Orthotics Flashcards
Don’t forget…
to review the different ways to tie shoes!
Mechanisms behind patients with patello-femoral pain syndrome being helped by orthotics
- reduction in obligatory IR of the LE
- reduction in dynamic Q-angle
- reduction in laterally-directed soft tissue forces acting on knee
- reduction in patellofemoral contact pressures as a result of improved contact with femur
Indiciations for foot orthotics
- plantar fasciitis
- ITBS
- hallux rigidus
- midfoot OA
- balance issues
Tissue stress theory
- Kirby
- orthotics attempt to minimize excessive stress/symptoms
Foot morphology theory (root) and sagittal plane facilitation theory (dananberg)
Kostka says “do not focus on these too much)
- foot morphology theory - focuses on subtalar joint neutral position (rearfoot and forefoot in neutral alignment)
- Sagittal place facilitation theory - ankle equinus and functional hallux limitus
First 3 principles of orthotic management
- “normal” alignment of structures distal to proximal
- Allow adaptation to ground surfaces without compromise of anatomical structures because of either hypermobility or hypomobility
- Protect compromised soft tissue structures from excessive stress (e.g. plantar fascia, posterior tibialis)
“Normal” alignment of structures distal to proximal
- metatarsals heads contracting ground (directly or indirectly)
- relative neutral forefoot to midfoot orientation
- relative neutral rearfoot to leg orientation
Principles 4-6 of Orthotic Management
- provide a stable BOS
- provide a rigid lever mechanism for forward propulsion
- do not compromise force absorption mechanisms
Foot orthotic options
- off-the-shelf orthotics
- in-house orthotic systems (quick fabrication or time consuming fabrication)
- orthotic labratories
Examples of off the shelf orthotics
- power step
- superfeet
- dr. scholl
- sof sole
Quick in-house orthotic systems
- resin activated by luke-warm water
- molded in “subtalar neutral”
- extrinsic posting (rearfoot or forefoot post)
Time consuming in-house orthotics
- blank molded with foot in “subtalar neutral”
- cork grinded to provide hindfoot and/or forefoot posting (i.e. medial or lateral)
Orthotic labratories
- based on mold (either plaster cast or foam impression)
- limited adjustablity
- turn around time typically 1-2 weeks
Casting techniques
- plaster cast (gold standard, functional orthotics)
- impression foam (polystyrene)
Plaster cast technique
- NWB (subtalar neutral) with patient in prone position
- may also plantarflex 1st ray during molding in presence of significant forefoot varus and/or hallux rigidus
Impression foam pros/cons
- quicker and cleaner than plaster casting
- best for accomodative molds (bony prominence, callus, fibrous tissue mass)
Full weightbearing impression
- foot in its compensated position
- captures static standing foot deformities
- best for accomodative orthotics (someone who has just had sx or a diabetic)
Semi-weightbearing impression
- with patient seated, clinician applies downward force at teh knee and metatarsal heads
- may distort flexible foot deformities
Non-weight bearing impression
- requires practice
- minimizes distortion of intrinsic foot deformities
General guidelines
- cast or mold in neutral position
- medial rearfoot posting for excessive calcaneal eversion
- medial forefoot posting for excessive forefoot varus
- 1st ray cut out for plantarflexed 1st ray
- lateral hindfoot/forefoot posting for medial knee Oa/forefoot valgus
Full length vs. 4/3 length
- full length allows for more control, but is difficult to fit in every shoe
- 3/4 length is less control, but fits into more shoes
Rigid orthotic
- control
- excessive pronator
- not always tolerated
Semi-rigid orthotic
- combines control and shock absorption
- active persons/athletes
Soft orthotic
- accommodative problems (diabetic)
- attempts to increase contact area in efforts to reduce pressure
General guidelines for posting
- used to further modify the positive cast (intrinsic) or the orthotic (extrinsic)
- intrinsic post - modifications made to the shape of the positive impression
- extrinsic post - providing an external “build-up” to the orthotic
Rearfoot posting
- commonly used for abnormal hindfoot pronation
- medial instrinsic or extrinsic post
Forefoot posting
- used to correct either varus or valgus deformities through a medial or lateral wedge respectively
- varus: medial
- valgus: lateral
Heel cups/pads
- for plantar fasciitis
- increases contact areas
- extra padding to help absorb forces
Metatarsal pads
- morton’s neuroma
- attempt to splay apart metatarsals
Heel lifts
- achilles tendonitis
- ankle equinus
- limb length inequality
- 3/8”: limit inside shoe
Distal leg varum causes the hindfoot to…
evert in order to bring the medial aspect of the foot to the ground
Review rearfoot leg angle graph
-comparing subtalar joint neutral, relaxed stance, and SLS on orthotic prescription lab handout
Longitudinal arch angle
- staggered stance with equal weightbearing
- good indicator of arch angel during walking and running
- pronated (150 degrees)
- see picture
Forefoot to rearfoot alignment
- good reliability with visual estimation
- poor reliability with use of goni
1st ray position and mobility
- position: plantarflexed (below the other 4), neutral, DF
- mobility: rigid (doesn’t even reach the level of the other 4), normal (anything in between), hypermobile (goes beyond the other 4)
- poor reliability for both measures
REview the foot posture index?
maybe?
