OINA of pelvic wall, floor and gluteal muscles (semester 2 year 1)

Question 1

Obturator internus

Answer 1

Part of the lateral pelvic wall muscles

O-Pelivc surfaces of the illium and ischium; obturator membrane

I- greater trochanter of the femur

N- Nerve to obturator internus (L5,S1,S2)

A- rotate the thigh laterally; stabilises hip joint

Question 2

Piriformis

Answer 2

Part of the posterior superior pelvic wall muscles

O- Pelvic surface of S2-S4 segments; superior margin of greater sciatic notch and sacrotuberous ligament.

I- Greater trochanter of the femur

N- anterior Rami of S1 and S2 (nerve to piriformis)

A-rotates thigh laterally;abducts thigh; stabilises hip joint

Question 3

Coccygeus

Answer 3

Part of the pelvic floor muscles

O: Ischial spine

I: Inferior end of sacrum and coccyc

NS: nerve to coccygues

A: Support pelvic viscera, flexes coccyx

Question 4

Levator ani

Answer 4

Part of the pelvic floor muscles

Made up of three different muscles, coccygeus pubococcygeus and puborectalis

O:Body of pubis;tendinous arch of obturator fascia;ischial spine

I: Perineal body;coccyx;anococcygeal ligament

NS: nerve to levator ani, and coccygeal plexus

A: Support pelvic viscera and continence

Question 5

Gluteus maximus

Answer 5

Part of the gluteal muscles

O: Posterior to posterior gluteal line of the ilium, dorsal surface of sacrum and coccyx and sacrotuberous ligament

I- Blends onto ITB and the gluteal tuberosity

NS- inferior gluteal nerve

A- Extension of the thigh, assists in lateral rotation. Steadies the thigh and assists arising from sitting position

Question 6

Gluteus medius

Answer 6

Part of the gluteal muscles

O- anterior gluteal line of the ilium, external surface between anterior and posterior gluteal lines

I- Lateral surface of greater trochanter of femur

NS- superior gluteal nerve

A- Abduction, medial rotation of the thigh, keeps pelvis stable and horizontal during ipsilateral weight bearing

Question 7

Gluteus minimus

Answer 7

Part of the gluteal muscles

O- Between Anterior and inferior gluteal lines

I- Anterior surface of the greater trochanter of the femur

N- Superior gluteal nerve

A-Abduction, medial rotation of the thigh, keeps pelvis stable and horizontal during ipsilateral weight bearing

Question 8

Tensor fascia lata

Answer 8

Part of the gluteal muscles

O- ASIS to anterior portion of the iliac crest

I- Lateral condyle of the tibia, via iliotibial tract

N- Superior gluteal nerve

A- Abduct and medially rotate the thigh, flexes thigh