What passes through the four bilateral foramen?
Passage of ventral and dorsal horns of 1st 4 sacral spinal nerves
What causes a defect of the sacral hiatus?
Defect formed by failure of laminal closure of 5th sacral closure
What is the sacroiliac joint? Describe both arms.
L or C shaped
Short upper arm (convex laterally)
Long lower arm (concave laterally)
Describe the form closure of the pelvis?
The way the pelvis, sacrum, and femurs articulate together
The whole sacrum is held in place with the other bones
Describe the forced closure of the pelvis?
Muscles and other forces compresses the sacrum together to stabilize it
Describe the form and forced closure of the pelvis?
When you put anatomy and forces together, this is a dynamic function
Describe the location of the sacral sulcus?
Distance from PSIS to sacral base (described as deep or shallows)
What are the 3 true ligaments between the innominates?
What are the 3 accessory ligaments?
Sacrotuberous: greater and lesser sciatic foramen
What are the suspensory arrangement between vertebra?
Anterior Longitudal ligament
Anterior and posterior sacrococcygeal ligaments
Describe the piriformis?
tightens to stabilize pelvis, opposite to leg in swing phase
Externally rotates, extends the thigh, abducts thigh with flexed hip
Innervated by S1/S2
Describe the ligaments restraining the anterior movement of the sacral movement?
Describe the ligaments restraining the posterior, lateral, and axial movement of the sacral movement?
Anterior sacroiliac ligament
Posterior sacroiliac ligament
Interosseous sacroiliac ligament
What are the tenets of sacral motion?
Muscles are attached to the sacrum
Sacral motion is not caused by these muscles
No muscles are specific for SI motion
What are the forces from above's effect on the SI joint?
Changes of position or center of gravity within the torso
Sacral motion occurs along axes. What are the 3 transverse axes? What are the two oblique axes
Left oblique axis
Right oblique axis
The inferior transverrse axes lies at the level of:
inferior part of the inferior limb of the SI joint
The superior transverse axes does type of motion?
Flexes and extends with respiration
Nutation (flexion) and counternutation (extension) during craniosacral mechanics
The middle transverse axes does what type of motion?
involved in sacral postural flexion and extension
How is an oblique axes developed? what type of motions?
Motions occuring about a vertical and transverse sacral axis: rotation and sidebending
At what level of the SI joint is the middle transverse axes located?
Anterior convexity of the upper and lower limbs of the SI joint
Posterior rotation of the sacral based around the middle transverse is called
(no craniosacral involved here)
Forward rotation of the sacral base around the middle transverse axis is called:
(no craniosacral involved here)
Forward rotation of the sacral base around the superior transverse axis is called:
Posterior movement of the sacral base around the superior transverse axis is called
As your head extends (craniosacral extension), your sacrum around the superior transverse axis:
As your head flexes, your sacrum at the posterior movement of the sacral base around the superior transverse axis:
Why does your respiratory motion affect sacral motion?
Due to the attachment of the diaphragm to the L1-L2 left and L1-L3 right
With inhalation, lumbar lordosis ______ and sacral base moves _______
posterior: postural extension (sacrum moves back)
*think of pulling the spine up**
With exhalation, lumbar lordosis _____ and sacral base moves ______
anteriorly: postural flexion
What postural: middle transverse axis occurs with ____ and ______ according to anatomic nomeclature.
flexion and extension
In the postural: middle transverse axis, ____ occurs when the sacral base is moving anteriorly (nutation)
In postural: middle transverse axis,______ occurs when sacral base is moving posteriorly (counternutation)
The sacrum rotates tilts forward on the ______ side and thus creating a _____ sacral sulcus
weight bearing side, deep
The leftward rotation of the right base about the left axis occurs during the swing phase of the ___ leg
The rightward rotation of the left base about the right axis occurs during the swing phase of the ____ leg.
Normal sacral motion during ambulation only involves nuetral to anterior positioning of the sacrum around these oblique axes. The sacrum does not go into _____ position.