Pelvis

Question 1

Osteology of Pelvis Structures

Answer 1

Osteoligamentous ring designed for stability

Question 2

The bones of the pelvic girdle consist of

Answer 2

2 innominate bones
Ilium
Ischium
Pubis
And the Sacrum dorsally

Question 3

Pelvis articulates with

Answer 3

both the axial and appendicular skeleton

With 5th vertebrae and with 2 femurs at hip joint

Question 4

5th lumbar vertebrae
Body
Height
Ingerior facet orientation
Transverse processes
Spinous process

Answer 4

Body - largest and heaviest
Height - great discrepency btw ant and post
Ingerior facet orientation - frontal plane
Transverse processes - shortest, project upward, posterolaterally
Spinous process - smallest

Question 5

Sacrum
Ant =
POst =

Answer 5

Anterior = concave
Posterior = convex

Question 6

Sacral Hiatus

Answer 6

Access to epidural space for caudal epidural blocks

Question 7

L5-S1 Junction

Answer 7

High degree of variation and malformation (most common sacralization or lumbarization)

Question 8

Sacrilzation

Answer 8

L5 is ossified with the sacrum

Question 9

Lumbarization

Answer 9

Separation of sacrum at S1

Question 10

Any shear force in LS joint is resisted by

Answer 10

Superior articular process

Question 11

Spondylolysis - what kind of foce

Answer 11

tensile

Question 12

Innominate Bones

Answer 12

Divided in 3 parts into acetabulum
Anterior superior = ilium
Anterior Inferior = pubis
Posterior inferior = ischium

Question 13

Complete ossification of innominate by

Answer 13

20-25 years

Question 14

Supracristal Plane

Answer 14

The transverse plane at the highest point of the iliac crests
Space btw L4 and L5
Used for assessing the height of the iliac crests
Can also be used for testing leg length discrepancy

Question 15

Leg length discrepency - 1 method

Answer 15

ASIS to medial malleolus

Question 16

Gender Diff in Pelvis - Pubic arch angle

Answer 16

50-60 M

90 F

Question 17

Gender diff in pelvis - Pelvis height

Answer 17

Longer M

Shorter F

Question 18

Gender diff in pelvis - Sacrum

Answer 18

Longer/Narrower M

Shorter/Wider F

Question 19

Gender diff in pelvis - Sacral Base Length

Answer 19

> 1/3 body M

Question 20

Gender diff in pelvis - Acetabular Distance

Answer 20

Smaller M

Greater F

Question 21

Gender diff in pelvis - ASIS distance

Answer 21

Smaller M

Greater F

Question 22

Pelvic Inlet angle

Answer 22

50-60 degrees

Question 23

Pelvic Outlet angle

Answer 23

15 degrees

Question 24

Super-incumbent weight at sacrum

Answer 24

Head, Arms, and Trunk (HAT)

No matter sitting or standing, weight is at the SI joint

Question 25

Joints of osteoligamentous ring

Answer 25

``` 2 SI joints (immovable synovial) Sacrum (modified vertebral column) Pubic symphysis (secondary cartilaginous joint) ```

Question 26

SI Joint - Joint surfaces

Answer 26

Internal surface of the ilium - behind iliac fossa, auricular sacral surface

Question 27

SI Joint - Inner surface of ilium

Answer 27

2 parts - upper tuberosity, lower auricular surface

Question 28

SI Joint - Tuberosity

Answer 28

Rough, for fibers of interosseous sacroiliac ligament

Question 29

SI Joint - Auricular Suface

Answer 29

Broad synovial joints btw the sacrum and ilium

Question 30

SI joint auricular surfaces - Form and Force Closure

Answer 30

These surfaces have irrefular elevations and depressions, which result in a partial interlocking of the bones THe strong articular capsule is attached close to the articulating surfaces of the sacrum and ilium

Question 31

Sacrum is

Answer 31

suspended btw iliac bones held together by interosseous and posterior sarcoiliac ligamnets Strongest ligaments in the body

Question 32

Ventral SI ligament

Answer 32

thin, wide sheet of transverse fibers anterior and inferior aspects of the SI joint Replacement of most or all of these fibers by bone often begins after 50 years of age

Question 33

Dorsal SI ligament

Answer 33

Strong, short transverse and long vertical fibers joining the ilium and sacrum The long fibers blend with the sacrotuberous ligament

Question 34

Interosseous Ligament

Answer 34

Massive, very strong ligament unites the iliac and sacral tuberosities Consists of short, strong bundles of fibers that blend with and are supported by the thick firm posterior sacroiliac ligaments

Question 35

SI joint movement - SI joint is supported by a

Answer 35

ligamentous viscoelastic structure that was built to stretch small amounts When you walk, short duration forces being placed across it by your foot hitting the ground and the bending of the spine cause it to stretch and store energy This energy is released by swinging your leg forward However - sitting causes some lengthening and stretching of the ligamentous structures

Question 36

SI joint motion

Answer 36

Symmetrical Assymetrical Lumbopelvic

Question 37

Symmetrical SI joint motion

Answer 37

Sacrum in relation to innominates (both) | Nutation and counternutation

Question 38

Asymmetrical SI joint motion

Answer 38

Motion of one innominate relative to the other Sacral or pelvic torsion Movement at the pubic symphysis - greater with pregnancy and delivery

Question 39

Lumbopelvic SI joint motion

Answer 39

Lumbar spine and sacrum with the innominates relative to the femurs (hip joint motion)

Question 40

Anterior Nutation

Answer 40

Sacral on Iliac

Question 41

Posterior Nutation

Answer 41

Ilium on Sacral

Question 42

Counter Nutation - Anterior

Answer 42

Ilium on Sacral

Question 43

Counter nutation - posterior

Answer 43

Sacral on ilium

Question 44

Nutation icnreases

Answer 44

the compression and shear forces at SI joint (stablity

Question 45

Full nutation of SI joint

Answer 45

in close packed position

Question 46

Pelvic Structure at SI joint

Answer 46

Sacrum is wider ant than post Sacrum behaves as reverse keystone tending to sink into pelvis POst ligaments become taut and draw iliac bones closer to each other then interlock the iliac bones with the sacrum

Question 47

Rotation tendencies of pelvis due to superincumban weight - Nutation

Answer 47

Sacrum - Forward rotation at S1 | Resisted by interosseous, dorsal sacroiliac and iliolumbar ligaments

Question 48

Rotation tendencies of pelvis due to superincumbent weight - Lumbopelvic

Answer 48

Os-Coxae = backward rotation at hip | Resisted by sacrotuberous and sacrospinous ligaments

Question 49

Forces at SI joint during one leg stance

Answer 49

Wight, GRF, JRF, and muscle forces and ligaments will determine the 3D motion btw the bones of the SI joint A lot of the forces in this joint and support of it experience a lot of tension on a consist basis