Sacrum Flashcards
What is the composition and function of the sacrum?
Composition: 5 separate segments that were fused early in lifeFunction: protects reproductive organs
Which ligaments stabilize the sacrum by limiting motion?
- Sacrospinous- Sacrotuberous- 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…
Lumbosacral angle.
What muscles are associated with the sacrum?
Piriformis, Iliacus, Obturator internus, Quadratus femoris, Superior and Inferior gemelis, Iliopsoas, Erector spinae
A tight piriformis is responsible for what symptom?
Sciatica
An iliacus in spasm can cause what to happen to the sacrum?
rotation of the sacrum.
L5 rotations also rotate …?
the sacrum
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.
True
The most cephalad part of the sacrum is called the …?
base.
The most caudad part of the sacrum is called the…?
apex
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……?
inferior poles.
Lateral and cephalad to the coccyx are the….
inferior lateral angles (ILAs)