SI Joint Flashcards
Functions of SI joint
transfer load from trunk to legs (standing, walking)
absorbs LE motions/forces
The lumbopelvic region consists of?
Lumbosacral junction
SI joints
Pubic symphysis
Hip joints
Coccyx
What makes up the osseous ring?
Ilium
Sacrum
Pubis
Which lumbar segments make up the lumbosacral junction?
L4,5 and S1
What is the orientation of L5 and S1 facets?
Frontal
What are the L5 and S1 facets made up of?
Dense cartilage
For weight bearing
How is the iliolumbar ligament attached?
From L4/5 transverse process to iliac crest
Connected to QL muscle
What is the function of the iliolumbar ligament?
Restricts all planes of movement
Which ligament can be the source of unilateral pain in lumbosacral junction?
Iliolumbar ligament
Osteokinematics: Sacroiliac during LUMBAR motion - Nutation
Nutation (flex) = Anterior and Inferior
Osteokinematics: Sacroiliac during LUMBAR motion - Counternutation
Counternutation (ext) = Posterior and Superior
Osteokinematics: Sacroiliac during LUMBAR motion - Axial Rotation
Reciprocal motion of unilateral
Nutation and Counternutation
Osteokinematics: Iliosacral during HIP motion - anterior rotation
ASIS Inferior, PSIS Superior
Osteokinematics: Iliosacral during HIP motion - posterior rotation
ASIS Superior, PSIS Inferior
Biomechanics: Trunk Flexion
Both innominate anteriorly rotate
Sacrum nutates and then counternutates
Biomechanics: Trunk Extension
Both innominate posteriorly rotate
Sacrum nutate
Biomechanics: Hip Flexion
Unilateral innominate posterior rotation
Sacrum nutates
Biomechanics: Hip Extension
Unilateral innominate anterior rotation
Sacrum counternutates
What ligament limits anterior gapping
Anterior (Ventral) sacroiliac ligament
What ligament limits posterior gapping?
Interosseous ligament
What ligament limits sacral counternutation (backward tilting)?
Posterior (long dorsal) sacroiliac ligament
What ligament limits sacral nutation (forward tilting)?
Sacrotuberous ligament
What ligament limits sacral nutation?
Sacrospinous ligament
Attachments of Posterior (long dorsal) sacroiliac ligament?
PSIS to S3-4
Connects Thoracolumbar fascia and Erector Spinae
Attachment of Sacrotuberous ligament?
PIIS to S3-4 to Ischial tuberosity
Connects to bicep femoris
List the inner tube pelvic girdle muscles
TA
Multifidus
Diaphragm
Pelvic Floor
List the outer tube pelvic girdle muscles and systems
Longitudinal (Erector spinae, TLF, bicep femoris, sacrotuberous lig)
Oblique (Anterior - Int/Ext Oblique, Abdom fascia, ADDuctors) (Posterior - lats, TLF, glut max)
Lateral (Glut med, min, ADDuctors)
Ventral Rami innervates what segments?
L5-S2, branches from sacral plexus
Dorsal rami innervates what segments?
L5, S1-4
