Principles of orthotics Flashcards
How to develop an orthotic perscription
- evaluate examination findings to indentify: impairments, activity/participation restrictions
- develop specific goals for orthosis
- design orthosis that applies forces necessary to achieve orthotic goals
Review of examination findings: limitations of functional activities may be caused by…
- insufficient limb/joint movement
- abnormal limb/joint movement
- excessive limb/joint movement
- limb/joint deformity/alignment
developing goals for orthosis
what are the four general categories
- assist joint movement when joint movement is insufficient (weakness)
- stabilize joint by limiting motion when joint movement is excessive, abnormal, or unwanted
- protect joint from excessive, unwanted or deleterious loading/forces that may cause pain or injury
- assist in management of joint/skeletal deformities
Using biomechanical principles when designing orthosis
force application to produce movement when insufficent joint movement
- designed that store and release energy
- manipulate the GRF vector or LOG to produce movement
- use functional electrical stimulation to substitute for weak muscles
Using biomechanical principles when designing orthosis
for application to limit, control, or stop movement (when joint movement is abnormal or excessive)
- use 3-4 point counterforce systems or force couples
- designed that enhance rigidity across joints or slow movement
- manipluate GRF vector or LOG to stop/restrain unwanted movement
LOG = line of gravity
How to manipulate LOG to influence ankle and knee
- indirect control of knee position
- ankle in DF modifies LOG to create a flexion moment at knee
- ankle in PF modifies LOG to create and extension moment at the knee
Factors to consider when choosing biomechanical methods to achieve orthotic goals
- least control that is effective
- interferes least with normal movement
- minimizes energy cost
- applies force close to impairments
- minimizes negative side effects
- maximizes all function
temporal Appliances
- use less expensive splinting /casting materials, elastic bandages or tape
- may not be safe for use outside of clinical setting
- but can observe and evaluate proposed orthotic solution
Ankle foot orthosis components
- foudation
- ankle control
- foot control
- superstructure
AFO: foundation
what is it and describe the two types
- shoe+insert
- insert - plastic carbon fiber
- portion of orthosis that contacts plantar surface of patients foot
- must be worn with shoe that closes high on dorsum of foot
- stirrup-metal
- riveted to bottom of shoe
- heavier than plastic insert foundations
AFO: ankle control how do most AFOs control ankle
- limiting plantarflexion and/or DF
- assisting motion
Plastic:
- adjust trimlines: narrow = more movement wider= more stability
- energy storing material: provide motion assist
- mechanical block to motion
Ankle control
energy storing material
- fiberglass, carbon fiber and kevlar orthosis
- provides DF assist
- best for foot drop with mild to moderate ankle instability
- contraindicated in those with spasticity, edema
how do these types of orthotics work?
Energy storage and release
- similar to a diving board storing and releasing energy
- dynamic response prosthetic foot and orthosis
Ankle control: mechanical block
- plastic AFO with posterior stop
- limits PF ROM
- produces flexion moment at knee
- prevents knee hyperextension
Ankle control
metal ankle joints
orthotics
- free motion - provides M/L ankle control
- single adjustable can provide PF stop or DF assist or free motion
- double adjustable posterior channel: can provide PF stop or DF assist or free motion
- double adjustable anterior channel can provide DF stop of PF assist or free motion
Foot control
- limits eversion and inversion
- plastic
- solid ankle with trimlines anterior/posterior to malleoli
- hinged AFO metal
- T-strap
Superstructure
- portion of AFO above ankle and foot components
- plastic AFO
- metal-leather AFO
Superstructure
plastic AFO
- usually a single upright or shell can be posterior to anterior
- broad surface to minimze pressure
Superstructure
metal-leather orthosis
- bilateral uprights
- leather-covered calf band
Benefits of AFOs for hemiplegia
- prevent/reduce PF and inversion contractures
- improve balance
- improve gait
how can an AFO improve gait in a hemiplegia patient
- restore heel contact
- absorb shock on paretic limb
- increase midstance stability
- improve forward progression in late stance
- enable paretic limb to clear floor during sing
- increase velocity
- decreased energy cost of walking
Benefits of AFOs with CP
- improved stride length
- improved gait velocity
- increased DF during swing phase
- most: best with hinged ankle joint - less energy expenditure
- those with marked knee flexion -better with floor reaction orthosis
orthosis for M/L control
UCBL
- university of california biomechanics laboratory
- corrects hidfoot valgus, limits subtalar motion
- trimlines inferior to malleoli
- high force over small areas often difficulty to tolerate
Orthosis for M-L control
SMO
- Supramalleolar orthosis
- stabilizes calcaneus, limits subtalar motion
- limits midfoot pronation/supination
- trimlines extend above malleoli
LE orthotic terminology
- FO
- SMO
- AFO
- KAFO
- HKAFO
- KO
- HO
- FO: foot orthosis
- SMO: supra-malleolar orthosis
- AFO: ankle foot orthosis
- KAFO: knee ankle foot orthosis
- HKAFO: hip knee ankle foot orthosis
- KO: knee orthosis
- HO: hip orthosis
UE orthosis
- FO
- HO
- WHO
- WHFO
- EWHO
- SEWHO
- EO
- SO
- FO: finger orthosis
- HO: Hand orthosis
- WHO: wrist hand orthosis
- WHFO: wrist hand finger orthosis
- EWHO: elbow wrist hand orthosis
- SEWHO: shoulder elbo wrist hand orthosis
- EO: elbow orthosis
- SO: shoulder orthosis
spinal orthotics terminology
- SO
- LO
- LSO
- TLSO
- CTLSO
- CTO
- CO
- CRO
- SO: sacral orthosis
- LO: lumbar orthosis
- LSO: lumbar sacral orthosis
- TLSO: thoracic lumbar sacral orthosis
- CTLSO: cervical thoracic lumbar sacral orthosis
- CTO: cervical thoracic orthosis
- CO: cervical orthosis
- CRO: cranial remolding orthosis
orthotic terminology
off the shelf (OTS)
- sized item
- no modifications or custizations made to device
Orthotic terminology
custom fit
- sized item
- requires modifications or customizations for proper fit and support
orthotic terminology
custom made
- custom made for individual based of cast, scan or measurements
Orthotic terminology
goals of orthotics
- support or stabilize
- prevent or correct deformity
- decrease or increase ROM
- pain control
- healing
Orthotic terminology
soft orthotic
- cushioning, protection, off- loading
- often for diabetics
Orthotic terminology
semirigid orthotics
- firm but flexible base
- increased control and stability
Orthotic terminology
rigid orthotic
- rigid plastic or carbon base, strong control and correction
