Flashcards in Sacrum I Deck (30)
What is the composition and function of the sacrum?
Composition: 5 separate segments that were fused early in life
Function: protects reproductive organs
Which ligaments stabilize the sacrum by limiting motion?
- Ventral/Anterior sacro iliac
- Dorsal/Posterior sacroiliac
True or False: The sacrum and L4 have an intimate relationship
False: The sacrum and L5 have an intimate relationship
The base of the sacrum projects forward and articulates with a lumbar vertebrae to form the...
What muscles are associated with the sacrum?
Superior and Inferior gemelis
A tight piriformis is responsible for what symptom?
An iliacus in spasm can cause what to happen to the sacrum?
rotation of the sacrum.
L5 rotations also rotate ...?
Describe the sacrum in relation to the pelvis.
The sacrum is suspended between the ilia by three true and three false ligaments. The sacroiliac joints are L-shaped joints that allow gliding in rotation on the order of millimeters.
True or False: Movement of the sacrum is produced only by ligaments, not by muscles.
The most cephalad part of the sacrum is called the ...?
The most caudad part of the sacrum is called the...?
The superior poles are ..... and .... to the PSIS.
medial and superior to the PSIS's
Just cephalad to the ILA's on the sacrum bone are the......?
Lateral and cephalad to the coccyx are the....
inferior lateral angles (ILAs)
The superior transverse axis is at what level? What is the Superior transverse axis involved in?
the superior transverse axis is involved in respiratory flexion and extension synchronous with sphenobasilar (Cranial flexion and extension).
The middle transverse axis is at what level? What does the middle transverse axis allow for?
The middle transverse axis allows for postural flexion and extension that is coupled with but opposite the direction of lumbar flexion and extension
What does the inferior transverse axis allow for?
rotation of the ilia on the sacrum during walking = iliosacral motion.
During inspiration, what direction does the base and apex of the sacrum move?
base moves posterior
apex moves anterior
During exhalation, what direction does the base and apex of the sacrum move?
base moves anterior
apex moves posterior
True or False: Motion occurs along an axis, not around the axis.
False; Motion does not occur along an axis, it occurs AROUND an axis.
Which axis is responsible for rotation of the sacrum?
Which axis, which is perpendicular to the plane of the sacrum, has side bending occur laterally around the axis?
What axis runs from the upper part of the sacroiliac articulation to the lower part on the opposite side and occurs naturally when shifting weight from one foot to another?
When diagnosing a sacral dysfunction via static testing, what are you looking for?
sacral suclus depths and position of inferior lateral angles (cephalad vs. caudad and anterior vs. posterior)
When diagnosing a sacral dysfunction motion testing, what tests can you perform?
- Seated flexion test
- lumbar spring test
- backward bending (Sphinx) test
- Respiratory movements of sacrum
- Passive motion testing of sacrum
What does the seated flexion test tell you? When will you have a false negative?
The seated flexion test identifies the SI joint that is stuck.
Since it finds dysfunctions that are unilaterally dominant, you will have false negative in dysfunctions that affect both SI joints.
What does the lumbar spring test tell you?
A positive (hard end feel/resistance) in a dysfunction in which all or part of the base is stuck posterior.
What does the backward bending (sphinx) test tell you?
Because backward bending should move the base anteriorly, findings are described as more symmetrical or less symmetrical (more asymmectrical).
Dysfunctions resulting in a part of the sacral base getting stuck posteriorly become more asymmetrical.
Dysfunctions resulting in a part of the base getting stuck anteriorly become more symmetrical