Intro To Sacrum Flashcards
anterior sacral landmarks
base ala superior articular process anterior sacral foramen coccyx sacral promontory pelvic brim transverse line apex
posterior sacral landmarks
superior articular facet canal articular surface posterior sacral foramen coccyx haitus inferior lateral angle median, intermediate, lateral crest spinous tubercles
the lowest part of the spinal column, four vertebra, some fused, some not
coccyx
the sacrum is formed by the union of _____ modified vertebrae
five modified vertebrae
epiphyseal plates separate adjacent sacral segments and fuse sequentially after puberty from _____ to _____
inferiorly to superiorly
the bony vertebral arch fuses with its adjacent ______ _____ between years 2 and 5
costal elements
bony articulations of the sacrum include
1) ____
2) ____
3) _____
- fifth lumbar vertebrae
- coccyx inferiorly
- two os coxae (innominates) through the c shaped SI articulations
SI joint development after puberty in males and females
males: SIJ joints are well developed and strong
females: SIJ joints are less well developed allowing the mobility for childbirth
during the second decade of life, describe the development of the SI joint
crescent shaped ridge devleops along the iliac surface that interdigitates with a depresion on the sacral side
adds stabiity and mobility
describe the development of the SI joint during the third decade of life
crescent shaped ridge becomes more pronounced decreasing ROM more
Males: degenerative changes may begin to occur on the iliac side
describe the dev of the SI joint during the fourth and fifth decades of life
males: degenerative changes begin on the sacral side
fibrous ankylosis may further limit joint motion
Characteristics of the SI joint
L or C shaped shorter upper arm longer lower arm S2 level ]Apex points anteriorly diarthroidal joint (1 side hyaline 1 side fibrocartilage) Sacral side : smooth, hyaline Iliac - smooth, fibrocartilage
which ligament connects the 3rd sacral segbment to the lateral side of the pre-auricular sulcus
Anterior SI ligament
which ligament is formed from fibers of the 3rd and 4th sacral elements and ascends to the PSIS and posterior end of the internal lip of the iliac crest
posterior SI ligament
what ligament blends with STL and the thoracolumbar fascia
posterior SI ligament
what ligament connects the PSIS to the lateral aspect of the 3rd and 4th sacral segments and maintains a close anatomical relationship with the erector spinae muscle group, posterior layer of the thoracolumbar fascia and sacrotuberous ligament
the long dorsal SI ligament
this ligament may be stretched when the sacrum is rotated in a posterior manner relative to the ilium (counternutation) in
pregnancy
aging and degenerative changes
backward torsion or unilateral/bilateral sacral extensions
long dorsal SI ligament
ligament from ischial spine to lateral margins of sa crum where it blends with the sacrotuberous ligament
sacrospinous ligament
ligament that runs from lower sacral tubercles to ischial tuberosity
serves as an attachment site for gluteus maximus
tendon of biceps femoris
connects with fascia of the pelvis
sacrotuberous ligament
together, these two ligaments stabilize to limit posteiror-superior rotation of the sacral apex around a transverse axis
Sacrospinous
sacrotuberous
action of the piriformis
external rotation of the hip
pathology that can result from piriformis hypertonicity
sciatica
sciatic nerve runs in close proximity (and sometimes through) the piriformis m
posterior pelvic landmarks
PSIS
ASIS
ILA
differiential static landmarks for determining if sacral base is more anteiror or posterior
sacral sulcus
