Gluteal region and external rotators of the hip muscles

Question 1

Gluteus maximus
* origin
* insertion
* action
* innervation

Answer 1

• origin: thoracolumbar fascia; gluteal fossa of the iliac wing, sacrotuberous ligament, posterior and inferior sacrum and coccyx
• insertion: gluteal tuberosity of the femur; iliotibial band
• action: extension of thigh; external rotation of thigh; abduction of thigh
• innervation: inferior gluteal nerve

Question 2

Gluteus medius
* origin
* insertion
* action
* innervation

Answer 2

• origin: gluteal fossa of iliac wing
• insertion: greater trochanter of femur
• action: abduction of thigh; mainly stabilizer of a pelvis (with all working together)
  anterior fibres: internal rotation of thigh
  posterior fibres: external rotation of the thigh at the hip
• innervation: superior gluteal nerve

Question 3

Gluteus minimus
* origin
* insertion
* action
* innervation

Answer 3

• origin: gluteal fossa of the iliac wing
• insertion: greater trochanter of the femur
• action: abduction of the thigh
  anterior portion: internal rotation of the thigh (only)
• innervation: superior gluteal nerve

Question 4

Tensor fascia latae
* origin
* insertion
* action
* innervation

Answer 4

• origin: anterior superior iliac spine
• insertion: iliotibial tract
• action: abduction of the thigh at the hip (with gluteus maximus); flexion of the thigh, internal rotation of thigh
• innervation: superior gluteal nerve

Question 5

Piriformis
* origin
* insertion
* action
* innervation

Answer 5

• origin: anterior surface of sacrum
• insertion: greater trochanter of the femur
• action: external rotation of thigh, abduction of thigh
• innervation: branches of sacral plexus

Question 6

Superior gemellus
* origin:
* insertion:
* action:
* innervation:

Answer 6

• origin: spine of ischium
• insertion: greater trochanter of the femur
• action: external rotation of the thigh; abduction of the thigh
• innervation: branches of the sacral plexus

Question 7

Obturator internus
* origin:
* insertion:
* action:
* innervation:

Answer 7

• origin: posterior surface of obturator membrane
• insertion: greater trochanter of the femur; trochanteric fossa
• action: external rotation of the thigh
• innervation: branches of the sacral plexus

Question 8

Inferior gemellus
* origin:
* insertion:
* action:
* innervation:

Answer 8

• origin: tuberosity of the ischium
• insertion: greater trochanter of the femur
• action: external rotation of the thigh; abduction of the thigh
• innervation: branches of the sacral plexus

Question 9

Obturator externus
* origin:
* insertion:
* action:
* innervation:

Answer 9

• origin: anterior surface of obturator membrane
• insertion: trochanteric fossa
• action: external rotation of the thigh; adduction of the thigh
• innervation: obturator nerve

Question 10

Quadratus femoris
* origin:
* insertion:
* action:
* innervation:

Answer 10

• origin: tuberosity of the ischium
• insertion: intertrochanteric crest of the femur
• action: external rotation of the thigh; adduction of the thigh
• innervation: branches of the sacral plexus (nerve to quadratus femoris)

Question 11

How many muscles insert on the greater trochanter? List them

Answer 11

7! ^_^
* gluteus medius
* gluteus minimus
* piriformis
* superior gemellus
* obturator internus
* inferior gemellus
* vastus lateralis