Thoracic Spine and Movement
What limits Spinal Lateral Flexion
- Annulus - Inter-transverse ligaments - Posterior trunk muscles on convexity of curve
What occurs during Thoracic Spinal flexion
- Anterior tilting and gliding of superior vertebrae - Separation of spinous processes - Widening of intervertebral foramen
What limits Spinal extension
- Bony contact between spinous process - A.L.L. - Anterior annulus - Facet joint capsules - Anterior trunk muscles
What are the different movements of the thoracic spine with their degrees
- Extension: 20-25 - Lateral Flexion: 25-30 - Rotation: 30-35 - Flexion: 30-40
What occurs during Thoracic Lateral flexion
- Lateral tilting and gliding of superior vertebrae (if initiated cranially) - Annulus Fibrosis is compressed on concavity of curve - Narrowing of intervertebral foramen on concavity
What limits Spinal flexion
- Posterior ligaments (supra and inter-spinous, PLL, ligamenum flavum) - Posterior annulus - Facet joint capsules - Posterior muscles (spinal extensors)
What occurs during Thoracic Spinal extension
- Posterior tilting and gliding of superior vertebrae - Approximation of spinous processes - Narrowing of intervertebral foramen
What are characteristics of the thoracic vertebrae
- Triangular shaped vertebral body - Inferiorly sloping spinous processes - Transverse processes have facets for articulation of ribs - Bodies have demi-facets for articulation of ribs
How much Thoracic Spinal Extension do we have
20-25 degrees
How much Lateral flexion do we have
25-30 degrees
How much Thoracic Spinal Rotation do we have
30-35 degrees
How much Thoracic Spinal flexion do we have
30-40 degrees
What is a Schmorl's Node
A herniation of the nucleus into adjacent endplate
Why are problems rare in the thoracic spine
Because movement is more restricted than the cervical and lumbar spine
Why does rotation decrease in the lower thoracic spine
Because the facets are orienting more toward sagittal plane
According to Maigne, 70% of common thoracic pain is of what origin
Cervical origin
How do Schmorl's Node occur
Excessive loading which causes fractures of the endplates with subsequent herniation
Where do discogenic problems in the thoracic spine radiate to
It radiates to the sternum
How are the Lower segments of the thoracic facets inclined
They are inclined as in the lumbar spin (sagittal plane)
How are the Upper segments of the thoracic facets inclined
They are inclined at 45-60 degrees to horizontal (similar to C spine)
How are the Middle segments of the thoracic facets inclined
They are inclined at 90 degrees to horizontal
