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