IV. Biomechanics Of The Thoracic Spine And Rib Cage Flashcards
Function of Ribs?
Stabilizers to the spine Decrease the general mobility of thoracic Protect thoracic viscera Function in respiration
Quiet Respiration is mostly:
Diaphragmatic
Forced Respiration is
External intercostals become very active to elevate ribs, as well as activationg of many other secondary muscles
What are some common clinical pain syndromes or traumatic injuries associated with the thoracic spine and ribs?
scoliosis postural myofascial pain syndrome kyphosis compression fractures
Describe the vertebral body in the thoracics
AP and transverse diameters are equal wedge shaped vertically with from 1-2 mm shorter
TPs in the thoracic region point in which direction?
lateral and posterior
TPs are stronger in the lumbar or thoracic region?
thoracic
Describe the SPs in the thoracics
long vertically, less in the upper and lower thoracics common site of spinal anomaly
For T1-T4, where are the TPs in relation to the SPs?
up 1 interspinous space and lateral
For T5-T7, where are the TPs in relation to the SPs?
up 2 interspinous space and lateral
For T8-12, where are the TPs in relation to the SPs?
up 1 interspinous space and lateral
What is the average IVD height in the thoracics?
5mm
What is the ratio of IVD to disc in the thoracics?
1:5
What is the ratio of IVD to disc in the cervicals?
2:5
What is the ratio of IVD to disc in the lumbars?
1:3
Articular facets in the thoracics form what angle with the horizontal plane and vertical plane?
60º with horizontal
30º with vertical
In the thoracics, what is the general orientation of the articular facets and how do they change superiorly and to inferiorly?
Overall they are in the coronal plane but they become more sagittal inferiorly
In the cervical region, what plane are the articular facets in?
Oblique and transition to coronal inferiorly
In the lumbar region, what plane are the articular facets in?
Sagittal and transition to coronal inferiorly
Is there any concavity/convexity to the articular facet surfaces in the thoracics and if so what?
No, they are flat unlike the cervical and lumbars
What direction do the superior articular facets face in the lumbars?
posterolateral, superior
What direction do the inferior articular facets face in the lumbars?
anteriomedial, inferior
How do ribs articulate to the vertebral bodies?
Costovertebral joint: via demi facets on vertebral body above and below
Describe the articulation of a constotransverse joint
the rib articulates the the TP of the corresponding vertebrae
Which ribs terminate anteriorly with costal cartilage?
1-10
Which ribs are free floating (no costal cartilage)?
11-12
Which ribs attahc via their costal cartilage to the seternum through true synovial joints?
1-7
Which ribs attach to the sternum via common costal cartilage?
8-10
What is the range the thoracic kyphosis?
25-45º
What is happening to the articulation?
distraction
What is happening to the articulation?
approximation
Which rib is the stiffest?
2
Which rib is the most flexible?
10
The stiffness of the rib cage is how many times more than that of any single rib?
10-20
Resection of the costovertebral joints lead to what?
instability of the involved motion segment
Stiffness of the thoracic spine is ________ times greater with the rib cage?
2.5
The thoracic spine is ______ times more resistant to compression with the rib cage
4
Tensile properties of the thoracic spine are increased ____ % with the rib cage
40
What is the global range of motion for flexion of the thoracic spine?
50º