Thoracic Spine/Rib Cage Biomechanics Flashcards
What are the three distinct regions of the thoracic spine that have specific variations?
upper thoracic = T1-T4
middle = T5-T9
lower = T10-T12
Body characteristics of thoracic spine
wedged-shaped (kyphotic curvature on sagittal plane)
increase in size from superior to inferior
inferior endplates are larger
In which direction are the thoracic body vertebrae larger?
larger AP diameter than ML (bodies)
characteristics of facets for heads of ribs
complete facets = T1 and T10-12
demifacets for the remaining
- ribs 2-9 connect in bettween vertebrae and act as a wedge to limit motion – limit motion btwn vertebral bodies
demifacets
head of rib articulates at the level of the vertebral disc and connects to the above and below body with two facets
Articular processes of thoracic spine
pedicle to lamina junction (superior and inferior)
orientation affects segmental motion
more vertically aligned to 75 degrees at T6-T7
limit flexion
minimal axial rotation allowed due to how steep the facets are
lateral flexion is limited
lower thoracic limited in axial rotation
Articular processes of thoracic spine for what?
form zygapophyseal joints
in which direction do the superior facets face?
posterior and lateral – lower thoracic direction changes to medial orientation, which explains the difference in mobility in different aspects of the thoracic spine
articular processes of thoracic spine – motions allowed
limit flexion
minimal axial rotation allowed due to how steep the facets are
lateral flexion is limited
lower thoracic limited in axial rotation
T/F few limitations to axial rotation in the thoracic spine, but limitations in flexion.
true
palpating thoracic spine
space indicates IVD level (palpation)
Muscle attachment processess
TP and SP
transverse length decreases from T1-T12
- anterior aspect is facet for rib tubercle
spinous process muscle attachment processess
upper is more horizontally aligned
middle is post and inferior
lower is shorter and projects posteriorly
tip of process in line with body of inferior vertebrae (t2-T12)
TP’s increase in size down vertebrae. this impacts LF
ribs of thoracic cage
12 pairs and sternum
head and neck face posterior towards spine
body is anterior = costal cartilage and sternum
typical ribs
2-9
head of rib
superior/inferior facets - demifacets
neck
extends posterior and lateral from head
tubercle of rib
located on posterior surface
single head facet rib numbers
1st, 10-12th
rib facets
T2-T9 = head of rib has 2 facets
T1, 10, 11, 12 = one facet
neck extends psot lat and meets TP
sternum
convex anterior concave posterior flat manubrium, body, ziphoid process sternal notch at T3 body at T5-T9 sternomanubrial junction = 160 degrees xiphisternal junction ossified by age 40
sternal notch
T3
body of sternum
T5-T9
Joints of thoracic region (5)
- interbody joints
- zygapophyseal
- costovertebral
- costotransverse
- rib to sternum