Flashcards in Pelvic Girdle - Biomechanics Deck (79)
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1
What are the 4 ligaments of the pelvic girdle?
- Iliolumbar ligament
- Ventral sacroiliac ligament
- Sacrotuberous ligament
- Sacrospinous ligament
2
What ligament attaches the L-spine to the innominate bone?
Iliolumbar ligament
3
What are the 4 joints/ aspects of the pelvic girdle system?
- Lower L-spine
- Sacroiliac joints
- Pubic symphysis
- Hip joint
4
What type of joint is the pubic symphysis?
- Amphiarthrodial
5
What is the function of the pubic symphysis?
- Increases stability at the sacroiliac joints
6
What 2 structures provide stability at the pubic symphysis?
- Fibrocartilaginous disc
- Arcurate ligaments
7
What type of joints are the sacroiliac joints?
- Diarthrodial (synovial) --> Become amphiarodial with age
8
How do the shape of the articulations of the sacroiliac joints change with age?
- They are flat until puberty when they develop grooves and ridges
9
Which aspect of the sacroiliac joints are covered with hyaline cartilage, and which are covered with fibrocartilage? Which surface of the sacroiliac joint is thicker?
- Sacral surface covered with hyaline/ thicker
- Ilial surface covered in fibrocartilage
10
Which aspect of the sacroiliac joint is susceptible to osteoarthritis?
- Ilial surface
11
What is the shape of the articular surface of the SIJ in the sagittal plane?
- Kidney shaped
12
How is the long arm of the sacroiliac joint oriented?
Anterior-posterior
13
How is the short arm of the sacroiliac joint oriented?
Superior-inferior
14
At which levels of the sacrum does the sacroiliac joint articulate? (males/ females)
Males: S1 - S3/4
Females:S1 - S2
15
What spinal segments innervate the anterior capsule of the SIJ? Which spinal segments innervate the posterior capsule of the SIJ?
L2 - S2
L4 - S4
16
What are the 3 function sof the pelvic girdle?
- Base for superincumbent body weight
- Links the body to the lower extremities
- Supports the viscera
17
What 5 structures form the posterior arch of the pelvic girdle?
- Lower extremities
- Acetabulae
- Ilia
- Sacroiliac joint
- Upper 3 sacral vertebra
18
What 5 structures form the anterior arch of the pelvic girdle?
- Lower extremities
- Acetabulae
- Pubic bones
- Disc
- Pubic symphysis
19
Describe the 3 factors causing the keystone effect of the pelvic girdle.
- Innominate bones produce lateral to medial forces against the sacrum from the arches
- Sacrum is wider at base wedges into the innominate bones
- Body weight presses the sacrum into the innominate bones
20
What is meant by form closure?
- Structure of the bony arches creates stability
21
What is meant by force closure?
- Core muscles support pelvic girdle
- Transverse abdominis
- Pelvic floor muscles
- Diaphragm
- Lumbar multifidi
22
What are 2 common historical findings that may change form closure of the pelvis?
- Child birth
- Multitrauma (fall from heights, MVAs)
23
What are the 3 effects of a horizontally oriented sacrum?
- Increased lumbosacral angle
- Increased load to anterior ligaments
- More risk to SIJ
24
What are the 3 effects of a vertically oriented scarum?
- Decreased lordosis
- Loose packed position of lumbar spine
- More risk to lumbar spine
25
Which gender is more likely to have a horizontally oriented sacrum?
- Females
26
Which gender is more likely to have a vertically oriented sacrum?
- Male
27
What determines the shape of the SI joint?
- The development of the spinal curves
(more development --> more motion at SI joint)
28
Which sacral position is more dynamic? Which is more static?
Horizontal --> Dynamic
Vertical --> Static
29
What are the 3 axes of motion of the ilia? Through which structures do they pass, and what motion occurs around them?
Horizontal axis:
- Through SIJs
- Anterior/ posterior rotation
Oblique A/P axis
- Through SIJ and pubic symphysis
- Inflare/ outflare motion
Straight translation:
- Upslip / downslip motion
30
