Axial Skeleton Flashcards
Vertebrae function
Vertical stability
Protects spinal cord/nerve roots
Normal curves of cervica/lumbar spine
Convex anteriorly
Normal curves of thoracic/sacral spine
Convex posteriorly
LoG falls to _______ side of each curve at apex
Concave side
Ligamentum flavum action
Resists flexion
Supraspinous and interspinous ligament function
Limit flexion
Intertransverse ligament function
Resist contralateral flexion
Ligamentum Nuchae function
Thickening of supraspinous ligaments in cervical area
Adds support to head
ALL function
Limits overall extension
Limits excessive lordosis in cervical/lumbar regions
PLL functioni
Reinforces intervertebral disks
Limits excessive flexion
Capsular ligaments of spine
Surround each apophyseal joint
Sustains 1000 N
Limits all motion except extension
Typical cervical vertebrae
C3-C6
Atypical cervical vertebrae
C1C2
AA Joint motion
Rotation
“Typical” thoracic vertebrae
T2-T9
Describe thoracic vertebrae
Pedicles directed posteriorly
SPs slant downward
TPs sland posterior-laterally
Describe lumbar vertebrae
SPs- broad, rectangular, project horizontally
TPs- project laterally
Articular Facets- Oriented nearly vertical (Superior posterior-medial, Inferior anterior-lateral)
Function of sacrum
Transmits weight of vertebral column to pelvis
SP/TP function
Increase mechanical leverage of muscles/ligaments
Apophyseal joints AKA
Facet joints
Facet joint function
Guide intervertebral motion
Interbody joint function
Connect intervertebral disc with pair of vertebral bodies
Horizontal facets of apophyseal joints…
Factor axial rotation
Vertebral facet function
Block anterior translation and axial rotation
What is annulus fibrosis
Concentric layers of collagen fibers encasing the nucleus
Function of intervertebral discs
Protect interbody joints: absorbs/distributes loads
Protect apophyseal joints: minimize compressive loads
Provide stability at spine
Positions/activities of lowest interdiscal pressure
Laying supine = lowest
Also low; laying on side, sitting with incline (110?)
Positions/actions of highest interdiscal pressure
Highest = bending over with legs straight to lift object
Other high pressure: lifting with bent knees, holding object, bending over to reach object
Two DoF of AO joint? Main action?
1-Flexion/extension
2- Lateral flexion
Main = flexion extension
2 DoF of AA joint
1- Rotation
2- flex/ext
Main = rotation
DoF of C2-C7
3 DoF due to 45 degree facet angle
Arthrokinematics of neck extension
Posterior slide
Arthrokinematics of neck flexion
Anterior slide
What has more range–protraction or retraction?
Protraction
Protraction :
Flexes ________
Extends ________
Flexes mid/lower Cspine
Extends upper CSpine
Retraction:
Extends _____
Flexes ______
Extends mid/lower Cspine
Flexes upper Cspine
Arthrokinematics of cervical rotation
Slide posterior on ipsilateral slide, anterior on contralateral
Arthrokinematics of lateral flexion
Roll ipsilateral, slide contralateral
Coupling in CSpine
Ipsilateral– Right sidebending = Right rotation
TSpine: limited movement secondary to ____
Ribs
TSpine:
Flexion
Extension
Total Motion
Flex 30-40
Ext 20-25
Total Motion: 50-65
Lumbar has more ________ motion than _______
More flexion/extension than rotation (because of facet orientation)
Lumbar ROM
Flexion 40-50
Ext 15-20
Total 55-70
Tspine rotation
30-35
Tspine lateral flexion
25 to 30
Spine rotation
5-7
Spine lateral flexion
20 degrees
Thoracolumbar flexion arthrokinematics
Superior slide
Arthrokinematics of thoracolumbar extension
Inferior slide
Thoracolumbar rotation arthrokinematics
Ipsilateral slide
Thoracolumbar lateral flexion arthrokinematics
Slides inferiorly ipsilaterally, superiorly contralaterally
Used as intervention to reduce spinal nerve root pressure due to narrowing of foramen
Full lumbar flexion (increases foramen diameter)
Lumbar extension _____ contact pressure between articular facets
Increase contact
Forward flexion w/knees straight– how much lumbar flexion and how much hip flexion
40 lumbar 70 hip
They can compensate for each other because of lumbopelvic rhythm
Extension of trunk w/knees extended initiated by
Extension of hips, then extension of spine
This reduces load on L spine and extensor muscles
With a stabile trunk, APT ______ lumbar lordosis
Accentuates – hip flexors, back extensors
With a stabile trunk, PPT _______ lumbar lordosis
Reduces
Hip extensors and abs
SI Joint = articulation between…
R/L auricular surfaces of sacrum and uricular surface of ilium
Is si joint stabile or mobile
Stabile–reinforced by ligaments and muscles
SI joint pain associated with…
Trauma, repetitive strain, posture or unknown origin
**menstrual cycle can greatly impact SIJ laxity
SIJ…
- Ratation
- Translation
1-4 degrees rotation
1-2 mm translation
What is nutation?
Sacral on iliac rotation - posterior pelvic tilt
What is counternutation
Iliac on sacral rotation - anterior pelvic tilt
Purpose of nutation torque
Increases SIJ stability
In nutation, weight of hat translated …
Through L5, anterior to 1st sacral vertebrae
Biggest concern with core stability
Their ability to stabilize– intrinsic stabilizers of the trunk
How to stabilize spine
Controlling alignment and stiffness at intervertebral junctions
Lack of fine intrinsic core muscle control leads to
Vulnerable vertebral column
About extrinsic muscle stabilizers
Don’t stabilize at segmental level–they’re bigger and stronger on most people but we need both external and internal to work together
When does whiplash occur
Craniosacral muscles can’t react
First muscles to turn on in shoulder flexion
Internal abdominals, THEN anterior delt
This does not happen in pts with LBP because they don’t anticipate task
(Your body anticipates the task and so it turns on internal abs to stabilize before moving appendicular skeleton)
