Anatomy and Biomechanics of L Spine Flashcards
what composes the anterior column of the spine?
vertebral bodies
intervertebral discs
function of anterior column of the spine
hydraulic and WB
shock-absorption
what composes the posterior column of the spine?
articular processes
facet joints
purpose of posterior column of spine
gliding mechanisms for movement
what joints compose each spinal segment?
anterior: 2 vertebral bodies + IVD
posterior: 2 facet joints
which articular orientation facilitates axial rotation? blocks?
facilitates - horizontal
block - vertical
how are L spine facets oriented?
sagittal
what does the AMOUNT of available spine motion depend on?
disc-vertebral height ratio
compliance of fibrocartilage
dimensions & shape of adjacent end plates
age
disease
gender
what does the TYPE of available spine motion depend on?
shape & orientation of articulations
ligaments & muscles of segment
size and location of segment’s articulating processes
what is the largest avascular structure in the body?
intervertebral discs
C & L IVDs are thicker in the _____ portion
anterior
which segment’s IVDs are uniform?
T
which 5 stresses does IVDs resist?
axial compression
shearing
bending
twisting
combined motion
T/F: IVDs resists tension forces
F
what are the 2 types of stability of the spine?
mechanical - static
controlled - dynamic
what 3 components make up controlled (dynamic) stability of spine?
passive
active
CNS
which forces does the passive stability of the spine resist?
translation
compression
torsion
local ___ and global ____ = function
local mobility and global stability = function
what is the capsular pattern of the L spine?
SB = rotation then extension
which is larger in the L spine: spinous or transverse process
transverse
what is lumbarization?
S1 more mobile than normal
what is sacralization?
L5 fuses to sacrum
how are the facets of the upper L spine oriented? lower?
upper - sagittal
lower - coronal
T/F: the articular cartilage of the synovial joints of the L spine are avascular and aneural
T
normal intact disc: facet joints carry ____% of axial load
20-25%
when a disc is degenerated the facet joints carry ___% of axial load
70%