Muscles of the Pelvis

Question 1

Iliacus

Answer 1

attachments- from iliac fossa to lesser trochanter of femur

actions- flexion of thigh at the hip joint

innervation- femoral nerve

Question 2

Psoas major

Answer 2

attachments- from transverse processes of T12-L4 to lesser trochanter of femur

actions- flexion of thigh at the hip joint

innervation- ventral rami L1-L3

Question 3

Piriformis (L. pirum, pear)

Answer 3

attachments- from sacrum to greater trochanter of femur

actions- lateral rotation of thigh at the hip joint

innervation- nerve to piriformis

Question 4

Obturator internus

Answer 4

attachments- from obturator membrane to greater trochanter of femur

actions- lateral rotation of thigh at the hip joint

innervation- nerve to obturator internus (L5-S1)

Question 5

(pelvic floor/diaphragm)

Coccygeus

Answer 5

attachments- ischial spine & sacrospinous ligament to coccyx

actions- supports & compresses posterior pelvic floor

innervation- ventral rami S4-5

Question 6

(pelvic floor/diaphragm; Levator ani. m.)

Iliococcygeus

Answer 6

attachments- from ischium & tendinous arch of obturator internus to coccyx & midline raphe

action- support pelvic viscera

innervation- levator ani nerve (S4), inferior rectal nerve (pudendal S3-4), coccygeal plexus

Question 7

(pelvic floor/diaphragm; Levator ani. m.)

Pubococcygeus

Answer 7

attachments- pubis & tendinous arch of obturator internus to coccyx & midline raphe & walls of prostate or vagina

actions- support pelvic viscera & compress vagina

innervation- levator ani nerve (S4), inferior rectal nerve (pudendal S3-4), coccygeal plexus

Question 8

(pelvic floor/diaphragm; Levator ani. m.)

Puborectalis

Answer 8

attachments- pubis & wall of rectum

actions- maintain fecal continence

innervation- levator ani nerve (S4)