csp spinal mechanics Flashcards
purpose of csp
=to orientate head in space- eyes are level with horizon. Huge amount of movement available (greatest in comparison to other parts of spine)
OA–> flexion and ext
C1,2–> rotation
C3,4–> greatest rom for whole csp
tsp–> least amount of rom
mechanism of forces
-tension
-compression
-bending
-shear
-torsion
-combined loading
lever mechanism
1st class lever (fulcrum around occipital-atlanto condyles)
tubular structure= allows for flexibility and strength (e.g. small vessels & ligamentous tube)
ligamentous tube= individual ligaments creating a sleeve together (scarum to nuchal line). Gives structural integrity and strength
articular pillar
=modification of facets on pedicle
typical features:
body–> small triangular with joints of von luschka
sp’s–> c2-3 bifid, c4-7 long
vertebral foramen–> small
tp–> has transverse foramen or vertebral artery
facet orientation–> coronal 45 degrees
occipito-atlanto joint
RA= inflammatory arthropathy. Over time repeated episodes of inflammation will damage and weaken ligaments. Will become loose and fragile
hypermobility= congenital connective tissue problem. More movement in neck as the ligaments are looser
roll and slide: Concave facet- atlas (slides) and Convex- occiput (rolls). Roll and slide on each other
Fixed around mastoid process
Occiput is active, C1 is passive
extension: occiput rolls posteriorly whilst atlas slides anteriorly
facet orientation
Facets are 45 degrees to transverse plane and lie parallel to frontal plane
OA- roll and slide
Other segmental areas have roll and slide
Side bending- where there is side bending there is a degree of rotation
Rotation- articular pillar starts below c2. Allows for rotation to occur. Must be mindful of vessels
neurological spinal points of vulnerability
Intervertebral foramen- spinal nerves exit (have a fascial sheath around it)
Herniated discs protrude posterior laterally- in contact with spinal nerves
