Muscles of Gluteal Region (2)

Question 0

Obturator Internus (passes through lesser sciatic foramen)

Answer 0

Origin: Pelvic surface of ilium and ischium; and obturator membrane

Insertion: Medial surface of greater trochanter (trochanteric fossa) of femur, (blends with Gemelli)

Innervation: Nerve to obturator internus (L5, S1)

Question 1

Piriformis (passes through greater sciatic foramen)

Answer 1

Origin: Anterior surface of 2nd-4th sacral segments; superior margin of greater sciatic notch, and sacrotuberous ligament

Insertion: Superior border of greater trochanter of femur

Innervation: Anterior branches of S1 & S2 rami

Question 2

Gemelli (superior and inferior)

Answer 2

Origin: (superior) ischial spine, (inferior) ischial tuberosity

Insertion: Medial surface of greater trochanter (trochanteric fossa) of femur, (blends with obturator internus)

Innervation: (superior) Nerve to obturator internus (L5,S1), (inferior) nerve to quadratus femoris (L5, S1)

Question 3

Quadratus Femoris

Answer 3

Origin: Lateral border of ischial tuberosity

Insertion: Quadrate tubercle on intertrochanteric crest of femur and area inferior to it

Innervation: Nerve to quadratus femoris (L5, S1)