Gluteal Region and Hip

Question 1

Gluteus Maximus

Answer 1

Origin:
Ilium posterior to posterior gluteal line; dorsal surface of sacrum and coccyx; and sacrotuberous ligament

Insertion:
Most fibers end in iliotibial tract, which inserts into lateral condyle of tibia; some fibers insert on gluteal tuberosity of femur

Innervation:
Inferior Gluteal Nerve (L5, S1, S2)

Action:
Extends hip joint between flexed and standing positions and assists in its lateral rotation; steadies thigh and assists in rising from sitting position

Question 2

Gluteus Medius

Answer 2

Origin:
External surface of ilium between anterior and posterior gluteal lines

Insertion:
Lateral surface of greater trochanter of femur

Innervation:
Superior gluteal nerve (L4, L5, S1)

Action:
Abduct and anterior portions medially rotate hip joint; keep pelvis level when opposite limb is elevated

Question 3

Gluteus Minimus

Answer 3

Origin:
External surface of ilium between anterior and inferior gluteal lines

Insertion:
Anterior surface of greater trochanter of femur

Innervation:
Superior gluteal nerve (L4, L5, S1)

Action:
Abduct and anterior portions medially rotate hip joint; keep pelvis level when opposite limb is elevated

Question 4

Tensor Fascia Latae

Answer 4

Origin:
Anterior superior iliac spine; anterior part of iliac crest

Insertion:
Iliotibial tract, which attaches to lateral condyle of tibia (Gerdy tubercle)

Innervation:
Superior gluteal nerve (L4, L5, S1)

Action:
Flexes hip joint; acts with glu- teus maximus to stabilize the extended knee joint.

Question 5

Piriformis

Answer 5

(passes through greater sciatic foramen)

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:
Branches of anterior rami of S1, S2

Action:
Laterally rotate extended hip joint; abduct flexed hip joint; steady femoral head in acetabulum (stabilizes hip joint)

Question 6

Obturator Internus

Answer 6

(passes through lesser sciatic foramen)

Origin:
Pelvic surface of ilium and ischium; obturator membrane

Insertion:
Medial surface of greater trochanter (trochanteric fossa) of femur.

Innervation:
Nerve to obturator internus (L5, S1, S2)

Action:
Laterally rotate extended hip joint; abduct flexed hip joint; steady femoral head in acetabulum (stabilizes hip joint)

Question 7

Superior and Inferior Gemelli

Answer 7

Origin:
Superior: ischial spine
Inferior: ischial tuberosity

Insertion:
Medial surface of greater trochanter (trochanteric fossa) of femur.

Innervation:
Superior: same as obturator internus
Inferior: same as quadratus femoris

Action:
Laterally rotate extended hip joint; abduct flexed hip joint; steady femoral head in acetabulum (stabilizes hip joint)

Question 8

Quadratus Femoris

Answer 8

Origin:
Lateral border of ischial tuberosity

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

Innervation:
Nerve to quadratus femoris (L4, L5,S1)

Action:
Laterally rotates hip joint; also pulls femoral head into acetabulum to stabilize hip joint/pelvis.