orthotic goals
correction, accommodation, stabilize, reduce pain
correction goal
- for flexible deformity
- restore follower load
- reduce moment
how do we measure correction? success?
measure by doing a Cobb angle
accommodation goal
- for fixed deformity
- want to prevent deformity from progressing
stabilization goal
- limit gross vertebral sway
- decrease moment
- increase load carrying capacity
- ex: fractures
reduce pain goal condition examples
spondylylosis and spondylothesis
free desired control
motion is free
- ex: elastic binder
stop desired control
posterior component that stops ext
hold desired control
limiting motion throughout entire plane
- ex: burst fracture
hold-variable desired control
mainly used for transverse plane; allows best chance at managing rotary deformities
list of biomechanical principles of spinal orthoses
- end-point control
- total contact
- three point pressure system
- kinesthetic reminder
- increased intracavitary pressure
what is end-point control
motion control of a free body
what theory is associated with end-point control
Euler’s theory
critical load definition
upper limit of a load that the spine can withstand before it bends
end-point control application
scoliosis to increase stability
end-point control explanation for curve progression during height/weight changes
10% increase in height or weight changes leads to an automatic 20% decrease in the critical load or spinal stability
total contact purpose
applying forces to get correction
- pressure = force/area
what is the three-point pressure system
2 forces going in the same direction and the 3rd force going in an equal and opposite direction
what is the purpose of a three-point pressure system
- trying to limit motion
- encourage person to withdraw from the stimulus
- introducing a higher shear to moment ratio
three-point pressure system application
used with someone who has a compression fracture
alternative to three-point pressure system
- introduces a more bending moment and taking away the shear
- more comfortable for patient
- designed into an extended position
alternative to three-point pressure application
good for kyphosis
kinesthetic reminder purpose
- reminder to move in a manner slower than normal
- creates a stimulus to withdraw
increased intra-cavitary pressure purpose
- trying to achieve a reduction in discal pressure
