E2 Flashcards
(134 cards)
Axis is located anteriorly at the level of S2, near the junction of the long and short arms of the SI joint
Middle transverse
Axis on which the sacrum flexes and extends in response to truncal motion
Middle transverse
What is the normal motion of the middle transverse axis?
Slight truncal F/E –> sacrum flexes and extends with the spine
Further flexion (lumbar lordosis begins to reverse) –> sacrum extends
Further extension –> sacrum flexes
Who demonstrated the mobility of the sacrum on the middle transverse axis radiographically?
Kottke in 1962
Who demonstrated the mobility of the sacrum on the superior transverse axis radiographically?
Pruzzo in 1971
This axis is located in the posterior superior sacroiliac ligaments, about the level of S2
Superior transverse
Axis the sacrum moves upon with ventilation
Superior transverse
What is the normal movement of the superior transverse axis?
Inhalation –> extension
Exhalation –> flexion
Cranial base flexion –> extension
Cranial base extension –> flexion
Axis upon which motion of the sacrum occurs, synchronous with cranial movement during the cranial rhythmic impulse cycle
Superior transverse
Axis at the level of the ILAs
Inferior transverse
Axis on which the inominates rotate during the gait cycle
Inferior transverse
What are the oblique axes named for?
Their superior pole
This is actually an axis of pelvic rotation during the gait cycle, but it appears to be located posteriorly in the vicinity of the sacrum
Vertical
Sphinx test –> sacral sulci become more symmetric
Anterior dysfunction
What is a torsion?
Two parts of an object rotating in opposite directions about a single axis
What is the normal torsional mechanism of L5?
L5 is tightly anchored to the iliac crests by iliolumbar ligaments, so L5 moves with the ilia. When you compare L5 to the position of the sacral base, it appears that the two have rotated in opposite directions about a vertical axis.
What is a compensated L5?
Normal torsional mechanism of L5
What is a non-compensated L5?
When L5 rotates with the sacrum rather than the ilia
What determines the direction of sacral rotation?
Motion of the anterior most point on the sacral promontory
What causes an anterior sacral torsion?
- Truncal sidebending and rotational forces in extension coming down from the lumbar spine
- Exaggeration of the gait cycle
What are the symptoms of anterior sacral torsion?
Backache, buttock ache
What causes a posterior sacral torsion?
Truncal sidebending and rotational forces in flexion coming down from the lumbar spine
(NOT caused by gait cycle)
What are the symptoms of a posterior sacral torsion?
Intense low back and hip pain, piriformis pain, patient often walks with a limp
Extra deep sacral sulci
Increased lumbar lordosis
Bilaterally flexed sacrum