Thoracolumbar Spine/SIJ Osteology and Arthrology Flashcards
What are the 3 divisions of vertebrae:
vertebral body
posterior elements
pedicles
Function/role of vertebral body:
anterior, primary weight-bearing component
What makes up the posterior elements of the vertebrae:
transverse/spinous process, laminae, articular process
Function/role of pedicles:
the bridge that connects body posterior elements; thick and strong, transfers mm. forces applied to posterior elements for dispersion across body/disc
What is the purpose of spinal curves:
provides strength and resilience (spring-like) but is vulnerable to shear forces at transitions
What is the function/role of spinal ligamentous:
limits motions help maintain natural curves, protect the spinal cord/nerve roots by stabilizing the spine
Ligamentum Flavum location and function:
ant. lamina to pos. lamina
end ROM flexion 80% elastin, pos. to spinal cord
Interspinous ligament location and function:
between the adjacent SPs; blends with LF
more elastin; more superficial, more collagen, and blend w/SS lig, directions varies-L/S
Superspinous Ligament location and function:
between tips of SPs
resists separation -flexion, less developed in L/S
Intertranverse Ligamnet location and function:
thin taut in contralateral SB
Between TPS
Ant. longitudinal ligament (ALL) location and function:
long, strong strap-like, occiput to the sacrum,
fibers into and reinforce ant. disc
Pos. longitudinal ligament (PLL) location and function:
posterior surfaces of vertebral bodies, C2-sacrum (in canal),
blends w/ and reinforces posterior discs
Capsular ligaments (facets): location and function:
the entire rim of facets, connects and stabilize
reinforced by adjacent muscles (multifidus)
What is the neutral zone?
the amount of intervertebral movement that occurs with the least passive resistance from the surrounding tissues (minimal stiffness zone)
If the neutral zone grows larger as disc degeneration or ligamentous injury occurs what happens:
there is more laxity or instability in the spine to control and more demands are placed on the stabilizing systems
T or F: the larger the neutral zone the more slide, glide, and rotation between vertebrae.
True
This system is thought to send feedback to the neural subsystem about joint positions and challenges at the passive level
-what structures are involved?
passive system
-bony structures, ligaments, joint capsules discs and passive portion of musculotendinous units
_______ system is composed of the muscles and tendons and is the subject of the core exercises
active system
__________ system receives and transmits information from and to the other two systems to manage spinal stability
neural system
What is the SPs alignment in relation to the vertebral bodies in the t-spine?
SPs are pointing downward
What is the orientation of the articular facts in the t-spine?
-sup/inf. oriented vertically
-sup facing posterior/inf.
-anterior; aligned close to the frontal plane
What is the orientation of the articular facets in the L/S
articular facets oriented vertically
–sup; concave, face medial to med-pos.
–inf; articular facet convex, lateral to ant. lateral
What are the arthokinematics of flexion in the t-spine and lumbar spine?
facets slide sup. and slightly ant.
flexion - limited by connective tissues located posterior to the vertebral bodies
What are the arthokinematics of extension in the t-spine and L-spine?
facets slide inf. and slightly post.
15-20º of extension limited by tension in ALL and lamina of adjacent vertebrae
Why is there more flexion/extension in the lower T/S in relation to the upper T/S:
free floating ribs and facets more sagittal
What are the arthokinematics of lateral flexion (SB) in the thoracic and lumbar spine?
-what structure prohibits greater SB?
contralateral facets slide sup. ant. and ipsilateral facets slide inf. pos.
-ribs
What are the arthokinematics of rotation in the thoracic and lumbar spine?
contralateral facets slide sup. ant. and ipsilateral facets slide inf. pos.
Ant. pelvic tilt with lumbar extensions leads to excessive ________ and tight _______ muscles
-migration fo NP?
-nutation or counternutation of the sacrum?
lordosis; hip flexors and back extensors
-NP migrates ant.
-in extension of the vertebral column sacrum moves forward: nutation
The annulus fibrous has _______ concentric rings of ________ fibers.
-Prevents?
-Entraps?
-Outer layer contain?
15-25; collagen
-prevents distraction/shear/torsion
-entraps encase liquid-based nucleus
-outer layer contains disc-only sensory nerves, binds to ALL, PLL ( outer more collagen inner more water)
How does the AF get nutrition?
through normal compressive forces that produce evenly distributed loads. - GAGs
Can the vertebral endplate calcify/crack? If so what happens?
Yes, which can lead to reduced permeability and PGs
-less water
-less ability to absorb and transfer loads
-not just with aging but with excessive/abnormal loads
IVD as a hydrostatic pressure distributor:
Where is most of the load during standing?
Compressive loads push endplate ______ to _______
80% carried on the intervertebral joint at L/S
20% posterior elements
inward;NP
What is viscoelasticity?
resists a fast/strongly applied load;
less resistance to slow or light compression
**(flexible low loads/rigid higher loads)
What is the migration of the disc in flx/ext?
flx- posterior mirgration
ext- ant. migration
What is the difference between diurnal fluctuations: morning and evening?
morning: supine low pressure- attract water, swell slightly when sleeping
—1% height change–
evening: PGs reduces-water retaining reduces, less hydrostatic pressure
The function of the thoracic spine during inspiration/expiration:
inspiration=extension
expiration=flexion
What is contracting/tight in post. pelvic tilt:
abdominals and hip extensors
What are the structures resisting shear at L5-S1
disc, capsule of facets, ALL
-iliolumbar ligament and QL is a firm anchor between L5 and ilium/sacrum
What is centralization and peripheralization?
centralization: full lumbar ext. reduces pressure and reduces contact pressure between discs and neural tissues; abolination of distal to promixal P!
-perpherialziation opposite
What are the three phases of lumbopelvic rhythm:
-what happens if the hamstrings are tight?
- lumbar flexion
- lumbar flexion (45º) + hip flexion (60º)
- hip flexion
Limited hip flexion and thoracic and/or lumbar spine have to compensate.
