirrup orthoses try to control
All attempt to control the calcaneus
With stirrup orthoses, what is the purpose of the foot plate
Foot plates can control PF
WHAT IS NEEDED FOR FUNCTIONAL GAIT?
Support of the body weight during stance phase
Foot clearance during swing phase
Foot must be pre-positioned right before heel strike
Reasonable control of foot, ankle, knee and hip
1st rocker of stance
heel rocker
@ initial contact
Controlled by dorsiflexors
2nd rocker of stance
- as the tibia advances from 10 degrees of PF to 10 degrees DF
- Soleus controls eccentrically to control speed
3rd rocker of stance
forefoot rocker
-heel off, and the body weight rolls off the 1st ray for toe-off
Indications for an AFO
-Weakness of the foot, ankle or knee
– Especially to control for:
Toe/Foot dragging
Knee buckling
Compensatory gait deviation
- Prevent and or correct flexible deformity
- Accommodate weight transference with non-flexible/fixed deformity
Contraindications for an AFO
- Open wound in contact with orthosis
- Pathology, impairment or symptom that cannot be improved with an orthosis
Precautions for an AFO
Spasticity
-can cause inc. pressure, causing skin breakdown
Ankle control: What does free motion mean
mediolateral stability and free DF/PF
Ankle control: What does limited motion mean
Motion restricted in one or more plane (DF/PF)
Ankle control: What does solid ankle refer to
No movement allowed
-indicated for severe pain or instability
What is 3 point pressure control
Achieve joint stability by providing points of pressure
- opposing point at or near the axis of rotation
- above the axis
- below the axis
SMO describe a pt’s
Inv/Ev
PF/DF
Knee
Pt has no Inv/ev control
But has PF/DF
And knee control
Fixed AFO describe a pt’s
Inv/Ev
PF/DF
Knee
Pt has no Inv/ev control
Or PF/DF
And decreased knee control
Hinged AFO describe a pt’s
Inv/Ev
PF/DF
Knee
Pt doesn’t have Inv/Ev
Has DF/PF
Dec. knee control
DF-assist AFO describe a pt’s
Inv/Ev
PF/DF
Knee
Has Inv/Ev
No DF/PF (needs assist into DF)
Has knee control
Ground Reaction AFO describe a pt’s
Inv/Ev
PF/DF
Knee
Pt has no Inv/Ev
No DF/PF
Poor knee control
How does a Ground Reaction AFO help control the knee
It has an anterior shell to stop anterior translation of the tibia
How could you test out if a pt would benefit from a DF-Assist AFO
By doing a DF assist wrap
PLS and spiral are examples of
DF assist AFOs
A pt who has fluctuations in edema may benefit from which type of AFO
conventional “metal bar” orthosis.
- it accommodates for this
- has minimal contact with skin
How can an AFO limit genu recurvatum
setting at 5-7 degrees of DF can limit genu recurvatum but pt must have quad strength!
A Ground reaction AFO is indicated for
Excessive KF in WBing
Excessive ankle DF in WBing
What would a Ground reaction AFO with a posterior leaf do?
the posterior capsule would help decrease hyperextension and it will still limit the anterior translation of the tibia
An ankle locked in PF yields what at the knee
Extension
The intrepid dynamic exoskeletal orthosis is better at walking or running
running
What do external to shoe AFOs offer
Only offer DF
