Pelvic Exam II Flashcards
what are the parts of the pelvis?
Two innominate bones, pubic symphysis, and sacrum.
what is the joint of the sacrum and the innominate bones?
the sacroiliac joints
what bones fuse to make the innominate?
ilium, ischium and pubis
what type of joint is the pubic symphysis?
amphiarthrosis, its slightly movable fibrocartliganeous disk
where is the median sacral crest?
the second sacral tubercle.
why is are the sacroiliac joints atypical?
because they have irregular joint surfaces for a synovial diarthrotic joint
features of sacroiliac joint?
synovial, fibrocartilage, central convex ridge, heavy ligaments on posterior and superior surfaces
what is the shape of the SI joint on the sacram?
boot shape with a concave central joint
does the SI joint have hyline cartilage?
yes
what hold SI joint together?
It has sacroiliac joint at bottom with the interosseous sacroiliac ligament connecting the bones above that
What connects L-5 and S1 (Z joint) to the innominate?
Iliolumbar ligament
what is the keysone effect?
the sacrum forms an arch suspended by stond sacroiliac ligaments. Resists displacement
what part of sacroiliac joint resists inferior displacement?
Inferior displacement is resisted by the sacrums wedge shape
Wht part of the sacroiliac joint resists posterior displacement?
Posterior displacement is resisted by sacroiliac ligaments
What part of sacroiliac joint resists anterior displacement?
Anterior displacement is resisted by sacroiliac ligaments and the symphysis pubus
what part of SI joint has the groove and wedge?
sacrum has a grove and the ilium has the ridge.
what parts of SI joint promotes stability, 3 things
wedge shape, interlocking grove and ridge, and s shaped joint surfaces.
what is force closure of SI joint?
tension in muscles ligaments and fascia aids in stabilizing the si joints.
what pressure does the force closure create?
creates lateral to medial pressure to compress the SI joint
what is the force closure muscles called for SI?
the posterior myofascial sling
what transmists force between lower extremity and axial skeleton?
the pelvis.
does the SI joint/pelvis move?
yes, it slides and pivots to absorb and adapt to forces generated between trunk and lowwer extremities during walking.
what does the movement of the pelvis do?
decreases sttress to lumbar spine and opposite si joint.
what is nutation?
sacroiliac motion where the sacral base rotates forward on iliam, or the ilium rotates back on sacrum.
what is counter nutation?
where sacrum tilts back on illium or the ilium tilts foreward on sacrum
nutation creates what movment/rotation?
the anterior sacral tilt /posterior iliac tilt causes increased lumbar lordotic curve
counter nutation creates what?
decreases the lumbar lordotic curve when the sacrum tilts posteriorly
movements at pubic symphysis?
compression, distraction, rotation in sagital plane with SI, gliding anterior posterior and superior inferior
what is the force couple of anterior pelvic tilt?
Hip flexors - iliospoas and rectus femoras pull down on the front, the back extensors- erector spina pull up on the back tilting everything forward.
What is the force couple for posterior pelvic tilt?
Hip extensors - glut max and hamstrings pull the the back down, Abdominal muscles- rectus abdominus and obliquus externus pull the front up.
