lumbopelvic part 1 Flashcards
describe the vertebral body
large, transverse diameter greater than A-P and height
progressively wedge shaped L1-L5 (L5 greatest) - anterior body larger than posterior
describe the spinous processes
broad, thick from lateral view, thin superior view
large muscular attachments
attachment of thoracolumbar fascia
describe the transverse processes
large for muscular and ligamentous attachments
at same level of own spinous process
describe the facets
lie in sagittal plane
superior facets are concave and face medially and slightly posteriorly
inferior facets are convex and face laterally and slightly anterior
are the facets a weight bearing structure?
technically yes because they are not 100% in the sagittal plane but not much
what are some passive stabilizers to the lumbopelvic region?
ALL
PLL
interspinous, supraspinous and ligamentum flavum
iliolumbar ligaments
thoracolumbar fascia
describe the anterior longitudinal ligament
very strong and broad
anterior to AOR
describe the posterior longitudinal ligament
narrows to non existence in the lumbar spine
some don’t even have a PLL at this level
posterior to AOR
describe the iliolumbar ligaments
5 bands extending from L4 and L5 TPs to iliac crests just above the PSIS
as a whole are very strong and prevent anterior displacement of L4 and L5
posterior to AOR
describe the thoracolumbar fascia
3 layers, ant/middle/post
attached to SP and TP and other tissues and muscles
what are the anterior and middle layers of the throacolumbar fascia derivatives of?
the quadratus lumborum and attaches to TPs
what does the posterior layer of the thoracolumbar fascia fuse with?
the transverse abdominis, gluteus maximus and latisimus dorsi then attaches to the SPs
what do the vertical fibers of the thoracolumbar fascia attach to?
gluteus maximus and SP
what do the horizontal fibers of the thoracolumbar fascia attach to?
the transverse abdominus and abdominal obliques to SP
what do the oblique fibers of the thoracolumbar fascia attach to?
the latissimus dorsi and SP
active muscles create tension of the fascia which transmit what?
longitudinal tension to the tips of lumbar SPs for passive stability
describe what happens with co-contraction during lifting in regards to the thoracolumbar fascia?
it gets pulled in all directions which means the spine stays in neutral and is safe
what muscles make up the erector spinae group?
iliocostalis, longisimus, and spinalis
describe the erector spinae muscles as a group
common origin on iliac crest and sacrum and insert laterally
diverse= origin to insertion is relatively central to lateral
very long cross many motion segments as well as having multiple attachments
what kind of muscle is the erector spinae group? (spurt or shunt)
spurt they are a mover muscle
what movements does the erector spinae muscles do?
extension, lateral bending, and rotation to ipsilateral side
describe the multifidi and rotatores
short muscles, TP to SP
converge= origin to insertion is relatively lateral to central
what kind of muscle are the multifidi and rotatores (shunt or spurt)?
shunt muscle because they are stabilizers and cross 1 or 2 segments however have low angle of pull secondary to converging
what movements do the multifidi and rotatores do?
create SB to same side and rotation to opposite side acting unilaterally, extend.
what is the action of the rectus abdominus?
to create trunk forward flexion (top-down motion) or posterior pelvic rotation (bottom-up motion)
what are the agonists and antagonists to standing trunk flexion?
agonist: con RA to initiate flex then gravity
antagonist: ecc errector spinae
what are the agonists and antagonists to standing trunk extension?
agonist: initial burst of erector spinae then gravity
antagonist: ecc RA
is lying on your back going to do a crunch a top down or bottom up motion?
top down
is a reverse crunch (bringing your knees to chest) a top down or bottom up motion?
bottom up
how do the external obliques run?
start superolateral and run inferomedial “hands in front pockets” - ribs 5-12 to anterior iliac crest and pubic tubercle
what is the action of the external obliques?
rotate trunk to contralateral side
how do the internal obliques run?
“hands in back pockets” - inguinal lig, anterior crest to inferior ribs 10-12 and linea alba
what is the action of the internal obliques?
rotate trunk to ipsilateral side
do both the internal and external obliques attach to thoracolumbar fascia?
external obliques are questionable but internal definitely do
describe co-contraction at the trunk
contraction of trunk flexors and extensors simultaneously = core stability
compressive forces inc shear forces dec
what 3 things increase with co contraction?
intrathecal pressure
intra-abdominal pressure
intradiskal pressure
when the erector spinae contract they shorten and thicken which pushes the TFL to do what?
increase its passive stabilization component
what is the mechanism of force transmission through an IV disc?
compression force via superincumbent BW and muscle contraction raise hydrostatic pressure in disc
increased pressure increases tension in annulus fibrosis
this increased annular tension inhibits radial expansion on nucleus-rise in nuclear pressure is exerted on endplates proximal and distal (hoop stress)
increased nuclear pressure reinforces the peripheral annulus fibrosis converting it into a stable WB structure
the pressure is ultimately transmitted across the endplates to the next vertebrae
what is the orientation of the lamellar ring of the annulus fibrosis?
arranged in multiple concentric layers
every other layer running in the same direction
approx 65-80º from vertical
entire disc itself is a check rein to rotation
describe the osteokinematics of the lumbar kinematics
facet orientation dictates flexion/extension is primary direction of motion
flexion more limited than extension- flexion requires synergistic activity of pelvis
where does the greatest flexion occur?
at L4/5 and lumbrosacral junction
does SB and rotation increase or decrease from L1-L5?
decrease
what are the arthrokinematics for flexion?
superior and anterior slide (more anterior than superior)
what are the arthrokinematics for extension?
posterior and inferior
