Orthoses Flashcards
What is the correct placement of foot/ankle for neutral position casting?
STJ neutral, MTJ pronated, ankle dorsiflexed
How can orthoses be classified?
based on MOA, manufacturer, or material
what is the most accurate method of classifying orthoses?
MOA
which method is inaccurate, unreliable, and inappropriate way to classify orthoses?
classifying based on materials
when classifying orthoses based on MOA, what are the 2 subcategories?
- functional (aka root, neutral)
- accommodative
Which type of orthoses does not attempt to control motion of STJ and MTJ?
accommodative
which type of orthoses maintans normal foot function at STJ and MTJ?
functional
Which type of orthotic greatly improves functioning of joints proximal and distal to the STJ and MTJ?
functional
which type of orthotic provides comfort from plantar lesions and bony prominences rather than attempt to affect joints proximal and distal to STJ and MTJ?
accommodative
Which type of orthotic alters function of the foot?
functional
which is the thinnest rigid material?
graphite
what is the single most important step of orthosis fabrication?
casting of the foot
what is a negative cast?
the mold of the foot made from plaster or taken in foam material
what is the positive cast?
made from plaster material poured into the negative cast or from laser scan
what are the 3 most common casting techniques?
neutral
partial weight bearing
computerized
casting a functional orthotic uses what kind of casting technique?
neutral casting technique
casting an accommodative orthotic uses what kind of casting technique?
partial weight-bearing casting technique
What type of modifications are made to the positive mold?
intrinsic modification
What types of modifications are made to the orthotic itself?
extrinsic modification
a rearfoot post is an example of what type of modification?
extrinsic modification
What does CAD/CAM scan?
scans negative cast or the foot driectly
Where does a functional orthotic design end?
ends behind metatarsal heads and just lateral to 1st met and just medial to 5th met (not full width)
where does an accommodative orthoses end?
is full length and full width
which material is closed cell?
spenco
which material is open cell?
poron or PPT
What is “open cell”?
ex. poron or PPT
an open cell material has open windows leaving many cells interconntected so that gas can pass from one cell to another
what is “closed cell”?
made of discrete cells thru which gases do not pass freely
what happens as the # of open cells decrease (becomes more “closed”)?
the ability of the material to withstand compression increases –> is more durable
What is the mechanical objective of a functional orthotic?
- resists GRF that cause abnormal motion to occur during STANCE PHASE
- makes foot stable at push off
- controls hypermobility of joints
what are the uses of an accommodative orthotic?
- relieve high pressure areas
- accommodate plantar lesions
- reduces shock, limits shear forces
an accommodative orthotic is used in what type of feet?
neuropathic
vascularly impaired
arthritic
feet with inoeprable bony or soft tissue prominence
