Q2 Joints of the Pelvic Girdle

Question 1

Give the position and name the bones contributing to these joints

Answer 1

Pubic symphysis:
Bones: Most medial aspect of the pubic bones.
Position: Anterior articulation of pelvis.
Sacroiliac joint:
Bones: ilium and sacrum.
Position: Posterior articulation of the pelvis formed between the auricular surface of the ilium and the auricular surface of the ala of the sacrum.

Question 2

State the type of joint in each case

Answer 2

Sacroiliac joint: synovial plane joint. Fibrous posteriorly

Pubic symphysis: secondary cartilaginous joint.

Question 3

For the Pubic Symphysis only, describe the articular surfaces and their arrangement

Answer 3

Each bone is covered by a layer of hyaline cartilage and joined to the cartilage on the opposite side by a fibrocartilage disc (interpubic disc).

Question 4

For each joint name the ligaments which strengthen that joint

Answer 4

Pubic symphysis: 
Superior pubic ligament 
Arcuate pubic ligament 
Interpubic disc 
Sacroiliac joint:
Anterior sacroiliac ligament
Interosseous Ligament.
Iliolumbar ligament 
Sacrotuberous Ligament
Sacrospinous Ligament

Question 5

Name the movements that occur at the SI joint

Answer 5

Nutation and counter nutation