Week 5 - Thoracic Spine and Ribs

Question 1

Which region of the spine is considered the least mobile region?

Answer 1

The thoracic spine, majority of flexibility actually comes from lumbar and cervical spine.

Question 2

How many thoracic vertebrae are there?

Answer 2

12

Question 3

How many thoracic apophyseal (facet) joints are there?

Answer 3

24 (12 on each side)

Question 4

What is unique about the thoracic vertebrae?

Answer 4

Vertebral body and transverse process have costal articulating surfaces.

Question 5

How many ribs do the thoracic vertebrae articulate with?

Answer 5

12 pairs

Question 6

Which thoracic vertebrae are considered transitional?

Answer 6

T1, T11, and T12

Question 7

Why is T1 considered a transitional joint? (4)

Answer 7

1. characteristics and bony design similar to cervical spine
2. full articular facet for the head of the 1st rib and demi-facet for the upper half of the 2nd rib
3. Body transverse diameter is 2x size of A-P diameter
4. Spinous process is long and primnent

Question 8

What is the typical vertebral body of a throacic vertebrae? (2)

Answer 8

1. V. body is equal in the transverse and A-P diameter

2. V. bodies are wedged shaped (posterior height is greater than anterior height) (generally peaks around T7)

Question 9

What does the wedge shape of a thoracic vertebral body lead to?

Answer 9

wedge shape = kyphotic posture of ~40-45 degrees that is typically seen in thoracic spine

Question 10

As you move from the cervical to lumbar region, how do thoracic vertebrae change?

Answer 10

1. Width increases caudally (v. body wider and larger)
2. Spinous processes angle inferiorly
3. Transverse processes angle posteriolaterally
4. Disc height ratio to the V. body size is smallest in the spine (said to contribute to greater stability rather than mobility)

Question 11

What is the thorax made up of? (3)

Answer 11

thoracic spine, ribs and sternum

Question 12

What does the thorax provide? (3)

Answer 12

in total this provides a stable base, protects vital organs, provides mechanical billows for ventilatory functions

(said to contribute to greater stability rather than mobility)

Question 13

What kind of joints are the throacic apophyseal joints

Answer 13

Plane synovial joints that are relatively flat (consist to all facet joints in spine)

Question 14

What is the orientation of the thoracic apophyseal joints?

Answer 14

Lie ~20 degrees off Frontal plane and 60 degrees from the Horizontal plane

Question 15

What does the orientation of the the thoracic apophyseal joints allow and not allow for in terms of movement?

Answer 15

allowing for greater motion to occur in lateral flexion and rotation, not as much into flexion and extension

Question 16

Where are flexion and extension especially limited in the thoracic spine?

Answer 16

upper regions of throacic spine

Question 17

What is unique about the lower region thoracic spine apophyseal joints and movement? (2)

Answer 17

1. apophyseal joints lie closer to sagittal plane and therefore allow more flexion and extension to occur
2. lower ribs have fewer attachments to the thoracic spine and this too may contribute to more flexion and extension.

Question 18

What direction do the superior facets face?

Answer 18

Face posteriorly, slightly superiolaterally

Question 19

What direction do the inferior facets face?

Answer 19

Face anteriorly, slightly inferiomedially

Question 20

How does the orientation of the apophyseal joints change as you move down the lumbar spine?

Answer 20

More to sagittal plane changing mobility

Question 21

What degree of flexion is available at the Thoracic spine?

Answer 21

30 - 40 degrees

Question 22

What are the arthrokinmatics of flexion at the thoracic vertebrae?

Answer 22

Inferior facet of the superior vertebrae slides superior/anterior on the superior facet of the inferior vertebrae below (similar to mid and lower cervical spine)

Question 23

What limits flexion of the thoracic vertebrae?

Answer 23

limited by tension in connective tissues posterior aspect of thoracic region

Question 24

What degree of extension is available at the Thoracic spine?

Answer 24

20-25 degrees

Question 25

What are the arthrokinmatics of extension at the thoracic vertebrae?

Answer 25

Inferior facet of the superior vertebrae slides posterior/inferior on the superior facet of the inferior vertebrae below (similar to mid and lower cervical spine)

Question 26

What limits extension of the thoracic vertebrae?

Answer 26

limited by tension anterior connective tissues and posterior bony structures

Question 27

What plane does rotation occur in at the thoracic region?

Answer 27

Transverse Plane

Question 28

What degree of rotation is available at the thoracic spine?

Answer 28

30-35 degrees of motion available to each side

Question 29

What are the arthrokinematics of rotation available at the thoracic spine?

Answer 29

Inferior articular facet of superior vertebrae slides against superior facet of inferior vertebrae below in the direction of rotation.

Question 30

What degree of lateral flexion is available at the thoracic spine?

Answer 30

25 - 30 degrees of motion available to each side

Question 31

What plane does lateral flexion occur in the thoracic region?

Answer 31

Frontal Plane

Question 32

Even though the facets of the thoracic region like 20 degrees from the frontal plane, why is lateral flexion limited?

Answer 32

The ribs contribute to this limitation

Question 33

What are the arthrokinematics of lateral flexion available at the thoracic spine?

Answer 33

Inferior facet of the superior vertebrae on the ipsilateral side slides inferiorly on the superior facet of the inferior vertebrae.

Inferior facet of the superior vertebrae on the contralateral side slides superiorly on the superior facet of the inferior vertebrae.

Question 34

What happens to the ribs during lateral flexion?

Answer 34

The ribs drop down on the side of lateral flexion and move slightly upward on the contralateral side.

Question 35

Describe couples motion in the thoracic spine.

Answer 35

too variable and highly controversial. more research is required.