Three Point Pressure Systems Flashcards
Parallel Force Systems
Two forces of equal magnitude acting in the same direction within the same plane, with a counter force in the middle
Number of forces required to control angular motion?
Three
(One active, two stabilizing)
What side of deformity should the stabilizing forces be located?
Concave
What side of deformity should the active force be located?
Convex side
Factors to manipulate rotation
Distance and Force
What occurs when a system is not balanced at equilibrium?
Rotation (joint motion or pressure)
Direct Force
How Ox Work
Orthosis applies force directly on body segments
UL management heavily reliant on this concept
Indirect Forces
How Ox Work
Orthosis uses and modifies external forces acting on body segments, beyond the physical boundaries of the orthosis
* i.e. gravity, momentum, GRF
primarily used in LL
Area
Design Principles
Increased to reduce pressure
Location of Active Force
Design Principles
Position active force as close to the joint as possible
* This may involve contact proximal and distal to the joint
Avoid applying forces directly on bony areas
Maximum Effectiveness
Design Principles
active force must match as closely as possible the direction of desired motion or control
