Pelvis

Question 1

Ligaments

Answer 1

Long posterior sacroiliac ligament:
– limit anterior pelvic rotation or sacral counternutation

Short posterior sacroiliac ligament:
– limits all pelvic and sacral movement

posterior interosseous ligament:
– forms part of the sacroiliac articulation, and the anterior sacroiliac ligaments

Sacrotuberous ligament:
– provide vertical stability
– limit nutation and posterior innominate rotation

Sacrospinous ligament:
– provide vertical stability
– limit nutation and posterior innominate rotation

(pedundal nerve entrapment between the sacrotuberous and sacrospinous can occur and is one of the most common pedundal nerve pathologies that can cause pelvic pain).

Iliolumbar ligament:
– stabilises L5 on the ilium and prevents anterior displacement of L5 (spondylolisthesis)

Question 2

Symphysis pubis

Answer 2

Fibrocartilaginous joint held together by the pubic ligament
Allows limited movement

Question 3

Sacrococcygeal joint

Answer 3

Usually a fused line (symphysis) united by a fibrocartilaginous disc
Found between the apex of the sacrum and the base of the coccyx.

Question 4

Pelvic floor

Answer 4

dome-shaped muscular sheet separating the pelvic cavity above from the perineal region

Question 5

Main function of pelvic floor:

Answer 5

Support the abdominal and pelvis viscera

To maintain the continence of urine and faeces

Allows voiding, defection, sexual activity, and childbirth

3 layers of muscle:
– layer 1- urogenital triangle

– Layer 2- urogenital diaphragm

– Layer 3- pelvic diaphragm:
– levator ani muscle
– coccygeus
– piriformis
– obturator internus