Thoracic & Lumbar Spinal Mechanics Flashcards
What are the 4 junctions of the body?
Craniocervical, cervicothoracic, thoracolumbar, and lumbosacral
What landmarks of the body does the line of gravity pass through?
External auditory canal, head of humerus, L3, anterior third of sacrum and lateral malleolus
Describe the body of thoracic vertebra (T1-12)
Medium sized, heart shaped and costal facets are present
Describe the spinous process of thoracic vertebra
Long and slope posteroinferiorly
Describe the body of lumbar vertebra (L1-5)
Large and kidney shaped
Describe the spinous process of lumbar vertebra
Short and broad
What does the rule of 3’s refer to?
The location of the spinous process in relation to the transverse processes in the thoracic spine
T1-3 spinous process are located at the level of the
Corresponding transverse process (rule of 3’s)
T4-6 spinous processes are located
1/2 a segment below the corresponding transverse processes (rule of 3’s)
T7-9 spinous processes are located at the
Level of the transverse process of the vertebrae one below (rule of 3’s)
Same rule applies for T10
Ex. T7 spinous process is at the level of T8 transverse processes below T7
T11 transverse process follow the same rule as
T4-6
T12 transverse processes follow the same rule as
T1-3
Spinal landmark for the spine of the scapula
T3 spinous and transverse process
Spinal landmark at the inferior angle of the scapula
Spinal process of T7 and transverse process of T8
Spinal landmark at the iliac crest
Level of L4 vertebra
What is the orientation of the superior facets on cervical vertebra?
Backward, upward, medial (BUM)
What is the orientation of the superior facets on thoracic vertebra?
Backward, upward, lateral (BUL)
What is the orientation for the superior facets on lumbar vertebra?
Backward and medial (BM)
What is the acronym for superior facet orientation?
BUM BUL B(M)
Cervical thoracic lumbar
Rotatores bilateral action
Extends thoracic spine
Rotatores unilateral action
Rotates thoracic spine to opposite side
Multifidus bilateral action
Extends spine
Multifidus unilateral action
Flexes spine to same side and rotates it to opposite side
Semispinalis bilateral action
Extends thoracic and cervical spines and head (stabilizes craniovertebral joints)
Semispinalis unilateral action
Bends head, cervical and thoracic spines to same side & rotates to opposite side
Describe vertebral nomenclature
Motion is always referenced to the movement of the anterior/superior surface of the vertebra Excessive motion (or restriction) is in reference to the superior vertebra in a functional vertebral unit (ex. Excess motion of L2 is the motion of L2 on L3)
Why does spinal somatic dysfunction matter?
Restrictions of motion in the spine reduce efficiency, impair flow of fluids, alter nerve function and create structural imbalance
What are the two models that explain how somatic dysfunction can occur?
Muscle tightness/dysfunction model and the facet model
Explain the muscle tightness/dysfunction model
Rotatores muscles affect a single segment (sidebend and rotate in the same direction)
Semispinalis and multifidus affect multiple segments (sidebend and rotate in opposite direction)
Explain the facet model
In the neutral range (not flexed or extended) the facets are not engaged
In flexion the facets are open
In extension the facets close
According to the facet model, if a facet is dysfunctionally open and wont close then the vertebra is
Flexed
According to the facet model, if a facet is dysfunctionally closed and wont open, the vertebra is
Extended
An example of a facet that is stuck open (facet model)
If a vertebra’s right facet is open but will not close & the left side has normal motion, when extension is induced the vertebra will sidebend and rotate to the left
Stuck open = sidebend and rotate away (from the side that wont close)
An example of a facet that is stuck closed (facet model)
If a vertebra’s right facet is closed but will not open and the left side has normal motion, when flexion is induced the vertebra will sidebend and rotate to the right
Stuck closed = sidebend and rotate toward (the side that wont close)
Who is Harrison Fryette, DO?
He described physiological motion of the spine taking into account normal and abnormal (somatic dysfunction)
Published in 1918 (bolded in lecture)
Developed two principles of spinal motion that are applicable to the thoracic and lumbar spine
C.R. Nelson, DO developed the third principle in 1948 (also bolded)
Describe type one spinal mechanics according to the Freyette principles
In the neutral range (not flexed or extended) sidebending and rotation are coupled in opposite directions
Rotation is toward the convexity of the spine
Tends to be a group of vertebra (greater than 2) and although uncommon it can happen in a single vertebra
The facet model would not apply in the neutral range
Muscle dysfunction model: semispinalis and multifidus affect multiple segments (sidebend and rotate in opposite directions)
Freyette type one mechanics memory tools
Type One Neutral Group Opposite “N” for neutral - arrows point in opposite directions (side being and rotation are opposite)
Type one mechanics nomenclature
- Locate the vertebra or group (ex. T1-3)
- Indicate position (N - neutral)
- Indicate sidebending (SR sidebent right and restricted to left sidebending)
- Indicate rotation (RL rotated left and restricted to right rotation)
Ex. T1-3NSrRl
Describe type two mechanics according to Fryette’s principles
In sufficient flexion or extension (non-neutral) sidebending and rotation are coupled in the same direction
Rotation is towards the concavity of the spine
Tends to be a single vertebra and although uncommon it can be in 2 adjacent segments
Muscle dysfunction model: rotatores muscle affect a single segment (sidebend and rotate in the same direction)
Facet model would apply to this principle
Fryette’s type two mechanics memory tools
Type Two 0 non-neutral Single segment Same direction “F” and “E” for flexion and extension - arrows go in the same direction
Fryette’s type two mechanics nomenclature
- Locate the vertebra group (ex. T9)
- Indicate position (F flexion or E extension)
- Indicate sidebending (ex. Sidebent left and restricted to right sidebending)
- Indicate rotation (ex. Rotated left and restricted to right rotation)
Ex. T9 F SL RL
Describe Fryette’s third principle
Initiating a movement of a vertebral segment in any plane of motion will modify the movement to that segment in other planes of motion
According to Fryette’s third principle, if motion is restricted in one direction then
Motion will also be restricted in other directions
According to Fryette’s third principle, if motion is improved in one direction then
Motion will improve in other directions
Which of the three Fryette principles apply to thoracic and lumbar spine ONLY?
Type one and two mechanics
List equivalent terms when describing a vertebra that will not rotate to the left when pushing anterior on the right transverse process
Posterior transverse process (PTP) on the right Right PTP Rotated right Hard end feel with rotation to the left Hard end feel on the right (when applying anterior force to the right transverse process) Restricted in rotation to the left Will not rotate to the left Lives in right rotation Held to the right
