intro to sacrum Flashcards
lumbarization of sacrum
when S1 and S2 do not fuse
anterior surface of the sacrum is ___ posterior surface is __
concave, convex
the lateral rows/crests of sacrum are what and end as what
fusion of sacral TP and end as ILA
where is the sacral epidural nerve block performed
sacral hiatus
sacral canal contains what
cauda equina
what is the ganglion impar
where the right and left sympathetic chains join, rests on anterior aspect of coccyx
true pelvic ligaments
sacroiliac ligaments, attach bone to bone
anteior SI ligament attachments
3rd sacral segment to preauricular surface of ilium
interosseous sacroiliac ligament attachments
medial sacral crestes to iliac tuberosities
posterior SI ligament attachment
PSIS to 3rd and 4th sacral segments
sacrotuberous ligament has what attach here
gluteus maximus and tendon of biceps femoris
sacrotuberous and sacrospinous action
stabilize anterior, prevent posterior superior rotation
iliolumbar ligament attachment and function
attaches 4th and 5th lumbar verterba to iliac crests
stabilizes posterior motion, restricitng anterior motion of L4/L5
primary intrinsic muscles of pelvic diaphragm
levator ani group: iliococcyg, puborect, pubococcyg, coccyg
secondary muslces considered to have partial attachment to true pelvis
rectus ab, internal oblique, external oblique, transversus abdominus, quad lumborum
what spinal muslces also have direct connection to sacrum
eretor spinae and multifidus
force closure
hold an object by pressure on sides —>I
form closure
stacking or use of roman arch as self supporting structure
superior transverse sacral axes
respiratory axis
nutation and counternutation from SBS flexion/extension
articular processes of S2
middle transverse sacral axis
postural axis for flexion/extension in sitting and standing
level of body of S2
inferior S3 axis
iliosacral, axis for rotation of the iliums on sacrum
axis when moving and walking
