Posterior Hip

Question 1

Gluteus Maximus

Answer 1

Origin: Posterior iliac crest, sacrum, coccyx, sacrotuberous ligament, thoracolumbar fascia

Insertion: Iliotibial band, gluteal tuberosity of femur

Action: Hip extension, abduction, lateral rotation, resists knee varus, (in weight-bearing, stabilises pelvis)

Innervation: Inferior gluteal nerve (L5, S1, S2)

Question 2

Piriformis (deep posterior)

Answer 2

Origin: Anterior sacrum

Insertion: Greater trochanter of femur

Action: Hip lateral rotation

Innervation: L5, S1, S2 ventral rami

Question 3

Gemellus Superior (deep posterior)

Answer 3

Origin: Ischial spine

Insertion: Greater trochanter of femur

Action: Hip lateral rotation

Innervation: Nerve to obturator internus (L5, S1)

Question 4

Obturator Internus (deep posterior)

Answer 4

Origin: Internal surface of obturator foramen and membrane

Insertion: Greater trochanter of femur

Action: Hip lateral rotation

Innervation: Nerve to obturator internus (L5, S1)

Question 5

Gemellus Inferior (deep posterior)

Answer 5

Origin: Ischial tuberosity

Insertion: Greater trochanter of femur

Action: Hip lateral rotation

Innervation: Nerve to quadratus femoris (L5, S1)

Question 6

Quadratus Femoris (deep posterior)

Answer 6

Origin: Lateral aspect of ischium anteiror to ischial tuberosity

Insertion: Quadrate tubercle on intertrochanteric crest of femur

Action: Hip lateral flexion, (weak hip adduction)

Innervation: Nerve to quadratus femoris (L5, S1)