Vertebral Mechanics: The Fryette Model Flashcards
Define the 4 segmental motions.
- Rotation - movement in a transverse plane about a vertical axis
- Sidebending - movement in a coronal plane about an anterior-posterior axis
- Flexion - anterior movement in a sagittal plane about a transverse axis
- Extension - posterior movement in a sagittal plane about a transverse axis
What are the 2 types of axial motion?
Rotational (motion ABOUT an axis) & translational (motion ALONG an axis)
What are the 3 types of translated motion?
- Lateral - movement in a transverse or coronal plane along a transverse axis
- Vertical - movement in a sagittal or coronal plane along a vertical axis
- Anterior-posterior translation - movement in a transverse or sagittal plane along an AP axis
What is a helical axis?
An axis which is moving about another axis, even while motion is occurring about it.
Example - moon rotates on an axis while rotating around the Earth, which rotates around the sun, which also rotates around its own axis.
What is a vertebral unit?
2 adjacent vertebrae with their associated IV discs; facet arthrodials; and ligamentous, muscular, vascular, lymphatic, and neural elements.
When referring to motion of a single vertebra, we are actually referring to what?
That segment’s vertebral unit.
Diagnosed somatic dysfunction may be referred to in terms of what?
Its position or directions of motion restriction relative to the vertebra below.
What are the suffixes for positional diagnosis?
-ed/-ent
flexED, rotatED, extendED, sidebENT
What are the suffixes for motion restriction diagnosis?
-ing/-ion
flexION, rotatION, extensION, sidebendING
Which is used more often - positional or motion restriction language - when describing segmental dysfunction?
positional nomenclature
How is somatic dysfunction named (in terms of direction)?
Direction of freedom and ease.
In what year did Fryette do his work and what method did he use?
1918; he used palpation
To what parts of the spine do Fryette Mechanics apply?
Lumbar & thoracic spine only.
What does it mean to say that sidebending and rotation are coupled?
You can’t have one without the other.
What are the 2 types of Fryette Mechanics?
Type I - neutral mechanics
Type II - non-neutral mechanics
What are the physiologic laws of spinal motion?
I - in neutral range, sidebending & rotation are coupled in opposite directions
II - in sufficient flexion or extension, sidebending & rotation are coupled in the same direction
III - initiating motion of a vertebral segment in any plane of motion will modify the movement of that segment in other planes of motion
Who described laws I & II of thoracic & lumbar motion? What year?
Harrison H. Fryette, D.O., 1918
Who described law III of Fryette Mechanics? In what year?
C.R. Nelson, D.O., 1948
Describe the neutral position and name the type of mechanics it is.
Neutral position is a range in which weight is predominantly born on the vertebral bodies and discs; the facets are idling. This is Type I Fryette Mechanics.
Describe the non-neutral position and name the type of mechanics it is.
Non-neutral position is sufficiently flexed or extended beyond the neutral range so that non-neutral coupling occurs. This is Type II Fryette Mechanics.
What are the abbreviations for Fryette Mechanics?
N (neutral), F (flexed), E (extended), R (rotated), S (sidebent), R (right; subscript), L (left; subscript)
How would you write L5 Neutral, Rotated Left, Sidebent Right?
L5NRL(subscript)SR(subscript)
or
L5RL(subscript)SR(subscript)
How would you write L5 Flexed, Rotated Right, Sidebent Right?
L5FRR(subscript)SR(subscript)
or
L5FRSR(subscript)
Give 3 facts about Type I dysfunctions.
They tend to occur in groups, but can occur singly.
They often compensate for Type II dysfunctions.
They constitute typical scoliosis mechanics.
