L2: AFOs Flashcards
When we refer to “Traditional” orthotic
Whats that mean
Metal bars and leather
Old School!!!!!
Orthotics always go one joint above what you want to control
******
Rockers:
3
- Heel
- Ankle
- Toe (Forefoot)
Rockers:
Heel
- IC→Foot flat
- DEceleration of foot→floor
- Wt Acceptance
Rockers:
Ankle
- MSt as tibia advances over fixed foot
- Triceps surae eccentrically controls speed of tibia (decelerates)
Rockers:
Toe (Forefoot)
- Tst→ Push-off
- BW rolls over MTP jts
AFO Terminology
NOTE: trimlines, straps, footplates
AFOs
Goals and Gait Prereqs:
-
Goal:
- Safe, energy efficient gait
-
Gait Prereqs:
- Stability in stance
- Swing phase prepositioning
- Clearance in swing
- Adequate (symmetrical) step length
- Energy conservation
Note about step length involved vs uninvolved
Involved LE will CAUSE shorter step length on contralateral side (good side)
AFOs
Stability in Stance
- AFO controls instability by optimally aligning ankle
- application and loc of forces in M/L or A/P directions
- Ideal for pes equinus or ankle vaRus deforms
AFOs
Stability in Stance
Fulcrum vs Counter Forces
- Fulcrum→ Anterior ankle
- Counter forces→ Plantar surf foot and posterior proximal calf
AFO
Clearance in Swing
- Keeps foot neutral==incd qual of swing due to:
- Dec DF strength
- poor timing
- abnorm EXT synergy
AFO
Swing Phase Repositioning
- Maintains ankle in neutral DF and ev/inv to prep for wt acceptance
AFO
Adequate Step Length
- Maints stability of talocrurcal joint in TSt and PSw→ allows CONTRALAT. LIMB to maint. proper step length
- effective propulsion of limb in Sw when needed
AFO
Energy Conservation
*CRITICAL in neuro pop.
- Critical neuro pop→ return to IND community amb.
- Controls ankle and knee jts during St and Sw===Less energy cost
- *Less compensatory mechs==Less energy !!!
PF + DF associations
Excess PF== Knee EXT (PE class**)
Excess DF== Knee FLEX (buckling)
AFO
*rigid solid ankle AFO that fixes ankle in DF prevents
Knee HyperEXT
AFO-Force Systems
What all AFO’s do inherently
- Notice where Fc is and what is being controlled!!!
- Fp= proximal force
- Fd= distal force
AFO force system
PF control
NOTE: Fprimary
AFO controlling excessive PROnation
notice Medial flange
MOST AFOs are ________
Custom Molded (MAFOs)
MAFOs
Custom Molded
- Intimate fit, light, distributes forces effectively, fits most shoes, modified for relief,
- Does NOT accommodate for fluctuating edema ***
AFO Types: 2
Classified by function
-
Static Ankle Foot Orthosis
- MAX control
-
Dynamic Ankle Foot Orthosis
- Incs DOF→ someone w/ better control
Static AFO’s
4:
- Solid Ankle
- Anterior Floor Reaction
- set in PF→ knee hyperEXT bias
- Patella Tendon Bearing
- Supramalleolar (SMO)
- high top→ PEDS
Dynamic AFOs (DAFO)
4:
- Posterior Leaf Spring (PLS) (Thermoplastic)
- Conventional DF assist
- Articulating thermoplastic
- Hybrid (metal-plastic)
AFOs ex’s
see pics
Static AFO’s (max control)
Primary function
- maint. ankle/foot in a fixed pos. @ TCJ, STJ, forefoot
-
Effectively:
- assist w/ Sw clearance
- preposition foot for IC
- EXT stability for knee & ankle t/o stance
Static AFO
Solid (non-articulated) ankle AFO
Drawbacks and what to do about it
- Drawback→ all rockers compromised
-
AFO fabrication→ Shoe mods:
- Inc cushion heel→ compensates for heel rocker
- Rocker bottom (entire sole)→ comps for 2nd/3rd rockers=== smooth forward translation t/o Stance
Solid Ankle AFO:
Indications
- Those who need total immob. of ankle/foot complex
-
Controls:
- Inv/Ev
- foot drop (but not all need MAFO)
- Ext tone/synergies→ Mod Ashworth know it!!
- Knee hyperFLEX (biases to PF)/knee hyperEXT (biases to DF) → you know WHY!!
Solid Ankle AFO
Thermoplastic piece
- Thermoplastic piece encompasses most of lower leg
- Trimlines→ anterior to malleoli
Solid Ankle AFO
To control for abnorm toe grasp (CP, spastic CVAs):
LONGER toe/footplate
Tone inhibiting bar
Static AFOs w/ articulation have ability to max. control:
4 things:
- Ankle DF/PF
- Inv/Ev
- Knee hyperEXT
- Knee buckling (hyperFLEX)
Static AFOs w/ articulation have ability to max. control:
Ankle DF/PF
HOW?
- A/P force coupling→ 3pt system
- Length of foot plate
- Thickness of foot plate
Static AFO’s w/ articulation have ability to max. control:
Inv/Ev
HOW?
- Med→Lat force coupling
- Ankle/foot trimlines**